Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.
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328 lines
9.2 KiB

# Dump a stack trace when you abort.
== code
abort: # e: (addr array byte)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
(set-cursor-position-on-real-screen 0 0)
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+8) 0xf 0xc) # 0/real-screen, 0xf/fg=white, 0xc/bg=red
(dump-call-stack)
# crash
{
eb/jump loop/disp8
}
# Helpers below this point are not intended to be reused; they assume the
# program will soon crash. In particular, they destroy the heap.
dump-call-stack:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
53/push-ebx
# var labels/edx: (addr stream {start-address, label-slice} 0x5000)
# start addresses are in ascending order
81 5/subop/subtract %esp 0x3c000/imm32 # 0x5000 labels * 12 bytes per label
68/push 0x3c000/imm32
68/push 0/imm32/read
68/push 0/imm32/write
89/<- %edx 4/r32/esp
#
(load-debug-symbols %edx) # destroys the heap
# traverse the linked list of ebp pointers: https://wiki.osdev.org/Stack_Trace
8b/-> *ebp 3/r32/ebx
{
# loop termination check
81 7/subop/compare %ebx 0/imm32
0f 84/jump-if-= break/disp32
# loop body
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "\n" 0 0xc)
(draw-int32-hex-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebx+4) 0xf 0xc)
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 " " 0 0xc)
(containing-function %edx *(ebx+4)) # => eax, ecx
(draw-slice-wrapping-right-then-down-from-cursor-over-full-screen 0 %eax %ecx 0 0xc)
# loop update
8b/-> *ebx 3/r32/ebx
#
e9/jump loop/disp32
}
$dump-call-stack:end:
# . reclaim locals
81 0/subop/add %esp 0x100c/imm32
# . 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
load-debug-symbols: # labels: (addr stream {start-address, label-slice})
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
53/push-ebx
# create space for a stream on the heap, clobbering any existing data
# var s/ecx: (addr stream byte)
b9/copy-to-ecx 0x03000000/imm32
c7 0/subop/copy *ecx 0/imm32 # write index
c7 0/subop/copy *(ecx+4) 0/imm32 # read index
c7 0/subop/copy *(ecx+8) 0x01000000/imm32 # stream capacity = 16MB
# load sectors starting from sector 10080 = 0x2760
(load-sectors Primary-bus-primary-drive 0x2760 0x800 %ecx) # 0x800 sectors = 1MB
# - parse pointers to portions of this stream into labels
# var curr/ecx: (addr byte) = s->data
81 0/subop/add %ecx 0xc/imm32
{
# loop termination check
b8/copy-to-eax 0/imm32
8a/byte-> *ecx 0/r32/eax
3d/compare-eax-and 0/imm32
0f 84/jump-if-= break/disp32
# loop body
(skip-to-next-space %ecx) # => edx
42/increment-edx
(skip-to-next-newline %edx) # => ebx
(parse-hex-int-helper %edx %ebx) # => eax
43/increment-ebx
(label-append *(ebp+8) %eax %ecx %edx)
# loop update
89/<- %ecx 3/r32/ebx
#
e9/jump loop/disp32
}
$load-debug-symbols: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
skip-to-next-space: # curr: (addr byte) -> _/edx: (addr byte)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
# eax = 0
b8/copy-to-eax 0/imm32
#
8b/-> *(ebp+8) 2/r32/edx
{
8a/byte-> *edx 0/r32/eax
3d/compare-eax-and 0x20/imm32/space
0f 84/jump-if-= break/disp32
3d/compare-eax-and 0/imm32
{
75/jump-if-!= break/disp8
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "done loading" 7 0)
{
eb/jump loop/disp8
}
}
3d/compare-eax-and 0xa/imm32/newline
{
75/jump-if-!= break/disp8
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "unexpected newline" 7 0)
{
eb/jump loop/disp8
}
}
42/increment-edx
e9/jump loop/disp32
}
$skip-to-next-space:end:
# . restore registers
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
