fba2146593
Both LBA and CHS coordinates are now working for the primary disk on the
primary bus.
Failure modes I ran into:
- ATA ports are 16-bit values. Using instructions with 8-bit immediates
will yield strange results. (I had to debug this twice because I missed
poll-ata-primary-bus-primary-drive-regular-status-word the first time
around.)
Mu's toolchain has been found out here. bootstrap has good
errors but doesn't support the instructions I need in boot.subx. The
self-hosted phases support the instructions but provide no error-checking.
Might be worth starting to add error-checking as I encounter the need.
In this case, a vote for validating metadata sizes even if we don't
validate that instructions pass in the right metadata sizes.
- Can't poll readiness first thing. Maybe we need to always select the
drive first.
- Reading 8-bit values from a 16-bit port (data port 0x1f0) returns garbage.
Reading 32-bit values however works totally fine; go figure. (Maybe
it won't work on real hardware?)
https://forum.osdev.org/viewtopic.php?t=36415
- Passing in a 0 segment will never return data.
17 lines
534 B
Plaintext
17 lines
534 B
Plaintext
# Configuration for the Bochs x86 CPU emulator to run baremetal Mu programs
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# See boot.subx for more details.
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#
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# Installing Bochs:
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# On Mac OS:
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# brew install bochs
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# On Ubuntu Linux 20.04:
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# sudo apt install bochs bochs-sdl bochsbios vgabios
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display_library: sdl2
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#ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
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ata0-master: type=disk, path="disk.img", mode=flat, cylinders=20, heads=16, spt=63 # 10MB, 512 bytes per sector
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boot: disk
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# PS/2 mouse requires black magic that I don't know how to explain.
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log: -
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