wok diff runcom/stuff/debug8086.S @ rev 11674
add runcom
| author | Pascal Bellard <pascal.bellard@slitaz.org> |
|---|---|
| date | Sat Feb 18 09:00:05 2012 +0100 (2012-02-18) |
| parents | |
| children | f32d3ba00836 |
line diff
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/runcom/stuff/debug8086.S Sat Feb 18 09:00:05 2012 +0100 1.3 @@ -0,0 +1,477 @@ 1.4 +// Usage: 1.5 +// 1.6 +// f DX:CX load one CHS sector to 0000:7C00 1.7 +// t trace one step 1.8 +// g <address> go to adrs 1.9 +// d <address> display 16 bytes, CR for next 16 bytes... 1.10 +// e <address> <words>... enter memory byte/word/dword 1.11 +// m <segment> self move 1.12 +// + <segment> default segment offset 1.13 +// 1.14 +// Example: 1.15 +// m 0FC0 move debugger to 0FC0:0000 0FC0:01FF 1.16 +// f 1 read floppy boot sector to 0000:7C00 1.17 +// f 80 1 read hard disk master boot sector to 0000:7C00 1.18 +// g 7C0E ... 1.19 + 1.20 +#define ADJESDI 16 bytes add segment overflow support for e and d 1.21 +#define ASCIIDUMP 20 bytes display hexa and ascii datas 1.22 +#define INPUTBUFFER 2 bytes overload init code with a 32+ bytes input buffer 1.23 +//#define CPU186 -26 bytes 80186+ CPU 1.24 + 1.25 +.macro pusham 1.26 + pushw %ax 1.27 + pushw %cx 1.28 + pushw %dx 1.29 + pushw %bx 1.30 + movw %sp, %bx 1.31 + leaw 14(%bx), %bx # adjust SP with [FLAGS CS IP AX CX DX BX] size 1.32 + pushw %bx # %sp 1.33 + pushw %bp 1.34 + pushw %si 1.35 + pushw %di 1.36 +.endm 1.37 + 1.38 +.macro popam 1.39 + popw %di 1.40 + popw %si 1.41 + popw %bp 1.42 + popw %ax # %sp 1.43 + popw %bx 1.44 + popw %dx 1.45 + popw %cx 1.46 + popw %ax 1.47 +.endm 1.48 + 1.49 +#ifdef INPUTBUFFER 1.50 +//#define ABS(x) (x-(setvectors-_start)) 1.51 +#define ABS(x) (x-30) 1.52 +#else 1.53 +#define ABS(x) (x) 1.54 +#endif 1.55 + 1.56 +#define SEGREGSZ 6 1.57 +#define REGSZ 16 1.58 +#define USER_SP REGSZ+SEGREGSZ-10(%bp) 1.59 +#define USER_FLAGS REGSZ+SEGREGSZ+4(%bp) 1.60 +#define USER_FLAGS_HIGH REGSZ+SEGREGSZ+5(%bp) 1.61 +#define USER_IP REGSZ+SEGREGSZ(%bp) 1.62 +#define USER_CS REGSZ+SEGREGSZ+2(%bp) 1.63 +#define USER_CSIP REGSZ+SEGREGSZ(%bp) 1.64 + 1.65 +.macro initcode 1.66 + movw $0x0FC0, %di # move (and jump) to 0FC0:0000 1.67 + subw $_startz-_start, USER_IP 1.68 + movw USER_IP, %ax 1.69 +#ifdef CPU186 1.70 + cld # ensure movsb will work 1.71 + shrw $4, %ax # _start MUST be aligned on paragraph 1.72 +#else 1.73 + movb $4, %cl 1.74 + shrw %cl, %ax # _start MUST be aligned on paragraph 1.75 +#endif 1.76 + addw USER_CS, %ax # normalize %cs to have _start=0 1.77 + movw %ax, %ds 1.78 +.endm 1.79 + .text 1.80 + .code16 1.81 +#ifdef CPU186 1.82 + .arch i186 1.83 +#else 1.84 + .arch i8086 1.85 +#endif 1.86 + .org 0 1.87 + 1.88 + .globl _start 1.89 +_start: 1.90 + pushf 1.91 + pushw %cs 1.92 + stc 1.93 + call init # the start code will be overwritten by the input buffer 1.94 +_startz: 1.95 + 1.96 +#ifdef INPUTBUFFER 1.97 +isinit: 