tomoyuki-nakabayashi
commented
6 years ago 16bitと32bitモードをそれぞれコプロとして持って状態を引き継ぐ、という作りでどうだろうか？
Open tomoyuki-nakabayashi opened 6 years ago
tomoyuki-nakabayashi
commented
6 years ago 16bitと32bitモードをそれぞれコプロとして持って状態を引き継ぐ、という作りでどうだろうか？
tomoyuki-nakabayashi
commented
6 years ago まぁその前にデバッグ機能が必要だな。
tomoyuki-nakabayashi
commented
5 years ago 00000000 31C0 xor ax,ax
00000002 8ED8 mov ds,ax
00000004 8EC0 mov es,ax
00000006 8ED0 mov ss,ax
00000008 8EE0 mov fs,ax
0000000A 8EE8 mov gs,axMOV 0x8E RM
op1: ModR/M reg op2: ModR/M rm
tomoyuki-nakabayashi
commented
5 years ago # clear the direction flag (e.g. go forward in memory when using
# instructions like lodsb)
cldなんじゃらほい？
tomoyuki-nakabayashi
commented
5 years ago 
なるほど。
tomoyuki-nakabayashi
commented
5 years ago global_asm、そんなものもあるのか。
bootloader/main.rs
global_asm!(include_str!("boot.s"));
bootloader: file format elf64-x86-64
Disassembly of section .bootloader:
0000000000007c00 <_stack_end>:
7c00: 31 c0 xor %eax,%eax
7c02: 8e d8 mov %eax,%ds
7c04: 8e c0 mov %eax,%es
7c06: 8e d0 mov %eax,%ss
7c08: 8e e0 mov %eax,%fs
7c0a: 8e e8 mov %eax,%gs
7c0c: fc cld
7c0d: bc 00 7c 67 8d mov $0x8d677c00,%esp
7c12: 35 16 7d 00 00 xor $0x7d16,%eax
7c17: 66 e8 90 00 callw 7cab <spin>
...
0000000000007c1d <enable_a20>:
7c1d: e4 92 in $0x92,%al
7c1f: 0c 02 or $0x2,%al
7c21: e6 92 out %al,$0x92
0000000000007c23 <enter_protected_mode>:
7c23: fa cli
7c24: 1e (bad)
7c25: 06 (bad)
7c26: 67 0f 01 15 ad 7d 00 lgdt 0x7dad(%eip) # f9db <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x26b>
7c2d: 00
7c2e: 0f 20 c0 mov %cr0,%rax
7c31: 0c 01 or $0x1,%al
7c33: 0f 22 c0 mov %rax,%cr0
7c36: eb 00 jmp 7c38 <protected_mode>
0000000000007c38 <protected_mode>:
7c38: bb 08 00 8e db mov $0xdb8e0008,%ebx
7c3d: 8e c3 mov %ebx,%es
7c3f: 24 fe and $0xfe,%al
7c41: 0f 22 c0 mov %rax,%cr0
0000000000007c44 <unreal_mode>:
7c44: 07 (bad)
7c45: 1f (bad)
7c46: fb sti
7c47: bb 01 0f 66 b8 mov $0xb8660f01,%ebx
7c4c: 00 8f 0b 00 3e 67 add %cl,0x673e000b(%rdi)
7c52: 89 18 mov %ebx,(%rax)
0000000000007c54 <check_int13h_extensions>:
7c54: b4 41 mov $0x41,%ah
7c56: bb aa 55 cd 13 mov $0x13cd55aa,%ebx
7c5b: 0f 82 9c 00 67 66 jb 66677cfd <__bootloader_end+0x66661efd>
0000000000007c5f <load_second_stage_from_disk>:
7c5f: 67 66 8d 05 00 7e 00 lea 0x7e00(%eip),%ax # fa67 <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x2f7>
7c66: 00
7c67: a3 c5 7d 67 66 8d 1d movabs %eax,0x5e001d8d66677dc5
7c6e: 00 5e
7c70: 01 00 add %eax,(%rax)
7c72: 66 29 c3 sub %ax,%bx
7c75: 66 c1 eb 09 shr $0x9,%bx
7c79: 67 89 1d c3 7d 00 00 mov %ebx,0x7dc3(%eip) # fa43 <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x2d3>
7c80: 67 66 8d 1d 00 7c 00 lea 0x7c00(%eip),%bx # f888 <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x118>
7c87: 00
7c88: 66 29 d8 sub %bx,%ax
7c8b: 66 c1 e8 09 shr $0x9,%ax
7c8f: 66 a3 c9 7d 67 8d 35 movabs %ax,0x7dc1358d677dc9
7c96: c1 7d 00
7c99: 00 b4 42 cd 13 72 64 add %dh,0x647213cd(%rdx,%rax,2)
0000000000007ca0 <jump_to_second_stage>:
7ca0: 67 66 8d 05 43 7e 00 lea 0x7e43(%eip),%ax # faeb <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x37b>
7ca7: 00
7ca8: 66 ff e0 jmpw *%ax
0000000000007cab <spin>:
7cab: eb fe jmp 7cab <spin>
