1614 lines
47 KiB
Plaintext
1614 lines
47 KiB
Plaintext
# Code for the first few disk sectors that all programs in this directory need:
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# - load sectors past the first (using BIOS primitives) since only the first is available by default
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# - if this fails, print 'D' at top-left of screen and halt
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# - initialize a minimal graphics mode
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# - switch to 32-bit mode (giving up access to BIOS primitives)
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# - set up a handler for keyboard events
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# - jump to start of program
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# Code in this file needs to be more deliberate about the SubX facilities it
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# uses:
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# - sigils only support 32-bit general-purpose registers, so don't work with segment registers or 16-bit or 8-bit registers
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# - metadata like rm32 and r32 can sometimes misleadingly refer to only the bottom 16 bits of the register; pay attention to the register name
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#
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# While most of Mu is thoroughly tested, this file is not. I don't yet
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# understand hardware interfaces well enough to explain to others.
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# Memory map of a Mu computer:
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# code: currently 4 tracks loaded from the primary disk to [0x00007c00, 0x00048600)
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# stack: grows down from 0x02000000 to 0x01000000
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# heap: [0x02000000, 0x08000000)
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# see 120allocate.subx; Qemu initializes with 128MB RAM by default
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# Consult https://wiki.osdev.org/Memory_Map_(x86) before modifying any of
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# this. And don't forget to keep *stack-debug.subx in sync.
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== code
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## 16-bit entry point: 0x7c00
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# Upon reset, the IBM PC:
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# - loads the first sector (512 bytes)
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# from some bootable image (look for the boot-sector-marker further down this file)
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# to the address range [0x7c00, 0x7e00)
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# - starts executing code at address 0x7c00
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fa/disable-interrupts
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# initialize segment registers
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b8/copy-to-ax 0/imm16
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8e/->seg 3/mod/direct 0/rm32/ax 3/r32/ds
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8e/->seg 3/mod/direct 0/rm32/ax 0/r32/es
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8e/->seg 3/mod/direct 0/rm32/ax 4/r32/fs
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8e/->seg 3/mod/direct 0/rm32/ax 5/r32/gs
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# Temporarily initialize stack to 0x00070000 in real mode.
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# We don't read or write the stack before we get to 32-bit mode, but BIOS
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# calls do. We need to move the stack in case BIOS initializes it to some
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# low address that we want to write code into.
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b8/copy-to-ax 0x7000/imm16
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8e/->seg 3/mod/direct 0/rm32/ax 2/r32/ss
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bc/copy-to-esp 0/imm16
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# undo the A20 hack: https://en.wikipedia.org/wiki/A20_line
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# this is from https://github.com/mit-pdos/xv6-public/blob/master/bootasm.S
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{
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e4/read-port-into-al 0x64/imm8
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a8/test-bits-in-al 0x02/imm8 # set zf if bit 1 (second-least significant) is not set
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75/jump-if-!zero loop/disp8
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b0/copy-to-al 0xd1/imm8
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e6/write-al-into-port 0x64/imm8
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}
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{
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e4/read-port-into-al 0x64/imm8
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a8/test-bits-in-al 0x02/imm8 # set zf if bit 1 (second-least significant) is not set
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75/jump-if-!zero loop/disp8
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b0/copy-to-al 0xdf/imm8
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e6/write-al-into-port 0x64/imm8
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}
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# load remaining sectors from first two tracks of disk into addresses [0x7e00, 0x17800)
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b4/copy-to-ah 2/imm8/read-drive
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# dl comes conveniently initialized at boot time with the index of the device being booted
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b5/copy-to-ch 0/imm8/cylinder
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b6/copy-to-dh 0/imm8/head
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b1/copy-to-cl 2/imm8/sector # 1-based
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b0/copy-to-al 0x7d/imm8/num-sectors # 2*63 - 1 = 125
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# address to write sectors to = es:bx = 0x7e00, contiguous with boot segment
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bb/copy-to-bx 0/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es
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bb/copy-to-bx 0x7e00/imm16
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cd/syscall 0x13/imm8/bios-disk-services
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0f 82/jump-if-carry disk_error/disp16
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# load two more tracks of disk into addresses [0x17800, 0x27400)
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b4/copy-to-ah 2/imm8/read-drive
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# dl comes conveniently initialized at boot time with the index of the device being booted
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b5/copy-to-ch 0/imm8/cylinder
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b6/copy-to-dh 2/imm8/head
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b1/copy-to-cl 1/imm8/sector # 1-based
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b0/copy-to-al 0x7e/imm8/num-sectors # 2*63 = 126
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# address to write sectors to = es:bx = 0x17800, contiguous with boot segment
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bb/copy-to-bx 0x1780/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es
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bb/copy-to-bx 0/imm16
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cd/syscall 0x13/imm8/bios-disk-services
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0f 82/jump-if-carry disk_error/disp16
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# load two more tracks of disk into addresses [0x27400, 0x37000)
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b4/copy-to-ah 2/imm8/read-drive
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# dl comes conveniently initialized at boot time with the index of the device being booted
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b5/copy-to-ch 0/imm8/cylinder
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b6/copy-to-dh 4/imm8/head
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b1/copy-to-cl 1/imm8/sector # 1-based
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b0/copy-to-al 0x7e/imm8/num-sectors # 2*63 = 126
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# address to write sectors to = es:bx = 0x27400, contiguous with boot segment
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bb/copy-to-bx 0x2740/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es
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bb/copy-to-bx 0/imm16
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cd/syscall 0x13/imm8/bios-disk-services
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0f 82/jump-if-carry disk_error/disp16
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# load two more tracks of disk into addresses [0x37000, 0x46c00)
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b4/copy-to-ah 2/imm8/read-drive
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# dl comes conveniently initialized at boot time with the index of the device being booted
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b5/copy-to-ch 0/imm8/cylinder
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b6/copy-to-dh 6/imm8/head
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b1/copy-to-cl 1/imm8/sector # 1-based
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b0/copy-to-al 0x7e/imm8/num-sectors # 2*63 = 126
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# address to write sectors to = es:bx = 0x37000, contiguous with boot segment
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bb/copy-to-bx 0x3700/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es
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bb/copy-to-bx 0/imm16
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cd/syscall 0x13/imm8/bios-disk-services
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0f 82/jump-if-carry disk_error/disp16
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# reset es
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bb/copy-to-bx 0/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es
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# adjust video mode
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b4/copy-to-ah 0x4f/imm8 # VBE commands
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b0/copy-to-al 2/imm8 # set video mode
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bb/copy-to-bx 0x4105/imm16 # 0x0105 | 0x4000
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# 0x0105 = graphics mode 1024x768x256
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# (alternative candidate: 0x0101 for 640x480x256)
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# 0x4000 bit = configure linear frame buffer in Bochs emulator; hopefully this doesn't hurt anything when running natively
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cd/syscall 0x10/imm8/bios-video-services
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# load information for the (hopefully) current video mode
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# mostly just for the address to the linear frame buffer
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b4/copy-to-ah 0x4f/imm8 # VBE commands
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b0/copy-to-al 1/imm8 # get video mode info
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b9/copy-to-cx 0x0105/imm16 # mode we requested
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bf/copy-to-di Video-mode-info/imm16
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cd/syscall 0x10/imm8/bios-video-services
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## switch to 32-bit mode
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# load global descriptor table
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# We can't refer to the label directly because SubX doesn't do the right
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# thing for lgdt, so rather than make errors worse in most places we instead
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# pin gdt_descriptor below.
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0f 01 2/subop/lgdt 0/mod/indirect 6/rm32/use-disp16 0x7ce0/disp16/gdt_descriptor
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# enable paging
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0f 20/<-cr 3/mod/direct 0/rm32/eax 0/r32/cr0
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66 83 1/subop/or 3/mod/direct 0/rm32/eax 1/imm8 # eax <- or 0x1
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0f 22/->cr 3/mod/direct 0/rm32/eax 0/r32/cr0
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# far jump to initialize_32bit_mode that sets cs to offset 8 in the gdt in the process
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# We can't refer to the label directly because SubX doesn't have syntax for
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# segment selectors. So we instead pin initialize_32bit_mode below.
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ea/jump-far-absolute 0x00087d00/disp32 # address 0x7d00 in offset 8 of the gdt
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disk_error:
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# print 'D' to top-left of screen to indicate disk error
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# *0xb8000 <- 0x0f44
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bb/copy-to-bx 0xb800/imm16
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8e/->seg 3/mod/direct 3/rm32/bx 3/r32/ds
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b0/copy-to-al 0x44/imm8/D
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b4/copy-to-ah 0x0f/imm8/white-on-black
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bb/copy-to-bx 0/imm16
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89/<- 0/mod/indirect 7/rm32/bx 0/r32/ax # *ds:bx <- ax
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# loop forever
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{
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eb/jump loop/disp8
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}
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## GDT: 3 records of 8 bytes each
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== data 0x7ce0
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gdt_descriptor:
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0x17/imm16 # final index of gdt = size of gdt - 1
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gdt_start/imm32/start
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gdt_start:
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# offset 0: gdt_null: mandatory null descriptor
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00 00 00 00 00 00 00 00
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# offset 8: gdt_code
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ff ff # limit[0:16]
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00 00 00 # base[0:24]
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9a # 1/present 00/privilege 1/descriptor type = 1001b
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# 1/code 0/conforming 1/readable 0/accessed = 1010b
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cf # 1/granularity 1/32-bit 0/64-bit-segment 0/AVL = 1100b
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# limit[16:20] = 1111b
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00 # base[24:32]
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# offset 16: gdt_data
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ff ff # limit[0:16]
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00 00 00 # base[0:24]
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92 # 1/present 00/privilege 1/descriptor type = 1001b
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# 0/data 0/conforming 1/readable 0/accessed = 0010b
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cf # same as gdt_code
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00 # base[24:32]
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# gdt_end:
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## 32-bit code from this point
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== code 0x7d00
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initialize_32bit_mode:
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66 b8/copy-to-ax 0x10/imm16 # offset 16 from gdt_start
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8e/->seg 3/mod/direct 0/rm32/ax 3/r32/ds
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8e/->seg 3/mod/direct 0/rm32/ax 2/r32/ss
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8e/->seg 3/mod/direct 0/rm32/ax 0/r32/es
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8e/->seg 3/mod/direct 0/rm32/ax 4/r32/fs
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8e/->seg 3/mod/direct 0/rm32/ax 5/r32/gs
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bc/copy-to-esp 0x02000000/imm32
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## load interrupt handlers
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# We can't refer to the label directly because SubX doesn't do the right
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# thing for lidt, so rather than make errors worse in most places we instead
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# pin idt_descriptor below.
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0f 01 3/subop/lidt 0/mod/indirect 5/rm32/use-disp32 0x7e00/disp32/idt_descriptor
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# For now, not bothering reprogramming the IRQ to not conflict with software
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# exceptions.
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# https://wiki.osdev.org/index.php?title=8259_PIC&oldid=24650#Protected_Mode
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#
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# Interrupt 1 (keyboard) conflicts with debugger faults. We don't use a
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# debugger.
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# Reference:
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# https://wiki.osdev.org/Exceptions
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# enable timer IRQ0 and keyboard IRQ1
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b0/copy-to-al 0xfc/imm8 # disable mask for IRQ0 and IRQ1
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e6/write-al-into-port 0x21/imm8
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fb/enable-interrupts
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(initialize-mouse)
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## enable floating point
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db/floating-point-coprocessor e3/initialize
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# eax <- cr4
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0f 20/<-cr 3/mod/direct 0/rm32/eax 4/r32/cr4
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# eax <- or bit 9
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0f ba/bit-test 5/subop/bit-test-and-set 3/mod/direct 0/rm32/eax 9/imm8
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# cr4 <- eax
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0f 22/->cr 3/mod/direct 0/rm32/eax 4/r32/cr4
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e9/jump Entry/disp32
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== boot-sector-marker 0x7dfe
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# final 2 bytes of boot sector
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55 aa
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## sector 2 onwards loaded by load_disk, not automatically on boot
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== data 0x7e00
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idt_descriptor:
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ff 03 # final index of idt = size of idt - 1
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idt_start/imm32/start
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# interrupt descriptor table {{{
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# 32 entries of 8 bytes each
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idt_start:
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# entry 0
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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# By default, BIOS maps IRQ0-7 to interrupt vectors 8-15.
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# https://wiki.osdev.org/index.php?title=Interrupts&oldid=25102#Default_PC_Interrupt_Vector_Assignment
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# entry 8: https://wiki.osdev.org/Programmable_Interval_Timer
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timer-interrupt-handler/imm16 # target[0:16]
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8/imm16 # segment selector (gdt_code)
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00 # unused
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8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate
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0/imm16 # target[16:32] -- null-interrupt-handler must be within address 0x10000
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# entry 9: keyboard
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keyboard-interrupt-handler/imm16 # target[0:16]
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8/imm16 # segment selector (gdt_code)
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00 # unused
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8e # 1/p 00/dpl 0 1110/type/32-bit-interrupt-gate
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0/imm16 # target[16:32] -- keyboard-interrupt-handler must be within address 0x10000
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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00 00 00 00 00 00 00 00
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# idt_end:
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# }}}
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== code
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null-interrupt-handler:
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# prologue
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# Don't disable interrupts; the timer has the highest priority anyway,
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# and this interrupt triggers extremely frequently.
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fa/disable-interrupts
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60/push-all-registers
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9c/push-flags
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# acknowledge interrupt
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b0/copy-to-al 0x20/imm8
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e6/write-al-into-port 0x20/imm8
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31/xor %eax 0/r32/eax
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$null-interrupt-handler:epilogue:
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# epilogue
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9d/pop-flags
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61/pop-all-registers
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fb/enable-interrupts
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cf/return-from-interrupt
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timer-interrupt-handler:
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# prologue
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# Don't disable interrupts; the timer has the highest priority anyway,
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# and this interrupt triggers extremely frequently.
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fa/disable-interrupts
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60/push-all-registers
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9c/push-flags
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# acknowledge interrupt
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b0/copy-to-al 0x20/imm8
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e6/write-al-into-port 0x20/imm8
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31/xor %eax 0/r32/eax
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$timer-interrupt-handler:epilogue:
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# epilogue
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9d/pop-flags
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61/pop-all-registers
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fb/enable-interrupts
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cf/return-from-interrupt
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keyboard-interrupt-handler:
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# prologue
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fa/disable-interrupts
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60/push-all-registers
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9c/push-flags
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# acknowledge interrupt
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b0/copy-to-al 0x20/imm8
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e6/write-al-into-port 0x20/imm8
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31/xor %eax 0/r32/eax
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# check output buffer of 8042 keyboard controller (https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html)
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e4/read-port-into-al 0x64/imm8
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a8/test-bits-in-al 0x01/imm8 # set zf if bit 0 (least significant) is not set
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0f 84/jump-if-not-set $keyboard-interrupt-handler:epilogue/disp32
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# - if keyboard buffer is full, return
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# var dest-addr/ecx: (addr byte) = (keyboard-buffer + *keyboard-buffer:write)
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31/xor %ecx 1/r32/ecx
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8a/byte-> *Keyboard-buffer:write 1/r32/cl
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81 0/subop/add %ecx Keyboard-buffer:data/imm32
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# al = *dest-addr
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8a/byte-> *ecx 0/r32/al
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# if (al != 0) return
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3c/compare-al-and 0/imm8
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0f 85/jump-if-!= $keyboard-interrupt-handler:epilogue/disp32
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# - read keycode
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e4/read-port-into-al 0x60/imm8
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# - key released
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# if (al == 0xaa) shift = false # left shift is being lifted
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{
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3c/compare-al-and 0xaa/imm8
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75/jump-if-!= break/disp8
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# *shift = 0
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c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32
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}
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# if (al == 0xb6) shift = false # right shift is being lifted
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{
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3c/compare-al-and 0xb6/imm8
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75/jump-if-!= break/disp8
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# *shift = 0
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c7 0/subop/copy *Keyboard-shift-pressed? 0/imm32
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}
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# if (al == 0x9d) ctrl = false # ctrl is being lifted
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{
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3c/compare-al-and 0x9d/imm8
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75/jump-if-!= break/disp8
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# *ctrl = 0
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c7 0/subop/copy *Keyboard-ctrl-pressed? 0/imm32
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}
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# if (al & 0x80) a key is being lifted; return
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50/push-eax
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24/and-al-with 0x80/imm8
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3c/compare-al-and 0/imm8
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58/pop-to-eax
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75/jump-if-!= $keyboard-interrupt-handler:epilogue/disp8
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# - key pressed
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# if (al == 0x2a) shift = true, return # left shift pressed
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{
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3c/compare-al-and 0x2a/imm8
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75/jump-if-!= break/disp8
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# *shift = 1
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c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32
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# return
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eb/jump $keyboard-interrupt-handler:epilogue/disp8
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}
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# if (al == 0x36) shift = true, return # right shift pressed
|
|
{
|
|
3c/compare-al-and 0x36/imm8
|
|
75/jump-if-!= break/disp8
|
|
# *shift = 1
|
|
c7 0/subop/copy *Keyboard-shift-pressed? 1/imm32
|
|
# return
|
|
eb/jump $keyboard-interrupt-handler:epilogue/disp8
|
|
}
|
|
# if (al == 0x1d) ctrl = true, return
|
|
{
|
|
3c/compare-al-and 0x1d/imm8
|
|
75/jump-if-!= break/disp8
|
|
# *ctrl = 1
|
|
c7 0/subop/copy *Keyboard-ctrl-pressed? 1/imm32
|
|
# return
|
|
eb/jump $keyboard-interrupt-handler:epilogue/disp8
|
|
}
|
|
# - convert key to character
|
|
# if (shift) use keyboard shift map
|
|
{
|
|
81 7/subop/compare *Keyboard-shift-pressed? 0/imm32
|
|
74/jump-if-= break/disp8
|
|
# sigils don't currently support labels inside *(eax+label)
|
|
05/add-to-eax Keyboard-shift-map/imm32
|
|
8a/byte-> *eax 0/r32/al
|
|
eb/jump $keyboard-interrupt-handler:select-map-done/disp8
|
|
}
|
|
# if (ctrl) al = *(ctrl map + al)
|
|
{
|
|
81 7/subop/compare *Keyboard-ctrl-pressed? 0/imm32
|
|
74/jump-if-= break/disp8
|
|
05/add-to-eax Keyboard-ctrl-map/imm32
|
|
8a/byte-> *eax 0/r32/al
|
|
eb/jump $keyboard-interrupt-handler:select-map-done/disp8
|
|
}
|
|
# otherwise al = *(normal map + al)
|
|
05/add-to-eax Keyboard-normal-map/imm32
|
|
8a/byte-> *eax 0/r32/al
|
|
$keyboard-interrupt-handler:select-map-done:
|
|
# - if there's no character mapping, return
|
|
{
|
|
3c/compare-al-and 0/imm8
|
|
74/jump-if-= break/disp8
|
|
# - store al in keyboard buffer
|
|
88/<- *ecx 0/r32/al
|
|
# increment index
|
|
fe/increment-byte *Keyboard-buffer:write
|
|
# clear top nibble of index (keyboard buffer is circular)
|
|
80 4/subop/and-byte *Keyboard-buffer:write 0x0f/imm8
|
|
}
|
|
$keyboard-interrupt-handler:epilogue:
|
|
# epilogue
|
|
9d/pop-flags
|
|
61/pop-all-registers
|
|
fb/enable-interrupts
|
|
cf/return-from-interrupt
|
|
|
|
== data
|
|
Keyboard-shift-pressed?: # boolean
|
|
0/imm32
|
|
|
|
Keyboard-ctrl-pressed?: # boolean
|
|
0/imm32
|
|
|
|
# var keyboard circular buffer
|
|
Keyboard-buffer:write: # nibble
|
|
0/imm32
|
|
Keyboard-buffer:read: # nibble
|
|
0/imm32
|
|
Keyboard-buffer:data: # byte[16]
|
|
00 00 00 00
|
|
00 00 00 00
|
|
00 00 00 00
|
|
00 00 00 00
|
|
|
|
# Keyboard maps for translating keys to ASCII {{{
|
|
Keyboard-normal-map:
|
|
00
|
|
# es
|
|
1b
|
|
# |<--- digits -------------->| - = backspace
|
|
31 32 33 34 35 36 37 38 39 30 2d 3d 08
|
|
# 0f
|
|
# tab q w e r t y u i o p [ ]
|
|
09 71 77 65 72 74 79 75 69 6f 70 5b 5d
|
|
# 1c
|
|
# enter (newline)
|
|
0a 00
|
|
# 1e
|
|
# a s d f g h j k l ; ' ` \
|
|
61 73 64 66 67 68 6a 6b 6c 3b 27 60 00 5c
|
|
# ^ left shift
|
|
# 2c
|
|
# z x c v b n m , . / *
|
|
7a 78 63 76 62 6e 6d 2c 2e 2f 00 2a
|
|
# ^ right shift
|
|
# 38
|
|
# space
|
|
00 20
|
|
# 3a
|
|
00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00
|
|
# 48
|
|
# ↑* ←* →* ↓*
|
|
82 00 00 80 00 83 00 00 81
|
|
# 51
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
|
|
# * - Not a valid ASCII/Unicode value.
|
|
|
|
Keyboard-shift-map:
|
|
00
|
|
# es
|
|
1b
|
|
# ! @ # $ % ^ & * ( ) _ + backspace
|
|
21 40 23 24 25 53 26 2a 28 29 5f 2b 08
|
|
# 0f
|
|
# tab Q W E R T Y U I O P { }
|
|
09 51 57 45 52 54 59 55 49 5f 50 7b 7d
|
|
# 1c
|
|
# enter (newline)
|
|
0a 00
|
|
# 1e
|
|
# A S D F G H J K L : " ~ |
|
|
41 53 44 46 47 48 4a 4b 4c 3a 22 7e 00 7c
|
|
# 2c
|
|
# Z X C V B N M < > ? *
|
|
5a 58 43 56 42 4e 4d 3c 3e 3f 00 2a
|
|
# 38
|
|
# space
|
|
00 20
|
|
# 3a
|
|
00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00
|
|
# 48
|
|
# ↑* ←* →* ↓*
|
|
82 00 00 80 00 83 00 00 81
|
|
# 51
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
|
|
# * - Not a valid ASCII/Unicode value.
|
|
|
|
Keyboard-ctrl-map:
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# 10
|
|
# ^q ^w ^e ^r ^t ^y ^u tb ^o ^p
|
|
11 17 05 12 14 19 15 09 1f 10 00 00
|
|
# 1c
|
|
# carriage-return
|
|
0d 00
|
|
# 1e
|
|
# ^a ^s ^d ^f ^g ^h ^j ^j ^l ^\
|
|
01 13 04 06 07 08 0a 0b 0c 00 00 00 00 1c
|
|
# 2c
|
|
# ^z ^x ^c ^v ^b ^n ^m ^/
|
|
1a 18 03 16 02 0e 0d 00 00 1f 00 00
|
|
# 38
|
|
# space
|
|
00 20
|
|
# 3a
|
|
00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00
|
|
# 48
|
|
# ↑* ←* →* ↓*
|
|
82 00 00 80 00 83 00 00 81
|
|
# 51
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
|
|
# * - Not a valid ASCII/Unicode value.
|
|
# }}}
|
|
|
|
Video-mode-info:
|
|
# video mode info {{{
|
|
0/imm16 # attributes
|
|
00 # winA
|
|
00 # winB
|
|
# 04
|
|
0/imm16 # granularity
|
|
0/imm16 # winsize
|
|
# 08
|
|
0/imm16 # segmentA
|
|
0/imm16 # segmentB
|
|
# 0c
|
|
0/imm32 # realFctPtr (who knows)
|
|
# 10
|
|
0/imm16 # pitch
|
|
0/imm16 # Xres
|
|
0/imm16 # Yres
|
|
0/imm16 # Wchar Ychar
|
|
# 18
|
|
00 # planes
|
|
00 # bpp
|
|
00 # banks
|
|
00 # memory_model
|
|
# 1c
|
|
00 # bank_size
|
|
00 # image_pages
|
|
00 # reserved
|
|
# 1f
|
|
0/imm16 # red_mask red_position
|
|
0/imm16 # green_mask green_position
|
|
0/imm16 # blue_mask blue_position
|
|
0/imm16 # rsv_mask rsv_position
|
|
00 # directcolor_attributes
|
|
# 28
|
|
Video-memory-addr:
|
|
0/imm32 # physbase
|
|
|
|
# 2c
|
|
# reserved for video mode info
|
|
00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# }}}
|
|
|
|
Font:
|
|
# Bitmaps for some ASCII characters (soon Unicode) {{{
|
|
# Part of GNU Unifont
|
|
# 8px wide, 16px tall
|
|
# Based on http://unifoundry.com/pub/unifont/unifont-13.0.05/font-builds/unifont-13.0.05.hex.gz
|
|
# See https://en.wikipedia.org/wiki/GNU_Unifont#The_.hex_font_format
|
|
# Website: http://unifoundry.com/unifont/index.html
|
|
# License: http://unifoundry.com/LICENSE.txt (GPL v2)
|
|
# Each line below is a bitmap for a single character.
|
|
# Each byte is a bitmap for a single row of 8 pixels.
|
|
|
|
# some unprintable ASCII chars
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# 0x20 = space
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# !
