From e0455160142fcbf6ded0a0f4e7d4f9d65b883daf Mon Sep 17 00:00:00 2001 From: "Kartik K. Agaram" Date: Mon, 15 Mar 2021 00:05:14 -0700 Subject: . --- boot.subx | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/boot.subx b/boot.subx index 4f6e485b..5df5c805 100644 --- a/boot.subx +++ b/boot.subx @@ -55,17 +55,17 @@ # initialize segment registers b8/copy-to-ax 0/imm16 - 8e/seg-> 3/mod/direct 0/rm32/ax 3/rm32/ds - 8e/seg-> 3/mod/direct 0/rm32/ax 0/rm32/es - 8e/seg-> 3/mod/direct 0/rm32/ax 4/rm32/fs - 8e/seg-> 3/mod/direct 0/rm32/ax 5/rm32/gs + 8e/->seg 3/mod/direct 0/rm32/ax 3/rm32/ds + 8e/->seg 3/mod/direct 0/rm32/ax 0/rm32/es + 8e/->seg 3/mod/direct 0/rm32/ax 4/rm32/fs + 8e/->seg 3/mod/direct 0/rm32/ax 5/rm32/gs # initialize stack to 0x00070000 # We don't read or write the stack before we get to 32-bit mode, but BIOS # calls do. We need to move the stack in case BIOS initializes it to some # low address that we want to write code into. b8/copy-to-ax 0x7000/imm16 - 8e/seg-> 3/mod/direct 0/rm32/ax 2/rm32/ss + 8e/->seg 3/mod/direct 0/rm32/ax 2/rm32/ss bc/copy-to-esp 0/imm16 # undo the A20 hack: https://en.wikipedia.org/wiki/A20_line @@ -94,7 +94,7 @@ b0/copy-to-al 0x7d/imm8 # number of sectors to read = 2*63 - 1 = 125 # address to write sectors to = es:bx = 0x7e00, contiguous with boot segment bb/copy-to-bx 0/imm16 - 8e/seg-> 3/mod/direct 3/rm32/bx 0/r32/es + 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es bb/copy-to-bx 0x7e00/imm16 cd/syscall 0x13/imm8/bios-disk-services 0f 82/jump-if-carry disk_error/disp16 @@ -108,7 +108,7 @@ b0/copy-to-al 0x7e/imm8 # number of sectors to read = 2*63 = 126 # address to write sectors to = es:bx = 0x17800, contiguous with boot segment bb/copy-to-bx 0x1780/imm16 - 8e/seg-> 3/mod/direct 3/rm32/bx 0/r32/es + 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es bb/copy-to-bx 0/imm16 cd/syscall 0x13/imm8/bios-disk-services 0f 82/jump-if-carry disk_error/disp16 @@ -122,14 +122,14 @@ b0/copy-to-al 0x7e/imm8 # number of sectors to read = 2*63 = 126 # address to write sectors to = es:bx = 0x27400, contiguous with boot segment bb/copy-to-bx 0x2740/imm16 - 8e/seg-> 3/mod/direct 3/rm32/bx 0/r32/es + 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es bb/copy-to-bx 0/imm16 cd/syscall 0x13/imm8/bios-disk-services 0f 82/jump-if-carry disk_error/disp16 # reset es bb/copy-to-bx 0/imm16 - 8e/seg-> 3/mod/direct 3/rm32/bx 0/r32/es + 8e/->seg 3/mod/direct 3/rm32/bx 0/r32/es # adjust video mode b4/copy-to-ah 0x4f/imm8 # VBE commands @@ -184,7 +184,7 @@ disk_error: # print 'D' to top-left of screen to indicate disk error # *0xb8000 <- 0x0f44 bb/copy-to-bx 0xb800/imm16 - 8e/seg-> 3/mod/direct 3/rm32/bx 3/r32/ds + 8e/->seg 3/mod/direct 3/rm32/bx 3/r32/ds b0/copy-to-al 0x44/imm8/D b4/copy-to-ah 0x0f/imm8/white-on-black bb/copy-to-bx 0/imm16 @@ -230,11 +230,11 @@ initialize_32bit_mode: # TODO: SubX doesn't understand 66 prefix 66 b8 10 00 # ax <- offset 16 from gdt_start == code - 8e/seg-> 3/mod/direct 0/rm32/ax 3/r32/ds - 8e/seg-> 3/mod/direct 0/rm32/ax 2/r32/ss - 8e/seg-> 3/mod/direct 0/rm32/ax 0/r32/es - 8e/seg-> 3/mod/direct 0/rm32/ax 4/r32/fs - 8e/seg-> 3/mod/direct 0/rm32/ax 5/r32/gs + 8e/->seg 3/mod/direct 0/rm32/ax 3/r32/ds + 8e/->seg 3/mod/direct 0/rm32/ax 2/r32/ss + 8e/->seg 3/mod/direct 0/rm32/ax 0/r32/es + 8e/->seg 3/mod/direct 0/rm32/ax 4/r32/fs + 8e/->seg 3/mod/direct 0/rm32/ax 5/r32/gs bc/copy-to-esp 0x00070000/imm32 -- cgit 1.4.1-2-gfad0