0000000000007cad <println>:
7cad: 66 e8 0c 00 callw 7cbd <println+0x10>
7cb1: 00 00 add %al,(%rax)
7cb3: b0 0d mov $0xd,%al
7cb5: 66 e8 15 00 callw 7cce <print_done>
7cb9: 00 00 add %al,(%rax)
7cbb: b0 0a mov $0xa,%al
7cbd: eb 11 jmp 7cd0 <print_char>
0000000000007cbf <print>:
7cbf: fc cld
0000000000007cc0 <print_loop>:
7cc0: 67 ac lods %ds:(%esi),%al
7cc2: 84 c0 test %al,%al
7cc4: 74 08 je 7cce <print_done>
7cc6: 66 e8 04 00 callw 7cce <print_done>
7cca: 00 00 add %al,(%rax)
7ccc: eb f2 jmp 7cc0 <print_loop>
0000000000007cce <print_done>:
7cce: 66 c3 retw
0000000000007cd0 <print_char>:
7cd0: b4 0e mov $0xe,%ah
7cd2: cd 10 int $0x10
7cd4: 66 c3 retw
0000000000007cd6 <print_hex>:
7cd6: b9 04 00 88 f8 mov $0xf8880004,%ecx
0000000000007cd9 <.lp>:
7cd9: 88 f8 mov %bh,%al
7cdb: c0 e8 04 shr $0x4,%al
7cde: 3c 0a cmp $0xa,%al
7ce0: 72 02 jb 7ce4 <.below_0xA>
7ce2: 04 07 add $0x7,%al
0000000000007ce4 <.below_0xA>:
7ce4: 04 30 add $0x30,%al
7ce6: 66 e8 e4 ff callw 7cce <print_done>
7cea: ff (bad)
7ceb: ff c1 inc %ecx
7ced: e3 04 jrcxz 7cf3 <error>
7cef: e2 e8 loop 7cd9 <.lp>
7cf1: 66 c3 retw
0000000000007cf3 <error>:
7cf3: 66 e8 b4 ff callw 7cab <spin>
7cf7: ff (bad)
7cf8: ff (bad)
7cf9: eb b0 jmp 7cab <spin>
0000000000007cfb <no_int13h_extensions>:
7cfb: 67 8d 35 62 7d 00 00 lea 0x7d62(%eip),%esi # fa64 <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x2f4>
7d02: eb ef jmp 7cf3 <error>
0000000000007d04 <second_stage_load_failed>:
7d04: 67 8d 35 83 7d 00 00 lea 0x7d83(%eip),%esi # fa8e <_ZN4core3fmt5write17h4a9b46e3234c9fa5E+0x31e>
7d0b: eb e6 jmp 7cf3 <error>
0000000000007d0d <kernel_load_failed>:
7d0d: 67 8d 35 18 7e 00 00 lea 0x7e18(%eip),%esi # fb2c <_ZN4core3fmt9Formatter12pad_integral17hda853aacc478d35fE+0x2c>
7d14: eb dd jmp 7cf3 <error>
0000000000007d16 <boot_start_str>:
7d16: 42 6f rex.X outsl %ds:(%rsi),(%dx)
7d18: 6f outsl %ds:(%rsi),(%dx)
7d19: 74 69 je 7d84 <second_stage_load_failed_str+0x1>
7d1b: 6e outsb %ds:(%rsi),(%dx)
7d1c: 67 20 28 and %ch,(%eax)
7d1f: 66 69 72 73 74 20 imul $0x2074,0x73(%rdx),%si
7d25: 73 74 jae 7d9b <second_stage_load_failed_str+0x18>
7d27: 61 (bad)
7d28: 67 65 29 2e sub %ebp,%gs:(%esi)
7d2c: 2e 2e 00 42 6f cs add %al,%cs:0x6f(%rdx)
0000000000007d2f <second_stage_start_str>:
7d2f: 42 6f rex.X outsl %ds:(%rsi),(%dx)
7d31: 6f outsl %ds:(%rsi),(%dx)
7d32: 74 69 je 7d9d <second_stage_load_failed_str+0x1a>
7d34: 6e outsb %ds:(%rsi),(%dx)
7d35: 67 20 28 and %ch,(%eax)
7d38: 73 65 jae 7d9f <second_stage_load_failed_str+0x1c>
7d3a: 63 6f 6e movslq 0x6e(%rdi),%ebp
7d3d: 64 20 73 74 and %dh,%fs:0x74(%rbx)
7d41: 61 (bad)
7d42: 67 65 29 2e sub %ebp,%gs:(%esi)
7d46: 2e 2e 00 45 72 cs add %al,%cs:0x72(%rbp)
0000000000007d49 <error_str>:
7d49: 45 72 72 rex.RB jb 7dbe <flatdesc+0x5>
7d4c: 6f outsl %ds:(%rsi),(%dx)
7d4d: 72 3a jb 7d89 <second_stage_load_failed_str+0x6>
7d4f: 20 00 and %al,(%rax)
0000000000007d51 <no_cpuid_str>:
7d51: 4e 6f rex.WRX outsl %ds:(%rsi),(%dx)
7d53: 20 43 50 and %al,0x50(%rbx)
7d56: 55 push %rbp
7d57: 49 rex.WB
7d58: 44 20 73 75 and %r14b,0x75(%rbx)
7d5c: 70 70 jo 7dce <dap_start_lba+0x5>
7d5e: 6f outsl %ds:(%rsi),(%dx)
7d5f: 72 74 jb 7dd5 <dap_start_lba+0xc>
...