|
|
00 00 00 00 08 08 08 08 08 08 08 00 08 08 00 00
|
|
# "
|
|
00 00 22 22 22 22 00 00 00 00 00 00 00 00 00 00
|
|
# 0x23 = '#'
|
|
00 00 00 00 12 12 12 7e 24 24 7e 48 48 48 00 00
|
|
# $
|
|
00 00 00 00 08 3e 49 48 38 0e 09 49 3e 08 00 00
|
|
# %
|
|
00 00 00 00 31 4a 4a 34 08 08 16 29 29 46 00 00
|
|
# &
|
|
00 00 00 00 1c 22 22 14 18 29 45 42 46 39 00 00
|
|
# '
|
|
00 00 08 08 08 08 00 00 00 00 00 00 00 00 00 00
|
|
# (
|
|
00 00 00 04 08 08 10 10 10 10 10 10 08 08 04 00
|
|
# )
|
|
00 00 00 20 10 10 08 08 08 08 08 08 10 10 20 00
|
|
# *
|
|
00 00 00 00 00 00 08 49 2a 1c 2a 49 08 00 00 00
|
|
# +
|
|
00 00 00 00 00 00 08 08 08 7f 08 08 08 00 00 00
|
|
# ,
|
|
00 00 00 00 00 00 00 00 00 00 00 00 18 08 08 10
|
|
# -
|
|
00 00 00 00 00 00 00 00 00 3c 00 00 00 00 00 00
|
|
# .
|
|
00 00 00 00 00 00 00 00 00 00 00 00 18 18 00 00
|
|
# /
|
|
00 00 00 00 02 02 04 08 08 10 10 20 40 40 00 00
|
|
# 0x30 = '0'
|
|
00 00 00 00 18 24 42 46 4a 52 62 42 24 18 00 00
|
|
# 1
|
|
00 00 00 00 08 18 28 08 08 08 08 08 08 3e 00 00
|
|
# 2
|
|
00 00 00 00 3c 42 42 02 0c 10 20 40 40 7e 00 00
|
|
# 3
|
|
00 00 00 00 3c 42 42 02 1c 02 02 42 42 3c 00 00
|
|
# 4
|
|
00 00 00 00 04 0c 14 24 44 44 7e 04 04 04 00 00
|
|
# 5
|
|
00 00 00 00 7e 40 40 40 7c 02 02 02 42 3c 00 00
|
|
# 6
|
|
00 00 00 00 1c 20 40 40 7c 42 42 42 42 3c 00 00
|
|
# 7
|
|
00 00 00 00 7e 02 02 04 04 04 08 08 08 08 00 00
|
|
# 8
|
|
00 00 00 00 3c 42 42 42 3c 42 42 42 42 3c 00 00
|
|
# 9
|
|
00 00 00 00 3c 42 42 42 3e 02 02 02 04 38 00 00
|
|
# :
|
|
00 00 00 00 00 00 18 18 00 00 00 18 18 00 00 00
|
|
# ;
|
|
00 00 00 00 00 00 18 18 00 00 00 18 08 08 10 00
|
|
# <
|
|
00 00 00 00 00 02 04 08 10 20 10 08 04 02 00 00
|
|
# =
|
|
00 00 00 00 00 00 00 7e 00 00 00 7e 00 00 00 00
|
|
# >
|
|
00 00 00 00 00 40 20 10 08 04 08 10 20 40 00 00
|
|
# ?
|
|
00 00 00 00 3c 42 42 02 04 08 08 00 08 08 00 00
|
|
# 0x40 = @
|
|
00 00 00 00 1c 22 4a 56 52 52 52 4e 20 1e 00 00
|
|
# A
|
|
00 00 00 00 18 24 24 42 42 7e 42 42 42 42 00 00
|
|
# B
|
|
00 00 00 00 7c 42 42 42 7c 42 42 42 42 7c 00 00
|
|
# C
|
|
00 00 00 00 3c 42 42 40 40 40 40 42 42 3c 00 00
|
|
# D
|
|
00 00 00 00 78 44 42 42 42 42 42 42 44 78 00 00
|
|
# E
|
|
00 00 00 00 7e 40 40 40 7c 40 40 40 40 7e 00 00
|
|
# F
|
|
00 00 00 00 7e 40 40 40 7c 40 40 40 40 40 00 00
|
|
# G
|
|
00 00 00 00 3c 42 42 40 40 4e 42 42 46 3a 00 00
|
|
# H
|
|
00 00 00 00 42 42 42 42 7e 42 42 42 42 42 00 00
|
|
# I
|
|
00 00 00 00 3e 08 08 08 08 08 08 08 08 3e 00 00
|
|
# J
|
|
00 00 00 00 1f 04 04 04 04 04 04 44 44 38 00 00
|
|
# K
|
|
00 00 00 00 42 44 48 50 60 60 50 48 44 42 00 00
|
|
# L
|
|
00 00 00 00 40 40 40 40 40 40 40 40 40 7e 00 00
|
|
# M
|
|
00 00 00 00 42 42 66 66 5a 5a 42 42 42 42 00 00
|
|
# N
|
|
00 00 00 00 42 62 62 52 52 4a 4a 46 46 42 00 00
|
|
# O
|
|
00 00 00 00 3c 42 42 42 42 42 42 42 42 3c 00 00
|
|
# 0x50 = P
|
|
00 00 00 00 7c 42 42 42 7c 40 40 40 40 40 00 00
|
|
# Q
|
|
00 00 00 00 3c 42 42 42 42 42 42 5a 66 3c 03 00
|
|
# R
|
|
00 00 00 00 7c 42 42 42 7c 48 44 44 42 42 00 00
|
|
# S
|
|
00 00 00 00 3c 42 42 40 30 0c 02 42 42 3c 00 00
|
|
# T
|
|
00 00 00 00 7f 08 08 08 08 08 08 08 08 08 00 00
|
|
# U
|
|
00 00 00 00 42 42 42 42 42 42 42 42 42 3c 00 00
|
|
# V
|
|
00 00 00 00 41 41 41 22 22 22 14 14 08 08 00 00
|
|
# W
|
|
00 00 00 00 42 42 42 42 5a 5a 66 66 42 42 00 00
|
|
# X
|
|
00 00 00 00 42 42 24 24 18 18 24 24 42 42 00 00
|
|
# Y
|
|
00 00 00 00 41 41 22 22 14 08 08 08 08 08 00 00
|
|
# Z
|
|
00 00 00 00 7e 02 02 04 08 10 20 40 40 7e 00 00
|
|
# [
|
|
00 00 00 0e 08 08 08 08 08 08 08 08 08 08 0e 00
|
|
# \
|
|
00 00 00 00 40 40 20 10 10 08 08 04 02 02 00 00
|
|
# ]
|
|
00 00 00 70 10 10 10 10 10 10 10 10 10 10 70 00
|
|
# ^
|
|
00 00 18 24 42 00 00 00 00 00 00 00 00 00 00 00
|
|
# _
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 7f 00
|
|
# 0x60 = backtick
|
|
00 20 10 08 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# a
|
|
00 00 00 00 00 00 3c 42 02 3e 42 42 46 3a 00 00
|
|
# b
|
|
00 00 00 40 40 40 5c 62 42 42 42 42 62 5c 00 00
|
|
# c
|
|
00 00 00 00 00 00 3c 42 40 40 40 40 42 3c 00 00
|
|
# d
|
|
00 00 00 02 02 02 3a 46 42 42 42 42 46 3a 00 00
|
|
# e
|
|
00 00 00 00 00 00 3c 42 42 7e 40 40 42 3c 00 00
|
|
# f
|
|
00 00 00 0c 10 10 10 7c 10 10 10 10 10 10 00 00
|
|
# g
|
|
00 00 00 00 00 02 3a 44 44 44 38 20 3c 42 42 3c
|
|
# h
|
|
00 00 00 40 40 40 5c 62 42 42 42 42 42 42 00 00
|
|
# i
|
|
00 00 00 08 08 00 18 08 08 08 08 08 08 3e 00 00
|
|
# j
|
|
00 00 00 04 04 00 0c 04 04 04 04 04 04 04 48 30
|
|
# k
|
|
00 00 00 40 40 40 44 48 50 60 50 48 44 42 00 00
|
|
# l
|
|
00 00 00 18 08 08 08 08 08 08 08 08 08 3e 00 00
|
|
# m
|
|
00 00 00 00 00 00 76 49 49 49 49 49 49 49 00 00
|
|
# n
|
|
00 00 00 00 00 00 5c 62 42 42 42 42 42 42 00 00
|
|
# o
|
|
00 00 00 00 00 00 3c 42 42 42 42 42 42 3c 00 00
|
|
# 0x70 = p
|
|
00 00 00 00 00 00 5c 62 42 42 42 42 62 5c 40 40
|
|
# q
|
|
00 00 00 00 00 00 3a 46 42 42 42 42 46 3a 02 02
|
|
# r
|
|
00 00 00 00 00 00 5c 62 42 40 40 40 40 40 00 00
|
|
# s
|
|
00 00 00 00 00 00 3c 42 40 30 0c 02 42 3c 00 00
|
|
# t
|
|
00 00 00 00 10 10 10 7c 10 10 10 10 10 0c 00 00
|
|
# u
|
|
00 00 00 00 00 00 42 42 42 42 42 42 46 3a 00 00
|
|
# v
|
|
00 00 00 00 00 00 42 42 42 24 24 24 18 18 00 00
|
|
# w
|
|
00 00 00 00 00 00 41 49 49 49 49 49 49 36 00 00
|
|
# x
|
|
00 00 00 00 00 00 42 42 24 18 18 24 42 42 00 00
|
|
# y
|
|
00 00 00 00 00 00 42 42 42 42 42 26 1a 02 02 3c
|
|
# z
|
|
00 00 00 00 00 00 7e 02 04 08 10 20 40 7e 00 00
|
|
# {
|
|
00 00 00 0c 10 10 08 08 10 20 10 08 08 10 10 0c
|
|
# |
|
|
00 00 08 08 08 08 08 08 08 08 08 08 08 08 08 08
|
|
# }
|
|
00 00 00 30 08 08 10 10 08 04 08 10 10 08 08 30
|
|
# ~
|
|
00 00 00 31 49 46 00 00 00 00 00 00 00 00 00 00
|
|
# 0x7f = del (unused)
|
|
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
|
|
# }}}
|
|
|
|
## Controlling IDE (ATA) hard disks
|
|
# Uses 28-bit PIO mode.
|
|
# Inspired by https://colorforth.github.io/ide.html
|
|
#
|
|
# Resources:
|
|
# https://wiki.osdev.org/ATA_PIO_Mode
|
|
# https://forum.osdev.org/viewtopic.php?f=1&p=167798
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# read-sector, according to https://www.scs.stanford.edu/11wi-cs140/pintos/specs/ata-3-std.pdf
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== data
|
|
|
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# code disk
|
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# All ports are 8-bit except data-port, which is 16-bit.
