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# Test out the video mode by filling in the screen with pixels.
#
# To run, first prepare a realistically sized disk image:
# dd if=/dev/zero of=disk.img count=20160 # 512-byte sectors, so 10MB
# Load the disk image:
# cat baremetal/boot.hex baremetal/ex2.hex |./bootstrap run apps/hex > a.bin
# dd if=a.bin of=disk.img conv=notrunc
# To run:
# qemu-system-i386 disk.img
# Or:
# bochs -f apps/boot.bochsrc # boot.bochsrc loads disk.img
# main: (address 0x8800)
# ecx <- LFB
8b # copy *rm32 to r32
0d # 00/mod/indirect 001/r32/ecx 101/rm32/use-disp32
68 7d 00 00 # disp32
# eax <- LFB + 0xbffff (1024*768 - 1)
8d # copy-address rm32 to r32
81 # 10/mod/*+disp32 000/r32/eax 001/rm32/ecx
ff ff 0b 00 # disp32
# $loop:
# if (eax < ecx) break
39 # compare rm32 with r32
c8 # 11/mod/direct 001/r32/ecx 000/rm32/eax
7c 06 # break if <
# *eax <- 0xff
c6 # copy imm8 to m8 at r32
00 # 00/mod/indirect 000/subop 000/eax
31 # imm32
48 # decrement eax
eb f6 # loop to -10 bytes
# $break:
e9 fb ff ff ff # hang indefinitely
# vim:ft=subx
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