diff options
| -rw-r--r-- | apps/bos/32bit.hex | 46 |
1 files changed, 24 insertions, 22 deletions
diff --git a/apps/bos/32bit.hex b/apps/bos/32bit.hex index 79642877..e8b1f21a 100644 --- a/apps/bos/32bit.hex +++ b/apps/bos/32bit.hex @@ -20,19 +20,23 @@ # 00: fa # cli # TODO: don't forget to reenable interrupts at some point 0f 01 16 # lgdt 00/mod/indirect 010/subop 110/rm32/TODO - 38 7c # *gdt_descriptor + 80 7c # *gdt_descriptor 0f 20 c0 # eax <- cr0 66 83 c8 01 # eax <- or 0x1 0f 22 c0 # cr0 <- eax - ea 50 7c 08 00 # far jump to initialize_32bit_mode after setting cs to the record at offset 8 in the gdt (gdt_code) + ea c0 7c 08 00 # far jump to initialize_32bit_mode after setting cs to the record at offset 8 in the gdt (gdt_code) # padding # 15: 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 +00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ## GDT: 3 records of 8 bytes each -# 20: +# 60: # gdt_start: # gdt_null: mandatory null descriptor 00 00 00 00 00 00 00 00 @@ -53,20 +57,25 @@ 00 # base[24:32] # gdt_end: -# 38: +# padding +# 78: + 00 00 00 00 00 00 00 00 + +# 80: # gdt_descriptor: 17 00 # final index of gdt = gdt_end - gdt_start - 1 - 20 7c 00 00 # start = gdt_start + 60 7c 00 00 # start = gdt_start # padding -# 3e: - 00 00 -# 40: +# 85: + 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 ## 32-bit code from this point (still some instructions not in SubX) -# 50: +# c0: # initialize_32bit_mode: 66 b8 10 00 # ax <- offset 16 from gdt_start 8e d8 # ds <- ax @@ -74,15 +83,16 @@ 8e c0 # es <- ax 8e e0 # fs <- ax 8e e8 # gs <- ax - e9 0d 00 00 00 # jump to 0x7c70, leaving some extra padding + e9 1d 00 00 00 # jump to 0x7cf0 # padding -# 63: +# d3: 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 ## 'application' SubX code: print one character to top-left of screen -# 70: +# f0: # Entry: # *0xb8000 <- 0x0f48 c7 # opcode @@ -97,17 +107,9 @@ e9 fb ff ff ff # loop forever -# more padding to 512 bytes +# padding to 512 bytes 00 -# 80: -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 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 00 00 00 00 00 00 00 00 00 00 +# 100: 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 |