diff options
Diffstat (limited to 'baremetal')
| -rw-r--r-- | baremetal/boot.hex | 36 | ||||
| -rw-r--r-- | baremetal/boot0.hex | 16 |
2 files changed, 20 insertions, 32 deletions
diff --git a/baremetal/boot.hex b/baremetal/boot.hex index 08f89fe5..b2156838 100644 --- a/baremetal/boot.hex +++ b/baremetal/boot.hex @@ -299,14 +299,12 @@ e9 fd ff # loop forever # acknowledge interrupt b0 20 # al <- 0x20 e6 20 # port 0x20 <- al - # read status into eax 31 c0 # eax <- xor eax; 11/direct 000/r32/eax 000/rm32/eax + # check output buffer of 8042 keyboard controller (https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html) e4 64 # al <- port 0x64 - # if (status & 0x1) == 0, return - 24 01 # al <- and 0x1 - 3c 00 # compare al, 0 - 74 89 # jump to epilogue if = [label] -# 220: + a8 01 # set zf if bit 0 (least significant) is not set + 74 89 # jump to epilogue if 0 bit is not set [label] +# 21e: # - if keyboard buffer is full, return 31 c9 # ecx <- xor ecx; 11/direct 001/r32/ecx 001/rm32/ecx # var index/ecx: byte @@ -319,33 +317,29 @@ e9 fd ff # loop forever 30 80 00 00 # disp32 [label] # if (al != 0) return 3c 00 # compare al, 0 -# 230: 75 77 # jump to epilogue if != [label] +# 230: # - read keycode e4 60 # al <- port 0x60 -# 234: # - key released # if (al == 0xaa) shift = false # left shift is being lifted 3c aa # compare al, 0xaa 75 0a # jump to $1 if != [label] -# 238: # *shift = 0 c7 # copy imm32 to rm32 05 # 00/mod/indirect 000/subop/copy 101/rm32/use-disp32 10 80 00 00 # disp32 [label] 00 00 00 00 # imm32 -# 242: +# 240: # $1: # if (al == 0xb6) shift = false # right shift is being lifted 3c b6 # compare al, 0xb6 -# 244: 75 0a # jump to $1 if != [label] # *shift = 0 c7 # copy imm32 to rm32 05 # 00/mod/indirect 000/subop/copy 101/rm32/use-disp32 10 80 00 00 # disp32 [label] 00 00 00 00 # imm32 -# 250: # $2: # if (al & 0x80) a key is being lifted; return 50 # push eax @@ -353,7 +347,7 @@ e9 fd ff # loop forever 3c 00 # compare al, 0 58 # pop to eax (without touching flags) 75 51 # jump to epilogue if != [label] -# 258: +# 256: # - key pressed # if (al == 0x2a) shift = true, return # left shift pressed 3c 2a # compare al, 0x2a @@ -364,7 +358,7 @@ e9 fd ff # loop forever 10 80 00 00 # disp32 [label] 01 00 00 00 # imm32 eb 41 # jump to epilogue [label] -# 268: +# 266: # $3: # if (al == 0x36) shift = true, return # right shift pressed 3c 36 # compare al, 0x36 @@ -375,8 +369,8 @@ e9 fd ff # loop forever 10 80 00 00 # disp32 [label] 01 00 00 00 # imm32 eb 31 # jump to epilogue [label] +# 276: # $4: -# 278: # - convert key to character # if (shift) use keyboard normal map 81 # operate on rm32 and imm32 @@ -384,35 +378,31 @@ e9 fd ff # loop forever 10 80 00 00 # disp32 = shift [label] 00 00 00 00 # imm32 74 08 # jump to $5 if = [label] -# 284: # otherwise use keyboard shift map # al <- *(keyboard shift map + eax) 8a # copy m8 at rm32 to r8 80 # 10/mod/*+disp32 000/r8/al 000/rm32/eax 00 87 00 00 # disp32 [label] eb 06 # jump to $6 [label] +# 28a: # $5: -# 28c: # al <- *(keyboard normal map + eax) 8a # copy m8 at rm32 to r8 80 # 10/mod/*+disp32 000/r8/al 000/rm32/eax 00 86 00 00 # disp32 [label] # $6: -# 292: # - if there's no character mapping, return 3c 00 # compare al, 0 74 13 # jump to epilogue if = [label] -# 296: +# 294: # - store al in keyboard buffer 88 # copy r8 to m8 at r32 81 # 10/mod/*+disp32 000/r8/al 001/rm32/ecx 30 80 00 00 # disp32 [label] -# 29c: # increment index fe # increment byte 05 # 00/mod/indirect 000/subop/increment 101/rm32/use-disp32 28 80 00 00 # disp32 [label] -# 2a2: # clear top nibble of index (keyboard buffer is circular) 80 # and byte 25 # 00/mod/indirect 100/subop/and 101/rm32/use-disp32 @@ -425,8 +415,8 @@ e9 fd ff # loop forever cf # iret # padding -# 2ac: - 00 00 00 00 +# 2aa: + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 diff --git a/baremetal/boot0.hex b/baremetal/boot0.hex index 793b2b9f..adb320d1 100644 --- a/baremetal/boot0.hex +++ b/baremetal/boot0.hex @@ -1,8 +1,7 @@ # A minimal bootable image that: # - loads more sectors past the first boot sector (using BIOS primitives) # - switches to 32-bit mode (giving up access to BIOS primitives) -# - sets up a handler for keyboard events -# - as an example program, prints '1' to the top-left position on screen (by writing to memory-mapped VGA memory) when the '1' key is typed +# - sets up a keyboard handler to print '1' at the top-left of screen when '1' is typed # # When it's ready to accept keys, it prints 'H' to the top-left of the screen. # @@ -226,10 +225,10 @@ e9 fb ff ff ff # loop forever # acknowledge interrupt b0 20 # al <- 0x20 e6 20 # port 0x20 <- al - # read keyboard status (TODO: why bit 0? Doesn't line up with https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html) -#? e4 64 # al <- port 0x64 -#? a8 01 # set zf if bit 0 (least significant) is not set -#? 74 11 # if bit 0 is not set, skip to epilogue + # check output buffer of 8042 keyboard controller (https://web.archive.org/web/20040604041507/http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/atkeyboard.html) + e4 64 # al <- port 0x64 + a8 01 # set zf if bit 0 (least significant) is not set + 74 11 # if bit 0 is not set, skip to epilogue # read keycode into eax 31 c0 # eax <- xor eax; 11/direct 000/r32/eax 000/rm32/eax e4 60 # al <- port 0x60 @@ -248,9 +247,8 @@ e9 fb ff ff ff # loop forever cf # iret # padding -# 14f - 00 -00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 +# 155 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |