36 lines
770 B
Plaintext
36 lines
770 B
Plaintext
# Test out the video mode by filling in the screen with pixels.
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#
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# To build a disk image:
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# ./translate_subx_baremetal baremetal/ex2.subx # emits disk.img
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# To run:
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# qemu-system-i386 disk.img
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# Or:
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# bochs -f baremetal/boot.bochsrc # boot.bochsrc loads disk.img
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#
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# Expected output:
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# html/baremetal.png
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== code
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main:
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# ecx <- start of video memory
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8b/-> *0x8128 1/r32/ecx
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# eax <- final pixel of video memory
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8d/copy-address *(ecx + 0x0bffff) 0/r32/eax # 0xbffff = 1024*768 - 1
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# for each pixel in video memory
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{
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39/compare %eax 1/r32/ecx
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7c/jump-if-< break/disp8
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# write its column number to it
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88/byte<- *eax 0/r32/AL
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48/decrement-eax
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eb/jump loop/disp8
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}
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# hang indefinitely
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{
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eb/jump loop/disp8
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}
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