|
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Primary-bus-primary-drive:
|
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# command-port: int (write)
|
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0x1f7/imm32
|
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# status-port: int (read)
|
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0x1f7/imm32
|
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# alternative-status-port: int (read)
|
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0x3f6/imm32
|
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# error-port: int (read)
|
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0x1f1/imm32
|
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# drive-and-head-port: int
|
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0x1f6/imm32
|
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# sector-count-port: int
|
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0x1f2/imm32
|
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# lba-low-port: int
|
|
0x1f3/imm32
|
|
# lba-mid-port: int
|
|
0x1f4/imm32
|
|
# lba-high-port: int
|
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0x1f5/imm32
|
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# data-port: int
|
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0x1f0/imm32
|
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# drive-code: byte # only drive-specific field
|
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0xe0/imm32 # LBA mode also enabled
|
|
|
|
# data disk
|
|
# All ports are 8-bit except data-port, which is 16-bit.
|
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Primary-bus-secondary-drive:
|
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# command-port: int (write)
|
|
0x1f7/imm32
|
|
# status-port: int (read)
|
|
0x1f7/imm32
|
|
# alternative-status-port: int (read)
|
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0x3f6/imm32
|
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# error-port: int (read)
|
|
0x1f1/imm32
|
|
# drive-and-head-port: int
|
|
0x1f6/imm32
|
|
# sector-count-port: int
|
|
0x1f2/imm32
|
|
# lba-low-port: int
|
|
0x1f3/imm32
|
|
# lba-mid-port: int
|
|
0x1f4/imm32
|
|
# lba-high-port: int
|
|
0x1f5/imm32
|
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# data-port: int
|
|
0x1f0/imm32
|
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# drive-code: byte # only drive-specific field
|
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0xf0/imm32 # LBA mode also enabled
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|
|
|
== code
|
|
|
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load-sectors: # disk: (addr disk), lba: int, n: int, out: (addr stream byte)
|
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# . prologue
|
|
55/push-ebp
|
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89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
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51/push-ecx
|
|
52/push-edx
|
|
# check for drive
|
|
(drive-exists? *(ebp+8)) # => eax
|
|
3d/compare-eax-and 0/imm32/false
|
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0f 84/jump-if-= $load-sectors:end/disp32
|
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# kick off read
|
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(ata-drive-select *(ebp+8) *(ebp+0xc))
|
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(clear-ata-error *(ebp+8))
|
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(ata-sector-count *(ebp+8) *(ebp+0x10))
|
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(ata-lba *(ebp+8) *(ebp+0xc))
|
|
(ata-command *(ebp+8) 0x20) # read sectors with retries
|
|
# for each sector
|
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{
|
|
# poll for results
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "waiting for sector.." 7 0)
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|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "." 7 0)
|
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(while-ata-busy *(ebp+8))
|
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(until-ata-data-available *(ebp+8))
|
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#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "reading\n" 7 0)
|
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# var data-port/edx = disk->data-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
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8b/-> *(eax+0x24) 2/r32/edx
|
|
# emit results
|
|
31/xor %eax 0/r32/eax
|
|
b9/copy-to-ecx 0x200/imm32 # 512 bytes per sector
|
|
{
|
|
81 7/subop/compare %ecx 0/imm32
|
|
74/jump-if-= break/disp8
|
|
66 ed/read-port-dx-into-ax
|
|
# write 2 bytes to stream one at a time
|
|
(append-byte *(ebp+0x14) %eax)
|
|
49/decrement-ecx
|
|
c1/shift 5/subop/right-padding-zeroes %eax 8/imm8
|
|
(append-byte *(ebp+0x14) %eax)
|
|
49/decrement-ecx
|
|
eb/jump loop/disp8
|
|
}
|
|
# next sector
|
|
ff 1/subop/decrement *(ebp+0x10)
|
|
#? (draw-int32-decimal-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0x10) 0xc 0)
|
|
81 7/subop/compare *(ebp+0x10) 0/imm32
|
|
7e/jump-if-<= break/disp8
|
|
(wait-400ns *(ebp+8))
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "next sector\n" 7 0)
|
|
e9/jump loop/disp32
|
|
}
|
|
$load-sectors:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
59/pop-to-ecx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
store-sectors: # disk: (addr disk), lba: int, n: int, in: (addr stream byte)
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
51/push-ecx
|
|
52/push-edx
|
|
53/push-ebx
|
|
# check for drive
|
|
(drive-exists? *(ebp+8)) # => eax
|
|
3d/compare-eax-and 0/imm32/false
|
|
0f 84/jump-if-= $store-sectors:end/disp32
|
|
# kick off write
|
|
(ata-drive-select *(ebp+8) *(ebp+0xc))
|
|
(clear-ata-error *(ebp+8))
|
|
(ata-sector-count *(ebp+8) *(ebp+0x10))
|
|
(ata-lba *(ebp+8) *(ebp+0xc))
|
|
(ata-command *(ebp+8) 0x30) # write sectors with retries
|
|
# for each sector
|
|
#? (set-cursor-position 0 0 0)
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "0" 7 0)
|
|
{
|
|
# wait
|
|
(while-ata-busy *(ebp+8))
|
|
(until-ata-ready-for-data *(ebp+8))
|
|
# var data-port/edx = disk->data-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0x24) 2/r32/edx
|
|
# send data
|
|
b9/copy-to-ecx 0x200/imm32 # 512 bytes per sector
|
|
# . var first-byte/ebx: byte
|
|
# . when it's more than 0xff, we're at an even-numbered byte
|
|
bb/copy-to-ebx 0xffff/imm32
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "D" 7 0)
|
|
$store-sectors:store-sector:
|
|
{
|
|
81 7/subop/compare %ecx 0/imm32
|
|
74/jump-if-= break/disp8
|
|
# this loop is slow, but the ATA spec also requires a small delay
|
|
(stream-empty? *(ebp+0x14)) # => eax
|
|
3d/compare-eax-and 0/imm32/false
|
|
75/jump-if-!= break/disp8
|
|
# read byte from stream
|
|
(read-byte *(ebp+0x14)) # => eax
|
|
# if we're at an odd-numbered byte, save it to first-byte
|
|
81 7/subop/compare %ebx 0xff/imm32
|
|
{
|
|
7e/jump-if-<= break/disp8
|
|
89/<- %ebx 0/r32/eax
|
|
eb/jump $store-sectors:store-sector/disp8
|
|
}
|
|
# otherwise OR it with first-byte and write it out
|
|
c1/shift 4/subop/left %eax 8/imm8
|
|
09/or %eax 3/r32/ebx
|
|
66 ef/write-ax-into-port-dx
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
# reset first-byte
|
|
bb/copy-to-ebx 0xffff/imm32
|
|
eb/jump loop/disp8
|
|
}
|
|
# write out final first-byte if necessary
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "I" 7 0)
|
|
81 7/subop/compare %ebx 0xff/imm32
|
|
{
|
|
7f/jump-if-> break/disp8
|
|
89/<- %eax 3/r32/ebx
|
|