0000000000007d62 <no_int13h_extensions_str>:
7d62: 4e 6f rex.WRX outsl %ds:(%rsi),(%dx)
7d64: 20 73 75 and %dh,0x75(%rbx)
7d67: 70 70 jo 7dd9 <dap_start_lba+0x10>
7d69: 6f outsl %ds:(%rsi),(%dx)
7d6a: 72 74 jb 7de0 <dap_start_lba+0x17>
7d6c: 20 66 6f and %ah,0x6f(%rsi)
7d6f: 72 20 jb 7d91 <second_stage_load_failed_str+0xe>
7d71: 69 6e 74 31 33 68 20 imul $0x20683331,0x74(%rsi),%ebp
7d78: 65 78 74 gs js 7def <dap_start_lba+0x26>
7d7b: 65 6e outsb %gs:(%rsi),(%dx)
7d7d: 73 69 jae 7de8 <dap_start_lba+0x1f>
7d7f: 6f outsl %ds:(%rsi),(%dx)
7d80: 6e outsb %ds:(%rsi),(%dx)
7d81: 73 00 jae 7d83 <second_stage_load_failed_str>
0000000000007d83 <second_stage_load_failed_str>:
7d83: 46 61 rex.RX (bad)
7d85: 69 6c 65 64 20 74 6f imul $0x206f7420,0x64(%rbp,%riz,2),%ebp
7d8c: 20
7d8d: 6c insb (%dx),%es:(%rdi)
7d8e: 6f outsl %ds:(%rsi),(%dx)
7d8f: 61 (bad)
7d90: 64 20 73 65 and %dh,%fs:0x65(%rbx)
7d94: 63 6f 6e movslq 0x6e(%rdi),%ebp
7d97: 64 20 73 74 and %dh,%fs:0x74(%rbx)
7d9b: 61 (bad)
7d9c: 67 65 20 6f 66 and %ch,%gs:0x66(%edi)
7da1: 20 62 6f and %ah,0x6f(%rdx)
7da4: 6f outsl %ds:(%rsi),(%dx)
7da5: 74 6c je 7e13 <_second_stage_start_addr+0x13>
7da7: 6f outsl %ds:(%rsi),(%dx)
7da8: 61 (bad)
7da9: 64 65 72 00 fs gs jb 7dad <gdtinfo>
0000000000007dad <gdtinfo>:
7dad: 0f 00 (bad)
7daf: b1 7d mov $0x7d,%cl
0000000000007db1 <gdt>:
...
0000000000007db9 <flatdesc>:
7db9: ff (bad)
7dba: ff 00 incl (%rax)
7dbc: 00 00 add %al,(%rax)
7dbe: 92 xchg %eax,%edx
7dbf: cf iret
...
0000000000007dc1 <dap>:
7dc1: 10 00 adc %al,(%rax)
0000000000007dc3 <dap_blocks>:
...
0000000000007dc5 <dap_buffer_addr>:
...
0000000000007dc7 <dap_buffer_seg>:
...
0000000000007dc9 <dap_start_lba>:
...
7dfd: 00 55 aa add %dl,-0x56(%rbp)良く見ると命令列がバグっているな。x86_64でdeasembleされているっぽい。
tomoyuki-nakabayashi
commented
5 years ago $ objdump -d -m i386 -Maddr16,data16 bootloader | lessこうか。
https://github.com/rust-osdev/bootloader/blob/master/linker.ld
メモリマップはこれ。 さて、長い闘いになるかな。