1.98 + initcode 1.99 + movw $setvectors, %si 1.100 + jmp moveself 1.101 +#endif 1.102 + 1.103 +setvectors: 1.104 + xorw %si, %si # set interrupt vectors in 0 segment 1.105 + movw %si, %ds 1.106 + movb $0xF9, %ch # skip nmi 1.107 +hooklp: # interrupts: 0=div0 1=step 2=nmi 3=brk 4=ov 5=bound 6=invalid 1.108 + movw $ABS(dbgstart), (%si) # set %cs:dbgstart 1.109 + lodsw # %si += 2 1.110 + movw %cs, (%si) # to interrupt vector 1.111 +skiphook: 1.112 + lodsw # %si += 2 1.113 + shrb $1,%ch 1.114 + jnc skiphook 1.115 + jnz hooklp # note %cx will be cleared: SP will be untouched 1.116 +#ifdef CPU186 1.117 + decw (3-7)*4(%si) # update int3 vector 1.118 +#else 1.119 + movb $ABS(int3), (3-7)*4(%si) # update int3 vector 1.120 +#endif 1.121 + jmp dbgstartz # registers are already pushed by startup code 1.122 + 1.123 +regs: 1.124 + .ascii "ss" 1.125 + .ascii "es" 1.126 + .ascii "ds" 1.127 + .ascii "di" 1.128 + .ascii "si" 1.129 + .ascii "bp" 1.130 + .ascii "sp" 1.131 + .ascii "bx" 1.132 + .ascii "dx" 1.133 + .ascii "cx" 1.134 + .ascii "ax" 1.135 + .ascii "ip" 1.136 + .ascii "cs" 1.137 +# Bit Label Desciption 1.138 +# --------------------------- 1.139 +# 0 CF Carry flag 1.140 +# 2 PF Parity flag 1.141 +# 4 AF Auxiliary carry flag 1.142 +# 6 ZF Zero flag 1.143 +# 7 SF Sign flag 1.144 +# 8 TF Trap flag 1.145 +# 9 IF Interrupt enable flag 1.146 +# 10 DF Direction flag 1.147 +# 11 OF Overflow flag 1.148 + .ascii "oditsz?a?p c=" # flags bits 1.149 + 1.150 +int3: 1.151 +#ifdef CPU186 1.152 + .byte 0x68 # push $0x086A OV UP DI NT PL ZR - NA - PO - NC 1.153 +# interrupt entry point: the registers [FLAGS CS IP] are already pushed 1.154 +dbgstart: 1.155 + .byte 0x6A, 0x08 # push $0x08 NV UP DI NT PL NZ - NA - PO - NC 1.156 + popf 1.157 +init: 1.158 + pushaw # [FLAGS CS IP] AX CX DX BX SP BP SI DI [DS ES SS] 1.159 +#else 1.160 + stc 1.161 + .byte 0x73 # jnc 1.162 +# interrupt entry point: the registers [FLAGS CS IP] are already pushed 1.163 +dbgstart: 1.164 + clc 1.165 + pushw %ax 1.166 + sbbw %ax,%ax # copy CF to SF 1.167 + clc 1.168 + popw %ax 1.169 +init: 1.170 + cld # ensure movsb will work 1.171 + pusham # [FLAGS CS IP] AX CX DX BX SP BP SI DI [DS ES SS] 1.172 +#endif 1.173 + pushw %ds 1.174 + pushw %es 1.175 + pushw %ss 1.176 + movw %sp, %bp 1.177 +#ifdef CPU186 1.178 + pushf 1.179 + addw $6, USER_SP # adjust SP with [FLAGS CS IP] size 1.180 + popf 1.181 +#endif 1.182 + jc isinit 1.183 + jns notint3 1.184 + decw USER_IP 1.185 + lesw USER_CSIP, %di 1.186 +#define OPCODE_BRK 0xCC 1.187 + .byte 0xB0 # movb $IM, %al 1.188 +break: 1.189 + .byte 0xCC 1.190 + stosb 1.191 +notint3: 1.192 +dbgstartz: 1.193 +dbgregslp: 1.194 + call getcmd 1.195 + .byte 0x81, 0xC3 # addw $0, %bx 1.196 +offset_value: 1.197 + .word 0 1.198 + movw %bx, %es 1.199 + xchgw %ax, %di 1.200 + subb $'m', %al 1.201 + jne isinotmove 1.202 +#ifdef INPUTBUFFER 1.203 +ismove: 1.204 + xchgw %ax, %si 1.205 +moveself: 1.206 +#else 1.207 +isinit: 1.208 + jmp ismove 1.209 + initcode 1.210 +ismove: 1.211 +#endif 1.212 + movw %di, %es # move code to %di:0 1.213 + pushw %di 1.214 +#ifdef INPUTBUFFER 1.215 + xorw %di, %di # and jmp into (%di:setvectors) with retf 1.216 +#else 1.217 + movw $setvectors, %di # and jmp into (%di:setvectors) with retf 1.218 + movw %di, %si 1.219 +#endif 1.220 + movw $_end-setvectors, %cx 1.221 + pushw %di 1.222 + rep movsb 1.223 + retf 1.224 + 1.225 +isinotmove: 1.226 + subb $'+'-'m', %al 1.227 + jne not_offset 1.228 + movw %di, ABS(offset_value) 1.229 +not_offset: 1.230 + orb $1, USER_FLAGS_HIGH # set TF 1.231 + subb $'t'-'+', %al 1.232 + je done 1.233 + subb $'d'-'t', %al 1.234 + xchgw %ax, %cx 1.235 + jcxz dump # 'd' ? 1.236 + loop noenter # 'e' ? 1.237 +nextval: 1.238 + call getval 1.239 + jcxz dbgregslp 1.240 + xchgb %dl, %dh 1.241 +mextmsb: 1.242 + stosb 1.243 + xchgw %ax, %dx 1.244 + xchgb %al, %dh 1.245 +#ifdef ADJESDI 1.246 + call adjustESDI 1.247 +#endif 1.248 + decw %cx 1.249 + loopne mextmsb 1.250 + jmp nextval 1.251 +noenter: 1.252 + loop not_floppy_load # f DX:CX ? 1.253 + movw %es, %dx 1.254 + movw %cx, %es 1.255 + movw %di, %cx 1.256 + movw $0x0201, %ax 1.257 + movw $0x7C00, %bx 1.258 + pushw %bx 1.259 + int $0x13 1.260 + popw %di 1.261 +godbgregslpifc: 1.262 + jc dbgregslp 1.263 +dump: 1.264 + movw %es, %ax 1.265 + call putax 1.266 + movw %di, %ax 1.267 + call putax 1.268 + movw $16, %cx 1.269 +dhex: 1.270 + movb %es:(%di), %ah 1.271 +#ifdef ASCIIDUMP 1.272 + movb %ah, (%si) 1.273 + incw %si 1.274 +#endif 1.275 +#ifdef ADJESDI 1.276 + call incESDI 1.277 +#else 1.278 + incw %di 1.279 +#endif 1.280 + movb $0x01, %dh # the data has 2 digits 1.281 + call putx 1.282 + loop dhex 1.283 +#ifdef ASCIIDUMP 1.284 + movb $16, %cl 1.285 + subw %cx, %si 1.286 +dascii: 1.287 + lodsb 1.288 + cmpb $0x7F, %al 1.289 + jnc skipascii 1.290 + cmpb $0x20, %al 1.291 + cmc 1.292 +skipascii: 1.293 + call dbgputcbit 1.294 + loop dascii 1.295 +#endif 1.296 + call dbgputcr 1.297 + int $0x16 1.298 + cmpb $13, %al 1.299 + je dump 1.300 +notdump: 1.301 +not_floppy_load: 1.302 + stc 1.303 + loop godbgregslpifc # g ? 1.304 +isgo: 1.305 + andb $0xfe, USER_FLAGS_HIGH # clear TF 1.306 + xchgw %ax, %cx 1.307 + jcxz done 1.308 +setbreak: 1.309 + movb $OPCODE_BRK, %al 1.310 + xchgb %al, %es:(%di) 1.311 + movb %al, ABS(break) 1.312 +done: 1.313 + popw %ax # %ss 1.314 + popw %es 1.315 + popw %ds 1.316 +#ifdef CPU186 1.317 + popaw 1.318 +#else 1.319 + popam 1.320 +#endif 1.321 + iret 1.322 + 1.323 +#ifdef ADJESDI 1.324 +adjustESDI: 1.325 + decw %di 1.326 +incESDI: 1.327 + incw %di 1.328 + jnz esok 1.329 + pushw %es 1.330 + addb $0x10,-3(%bp) 1.331 + popw %es 1.332 +esok: 1.333 + ret 1.334 +#endif 1.335 + 1.336 +putreg: 1.337 + call dbgput2c 1.338 + movb $'=', %al 1.339 + call dbgputc 1.340 +putr16: 1.341 +# movw _start-ABS(regs)-2(%bp,%si), %ax 1.342 + .byte 