66 ef/write-ax-into-port-dx
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
}
|
|
# pad zeroes
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "P" 7 0)
|
|
31/xor %eax 0/r32/eax
|
|
{
|
|
81 7/subop/compare %ecx 0/imm32
|
|
74/jump-if-= break/disp8
|
|
66 ef/write-ax-into-port-dx
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
eb/jump loop/disp8
|
|
}
|
|
# next sector
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "N" 7 0)
|
|
ff 1/subop/decrement *(ebp+0x10)
|
|
81 7/subop/compare *(ebp+0x10) 0/imm32
|
|
7e/jump-if-<= break/disp8
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "W" 7 0)
|
|
(wait-400ns *(ebp+8))
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "L" 7 0)
|
|
e9/jump loop/disp32
|
|
}
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "F" 7 0)
|
|
(flush-ata-cache *(ebp+8))
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "Y" 7 0)
|
|
$store-sectors:end:
|
|
# . restore registers
|
|
5b/pop-to-ebx
|
|
5a/pop-to-edx
|
|
59/pop-to-ecx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
# disk helpers {{{
|
|
|
|
drive-exists?: # disk: (addr disk) -> _/eax: boolean
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
52/push-edx
|
|
# check for floating bus
|
|
{
|
|
31/xor %eax 0/r32/eax
|
|
ba/copy-to-edx 0x1f7/imm32
|
|
ec/read-port-dx-into-al
|
|
3d/compare-eax-and 0xff/imm32
|
|
# if eax is 0xff, primary bus has no drives
|
|
b8/copy-to-eax 0/imm32/false
|
|
0f 84/jump-if-= $drive-exists?:end/disp32
|
|
}
|
|
# identify
|
|
(ata-drive-select *(ebp+8) 0)
|
|
(ata-sector-count *(ebp+8) 0)
|
|
(ata-lba *(ebp+8) 0)
|
|
(ata-command *(ebp+8) 0xec) # identify
|
|
# var status-port/edx = disk->status-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+4) 2/r32/edx # 4 = status-port offset
|
|
# read status port
|
|
# TODO: might need to spin here for 400ns: https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#400ns_delays
|
|
31/xor %eax 0/r32/eax
|
|
ec/read-port-dx-into-al
|
|
# if eax is 0, drive does not exist
|
|
3d/compare-eax-and 0/imm32
|
|
{
|
|
74/jump-if-= break/disp8
|
|
b8/copy-to-eax 1/imm32/true
|
|
eb/jump $drive-exists?:complete-identify/disp8
|
|
}
|
|
# TODO: might need to perform remaining steps at https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#IDENTIFY_command
|
|
b8/copy-to-eax 0/imm32/false
|
|
$drive-exists?:complete-identify:
|
|
50/push-eax
|
|
# var data-port/edx = disk->data-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0x24) 2/r32/edx # 0x24 = data-port offset
|
|
# clear FIFO from the drive
|
|
b9/copy-to-ecx 0x200/imm32
|
|
{
|
|
81 7/subop/compare %ecx 0/imm32
|
|
74/jump-if-= break/disp8
|
|
# read 4 bytes
|
|
ed/read-port-dx-into-eax
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
49/decrement-ecx
|
|
eb/jump loop/disp8
|
|
}
|
|
58/pop-to-eax
|
|
$drive-exists?:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
ata-drive-select: # disk: (addr disk), lba: int
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
56/push-esi
|
|
# esi = disk
|
|
8b/-> *(ebp+8) 6/r32/esi
|
|
# var drive-head/edx: byte = lba >> 24
|
|
8b/-> *(ebp+0xc) 2/r32/edx
|
|
c1/shift 5/subop/right-padding-zeroes %edx 0x18/imm8
|
|
# var drive-code/eax: byte = disk->drive-code | drive-head
|
|
8b/-> *(esi+0x28) 0/r32/eax # 0x28 = drive-code offset
|
|
09/or= %eax 2/r32/edx
|
|
# var drive-and-head-port/edx: int
|
|
8b/-> *(esi+0x10) 2/r32/edx # 0x10 = drive-and-head-port offset
|
|
ee/write-al-into-port-dx
|
|
$ata-drive-select:end:
|
|
# . restore registers
|
|
5e/pop-to-esi
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
clear-ata-error: # disk: (addr disk)
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var error-port/edx = disk->error-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0xc) 2/r32/edx # 0xc = error-port offset
|
|
#
|
|
b8/copy-to-eax 0/imm32
|
|
ee/write-al-into-port-dx
|
|
$ata-error:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
ata-sector-count: # disk: (addr disk), n: byte
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var sector-count-port/edx = disk->sector-count-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0x14) 2/r32/edx # 0x14 = sector-count-port offset
|
|
#
|
|
8b/-> *(ebp+0xc) 0/r32/eax
|
|
ee/write-al-into-port-dx
|
|
$ata-sector-count:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
ata-lba: # disk: (addr disk), lba: int
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var port/edx = disk->port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0x18) 2/r32/edx # 0x18 = lba-low-port offset
|
|
# eax = lba
|
|
8b/-> *(ebp+0xc) 0/r32/eax
|
|
# lo
|
|
ee/write-al-into-port-dx
|
|
# mid
|
|
42/increment-dx # lba-mid-port
|
|
c1/shift 5/subop/right-padding-zeroes %eax 8/imm8
|
|
ee/write-al-into-port-dx
|
|
# hi
|
|
42/increment-dx # lba-high-port
|
|
c1/shift 5/subop/right-padding-zeroes %eax 8/imm8
|
|
ee/write-al-into-port-dx
|
|
$ata-lba:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
ata-command: # disk: (addr disk), cmd: byte
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var command-port/edx = disk->command-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+0) 2/r32/edx # 0 = command-port offset
|
|
#
|
|
8b/-> *(ebp+0xc) 0/r32/eax
|
|
ee/write-al-into-port-dx
|
|
$ata-command:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
while-ata-busy: # disk: (addr disk)
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var status-port/edx = disk->status-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+4) 2/r32/edx # 4 = status-port offset
|
|
{
|
|
ec/read-port-dx-into-al
|
|
a8/test-bits-in-al 0x80/imm8/bsy # set zf if bit 7 (most significant) is not set
|
|
75/jump-if-zf-not-set-and-bit-7-set loop/disp8
|
|
}
|
|
$while-ata-busy:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
c3/return
|
|
|
|
until-ata-data-available: # disk: (addr disk)
|
|
# . save registers
|
|
50/push-eax
|
|
52/push-edx
|
|
# var status-port/edx = disk->status-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+4) 2/r32/edx # 4 = status-port offset
|
|
{
|
|
ec/read-port-dx-into-al
|
|
a8/test-bits-in-al 8/imm8/drq # set zf if bit 3 is not set
|
|
74/jump-if-zf-set-and-bit-3-not-set loop/disp8
|
|
}
|
|
$until-ata-data-available:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
c3/return
|
|
|
|
until-ata-ready-for-data:
|
|
(until-ata-data-available)
|
|
c3/return
|
|
|
|
# https://wiki.osdev.org/index.php?title=ATA_PIO_Mode&oldid=25664#400ns_delays
|
|
wait-400ns: # disk: (addr disk)
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
51/push-ecx
|
|
52/push-edx
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "waiting 400ns\n" 7 0)
|
|
# var status-port/edx = disk->status-port
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
8b/-> *(eax+4) 2/r32/edx # 4 = status-port offset
|
|
#
|
|
b9/copy-to-ecx 0x10/imm32
|
|
{
|
|
81 7/subop/compare %ecx 0/imm32
|
|
74/jump-if-= break/disp8
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "." 7 0)
|
|
ec/read-port-dx-into-al
|
|
49/decrement-ecx
|
|
eb/jump loop/disp8
|
|
}
|
|
$wait-400ns:end:
|
|
# . restore registers
|
|
5a/pop-to-edx
|
|
59/pop-to-ecx
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
# Flush cache isn't in ATA 3, but it shows up by the ATA 5 spec:
|
|
# http://hddguru.com/download/documentation/ATA-ATAPI-standard-5/ATA-ATAPI-5.pdf
|
|
flush-ata-cache: # disk: (addr disk)
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
#
|
|
(ata-drive-select *(ebp+8) 0)
|
|
(ata-command *(ebp+8) 0xe7) # flush cache
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "W" 7 0)
|
|
(while-ata-busy *(ebp+8))
|
|
#? (draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "X" 7 0)