skip-to-next-newline: # curr: (addr byte) -> _/ebx: (addr byte)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
# eax = 0
b8/copy-to-eax 0/imm32
#
8b/-> *(ebp+8) 3/r32/ebx
{
8a/byte-> *ebx 0/r32/eax
3d/compare-eax-and 0xa/imm32/newline
0f 84/jump-if-= break/disp32
3d/compare-eax-and 0/imm32
{
75/jump-if-!= break/disp8
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "done loading" 7 0)
{
eb/jump loop/disp8
}
}
3d/compare-eax-and 0x20/imm32/space
{
75/jump-if-!= break/disp8
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "unexpected space" 7 0)
{
eb/jump loop/disp8
}
}
43/increment-ebx
e9/jump loop/disp32
}
$skip-to-next-newline:end:
# . restore registers
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
label-append: # labels: (addr stream {start-address, label-slice}), address: int, start: int, end: int
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
56/push-esi
# esi = labels
8b/-> *(ebp+8) 6/r32/esi
# ecx = labels->write
8b/-> *esi 1/r32/ecx
# labels->data[labels->write] = address
8b/-> *(ebp+0xc) 0/r32/eax
89/<- *(esi+ecx+0xc) 0/r32/eax
# labels->data[labels->write+4] = start
8b/-> *(ebp+0x10) 0/r32/eax
89/<- *(esi+ecx+0x10) 0/r32/eax
# labels->data[labels->write+8] = end
8b/-> *(ebp+0x14) 0/r32/eax
89/<- *(esi+ecx+0x14) 0/r32/eax
# labels->write += 12
81 0/subop/add *esi 0xc/imm32
$label-append:end:
# . restore registers
5e/pop-to-esi
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
containing-function: # labels: (addr stream {start-address, label-slice}), address: int -> start/eax: (addr byte), end/ecx: (addr byte)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
52/push-edx
53/push-ebx
56/push-esi
# esi = labels
8b/-> *(ebp+8) 6/r32/esi
# var curr/ecx: (addr byte) = labels->data
8d/copy-address *(esi+0xc) 1/r32/ecx
# var max/edx: (addr byte) = labels->data + labels->write
8b/-> *esi 2/r32/edx
01/add-to %edx 1/r32/ecx
# var previous-function-name/ebx: (addr slice) = 0
bb/copy-to-ebx 0/imm32
{
# abort if not found
39/compare %ecx 2/r32/edx
{
0f 82/jump-if-addr< break/disp32
(draw-text-wrapping-right-then-down-from-cursor-over-full-screen 0 "failed to find function for address " 7 0)
(draw-int32-hex-wrapping-right-then-down-from-cursor-over-full-screen 0 *(ebp+0xc) 7 0)
{
eb/jump loop/disp8
}
}
# if *curr > address, break
8b/-> *ecx 0/r32/eax
3b/compare 0/r32/eax *(ebp+0xc)
0f 87/jump-if-addr> break/disp32
# if **(curr+4) not '$' or '@', save curr to previous-function-name
{
8b/-> *(ecx+4) 0/r32/eax
8a/byte-> *eax 0/r32/eax
25/and-with-eax 0xff/imm32
3d/compare-eax-and 0x24/imm32/$
74/jump-if-= break/disp8
3d/compare-eax-and 0x40/imm32/@
74/jump-if-= break/disp8
8d/copy-address *(ecx+4) 3/r32/ebx
}
# loop update
81 0/subop/add %ecx 0xc/imm32
#
e9/jump loop/disp32
}
8b/-> *ebx 0/r32/eax
8b/-> *(ebx+4) 1/r32/ecx
$containing-function:end:
# . restore registers
5e/pop-to-esi
5b/pop-to-ebx
5a/pop-to-edx
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
# unlike variants in .mu files, this only supports ASCII
draw-slice-wrapping-right-then-down-from-cursor-over-full-screen: # screen: (addr screen), start: (addr byte), end: (addr byte), color: int, background-color: int
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
# var curr/ecx: (addr byte) = start
8b/-> *(ebp+0xc) 1/r32/ecx
# edx = end
8b/-> *(ebp+0x10) 2/r32/edx
# eax = 0
b8/copy-to-eax 0/imm32
{
# if (curr >= end) break
39/compare %ecx 2/r32/edx
73/jump-if-addr>= break/disp8
# print *curr
8a/byte-> *ecx 0/r32/eax
(draw-code-point-at-cursor-over-full-screen *(ebp+8) %eax *(ebp+0x14) *(ebp+0x18))
#
41/increment-ecx
#
eb/jump loop/disp8
}
$draw-slice-wrapping-right-then-down-from-cursor-over-full-screen: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