0x8b, 0x42, _start-ABS(regs)-2 1.343 +putax: 1.344 + movb $0x07, %dh # the data has 4 digits 1.345 +putx: 1.346 +putxlp: 1.347 +#ifdef CPU186 1.348 + rolw $4, %ax 1.349 +#else 1.350 + pushw %cx 1.351 + movb $4, %cl 1.352 + rolw %cl, %ax 1.353 + popw %cx 1.354 +#endif 1.355 + pushw %ax 1.356 + andb $0xf, %al 1.357 + addb $0x90, %al 1.358 + daa 1.359 + adcb $0x40, %al 1.360 + daa 1.361 + call dbgputc 1.362 + popw %ax 1.363 + shrb $1, %dh 1.364 + jc putxlp 1.365 +dbgputcbit: 1.366 + jc dbgputc 1.367 + mov $0x20, %al 1.368 +dbgputc: 1.369 + movw $7, %bx 1.370 + mov $0xE, %ah 1.371 + int $0x10 1.372 + xchgw %ax, %bx 1.373 + ret 1.374 + 1.375 +getline: 1.376 + movw $ABS(regs), %si 1.377 + movw $13, %cx 1.378 +regslp: 1.379 + call putreg # display register name and value 1.380 + loop regslp 1.381 + movw USER_FLAGS, %dx 1.382 + pushw %si 1.383 + movb $13, %cl 1.384 + stc # add trailing = 1.385 + rcrw %cl, %dx 1.386 +nextbit: 1.387 + lodsb 1.388 + shlw $1, %dx 1.389 + call dbgputcbit # display active flags bits 1.390 + loop nextbit 1.391 + popw %si 1.392 + movb $8, %cl 1.393 +stacklp: 1.394 + lodsw # si += 2 1.395 + call putr16 # display flags and the beginning of the stack 1.396 + loop stacklp 1.397 + call dbgputcr 1.398 +getlinebs: 1.399 + cmpw $ABS(buffer), %si 1.400 + je getc 1.401 + decw %si 1.402 +getlinelp: 1.403 + call dbgputc 1.404 +getc: 1.405 + int $0x16 1.406 + cmpb $8, %al 1.407 + je getlinebs 1.408 + orb $0x20, %al 1.409 + movb %al, (%si) 1.410 + inc %si 1.411 + cmpb $0x2D, %al 1.412 + jne getlinelp 1.413 +dbgputcr: 1.414 + movw $ABS(crlf), %si 1.415 +dbgput2c: 1.416 + call dbgput1c 1.417 +dbgput1c: 1.418 + lodsb 1.419 + jmp dbgputc 1.420 + 1.421 +getcmd: 1.422 + pushw %cs 1.423 + popw %ds 1.424 + call getline 1.425 + lodsb 1.426 + xchgw %ax, %di 1.427 +# get value in DX:AX, BX is segment CX is digits count. 1.428 +getval: 1.429 + xorw %bx, %bx 1.430 + xorw %cx, %cx 1.431 +getvalz: 1.432 + pushw %bx # save segment 1.433 + xorw %bx, %bx 1.434 + mul %bx # clear %dx:%ax 1.435 + decw %cx 1.436 +isx: 1.437 + incw %cx 1.438 + orb $0xE0, %dh 1.439 +getvalbit: 1.440 + shlw $1, %bx 1.441 + rclw $1, %dx 1.442 + jc getvalbit 1.443 + orb %al, %bl 1.444 +gotspc: 1.445 + lodsb 1.446 + cmpb $0x20, %al # space ? 1.447 + jne notspc 1.448 + jcxz gotspc 1.449 +notspc: 1.450 + sub $'0', %al 1.451 + cmpb $10, %al # in 0..9 ? 1.452 + jb isx 1.453 + sub $'a'-'0'-10, %al 1.454 + cmpb $16, %al # in a..f ? 1.455 + jb isx 1.456 + cmpb $':'-'a'+10, %al 1.457 + popw %ax 1.458 + je getvalz # store segment in %bx 1.459 + xchgw %ax, %bx 1.460 + pushw %dx 1.461 +#ifdef CPU186 1.462 + shlw $12, %dx 1.463 +#else 1.464 + pushw %cx 1.465 + movb $12, %cl 1.466 + shlw %cl, %dx 1.467 + popw %cx 1.468 +#endif 1.469 + addw %dx, %bx 1.470 + popw %dx 1.471 + ret 1.472 + 1.473 +crlf: 1.474 + .byte 13,10 1.475 +_end: 1.476 +buffer: 1.477 + 1.478 + .org 510 1.479 + .byte 0x55, 0xAA 1.480 +