|
|
# TODO: seems unneeded? works for a single sector but Qemu hangs with multiple
|
|
# sectors. Data is still written.
|
|
#? (until-ata-ready-for-data *(ebp+8))
|
|
$flush-ata-cache:end:
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
# }}}
|
|
|
|
## Controlling a PS/2 mouse
|
|
# Uses no IRQs, just polling.
|
|
# Thanks Dave Long: https://github.com/jtauber/cleese/blob/master/necco/kernel/bochs/py8042.py
|
|
#
|
|
# Resources:
|
|
# https://wiki.osdev.org/Mouse_Input
|
|
|
|
# results x/eax, y/ecx range from -256 to +255
|
|
# See https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Format_of_First_3_Packet_Bytes
|
|
read-mouse-event: # -> _/eax: int, _/ecx: int
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
52/push-edx
|
|
53/push-ebx
|
|
# if no event, return 0, 0
|
|
b8/copy-to-eax 0/imm32
|
|
b9/copy-to-ecx 0/imm32
|
|
(any-mouse-event?) # => eax
|
|
3d/compare-eax-and 0/imm32/false
|
|
74/jump-if-= $read-mouse-event:end/disp8
|
|
# var f1/edx: byte = inb(0x60)
|
|
31/xor %eax 0/r32/eax
|
|
e4/read-port-into-al 0x60/imm8
|
|
89/<- %edx 0/r32/eax
|
|
(wait-for-mouse-event)
|
|
# var dx/ebx: byte = inb(0x60)
|
|
31/xor %eax 0/r32/eax
|
|
e4/read-port-into-al 0x60/imm8
|
|
89/<- %ebx 0/r32/eax
|
|
(wait-for-mouse-event)
|
|
# var dy/ecx: byte = inb(0x60)
|
|
31/xor %eax 0/r32/eax
|
|
e4/read-port-into-al 0x60/imm8
|
|
89/<- %ecx 0/r32/eax
|
|
# eax = dx
|
|
89/<- %eax 3/r32/ebx
|
|
# if (f1 & 0x10) dx = -dx
|
|
{
|
|
f6 0/subop/test-bits %dl 0x10/imm8
|
|
74/jump-if-zero break/disp8
|
|
0d/or-eax-with 0xffffff00/imm32
|
|
}
|
|
# if (f1 & 0x20) dy = -dy
|
|
{
|
|
f6 0/subop/test-bits %dl 0x20/imm8
|
|
74/jump-if-zero break/disp8
|
|
81 1/subop/or %ecx 0xffffff00/imm32
|
|
}
|
|
$read-mouse-event:end:
|
|
# . restore registers
|
|
5b/pop-to-ebx
|
|
5a/pop-to-edx
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
# mouse helpers {{{
|
|
|
|
wait-for-mouse-event:
|
|
# . save registers
|
|
50/push-eax
|
|
#
|
|
{
|
|
(any-mouse-event?) # => eax
|
|
3d/compare-eax-and 0/imm32/false
|
|
74/jump-if-= loop/disp8
|
|
}
|
|
$wait-for-mouse-event:end:
|
|
# . restore registers
|
|
58/pop-to-eax
|
|
# .
|
|
c3/return
|
|
|
|
any-mouse-event?: # -> _/eax: boolean
|
|
31/xor %eax 0/r32/eax
|
|
# 0x1 bit: there's data from the keyboard controller
|
|
# 0x20 bit: it's data from the aux port (the mouse)
|
|
e4/read-port-into-al 0x60/imm8
|
|
24/and-al-with 0x21/imm8
|
|
3c/compare-al-with 0x21/imm8
|
|
0f 94/set-byte-if-= %al
|
|
c3/return
|
|
|
|
initialize-mouse:
|
|
(enable-keyboard-controller-aux-device)
|
|
# tell mouse to use default settings
|
|
(send-mouse-command 0xf6)
|
|
# enable mouse
|
|
(send-mouse-command 0xf4)
|
|
c3/return
|
|
|
|
enable-keyboard-controller-aux-device:
|
|
(command-keyboard-controller 0xa8)
|
|
c3/return
|
|
|
|
send-mouse-command: # command: byte
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
#
|
|
(command-keyboard-controller 0xd4)
|
|
(send-keyboard-controller-data *(ebp+8))
|
|
(wait-for-ack-from-mouse)
|
|
$send-mouse-command:end:
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
wait-for-ack-from-mouse:
|
|
# . save registers
|
|
50/push-eax
|
|
{
|
|
(read-keyboard-controller-data) # => eax
|
|
3d/compare-eax-with 0xfa/imm32
|
|
75/jump-if-!= loop/disp8
|
|
}
|
|
$wait-for-ack-from-mouse:end:
|
|
# . restore registers
|
|
58/pop-eax
|
|
c3/return
|
|
|
|
command-keyboard-controller: # command: byte
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
#
|
|
(poll-keyboard-controller-to-write)
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
e6/write-al-into-port 0x64/imm8
|
|
$command-keyboard-controller:end:
|
|
# . restore registers
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
send-keyboard-controller-data: # data: byte
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
#
|
|
(poll-keyboard-controller-to-write)
|
|
8b/-> *(ebp+8) 0/r32/eax
|
|
e6/write-al-into-port 0x60/imm8
|
|
$send-keyboard-controller-data:end:
|
|
# . restore registers
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
read-keyboard-controller-data: # -> _/eax: byte
|
|
(poll-keyboard-controller-to-read-data-port)
|
|
31/xor %eax 0/r32/eax
|
|
e4/read-port-into-al 0x60/imm8
|
|
c3/return
|
|
|
|
poll-keyboard-controller-to-write:
|
|
# . save registers
|
|
50/push-eax
|
|
# "All output to port 0x60 or 0x64 must be preceded by waiting for bit 1
|
|
# (value=2) of port 0x64 to become clear."
|
|
# https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Waiting_to_Send_Bytes_to_Port_0x60_and_0x64
|
|
{
|
|
e4/read-port-into-al 0x64/imm8
|
|
a8/test-bits-in-al 2/imm8 # set zf if bit 1 (second-least significant) is not set
|
|
75/jump-if-zf-not-set-and-bit-1-set loop/disp8
|
|
}
|
|
$poll-keyboard-controller-to-write:end:
|
|
# . restore registers
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
c3/return
|
|
|
|
poll-keyboard-controller-to-read-data-port:
|
|
# . prologue
|
|
55/push-ebp
|
|
89/<- %ebp 4/r32/esp
|
|
# . save registers
|
|
50/push-eax
|
|
# "Bytes cannot be read from port 0x60 until bit 0 (value=1) of port 0x64 is set."
|
|
# https://wiki.osdev.org/index.php?title=Mouse_Input&oldid=25663#Waiting_to_Send_Bytes_to_Port_0x60_and_0x64
|
|
{
|
|
e4/read-port-into-al 0x64/imm8
|
|
a8/test-bits-in-al 1/imm8 # set zf if bit 0 (least significant) is not set
|
|
74/jump-if-zf-set-and-bit-0-not-set loop/disp8
|
|
}
|
|
$poll-keyboard-controller-to-read-data-port:end:
|
|
# . restore registers
|
|
58/pop-to-eax
|
|
# . epilogue
|
|
89/<- %esp 5/r32/ebp
|
|
5d/pop-to-ebp
|
|
c3/return
|
|
|
|
# }}}
|
|
|
|
# vim:ft=subx
|