wok diff plop/stuff/bootloader.S @ rev 24936
created recipe for mypaint-brushes
| author | Hans-G?nter Theisgen |
|---|---|
| date | Thu Apr 14 09:08:33 2022 +0100 (2022-04-14) |
| parents | |
| children | d1f31f5f6401 |
line diff
1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/plop/stuff/bootloader.S Thu Apr 14 09:08:33 2022 +0100 1.3 @@ -0,0 +1,655 @@ 1.4 +// Image/zImage & tiny bzImage linux kernel boot sector, (C) SliTaz, GPL2. 1.5 + 1.6 +SYSSEG = 0x1000 1.7 +setup_sects = 497 1.8 +syssize = 500 1.9 +cmd_line_ptr = 0x228 1.10 + 1.11 + .text 1.12 + .code16 1.13 + .org 0 1.14 + .globl _start 1.15 +_start: 1.16 + 1.17 +#define CODESZ 512 /* patched by installer */ 1.18 + 1.19 +// Default kernel format is 386 Image/zImage 1.20 +//#define BZIMAGE 0x207 /* setup version ; for bzImage < 512 Kb only */ 1.21 +//#define ELKS /* 8086/286 linux port */ 1.22 + 1.23 +/* some extra features */ 1.24 +#define EXE_SUPPORT real mode dos .exe file support +208/264 1.25 +#define CMDLINE dos kernel cmdline support +45 1.26 +#define VCPI VCPI 4.0 support (386+) +109 1.27 +#define SHUTDOWNDOS shutdown DOS services +29 1.28 + 1.29 +/* some contraints to reduce the code size */ 1.30 +//#define FLOPPY_1440K_ONLY 1.44M floppies support only -26 1.31 +#define FLOPPY_HAS_2_SIDES hardcoded heads count to 2 -15 1.32 +//#define NO_CMDLINE_SHRINK remove heading spaces ? -6-21 1.33 +//#define NO_CMDLINE_FILE remove @cmdline file support ? -21 1.34 +//#define NO_DOTS show progression dots ? -5 1.35 +#ifndef BZIMAGE 1.36 +#define TINY_ZIMAGE system < 64Kb ? -11 1.37 +#define NO_MINSETUP default setup (dos only) ? -4 1.38 +//#define NO_CURSOR_DEFINITION -8 1.39 +#endif 1.40 + 1.41 +#ifdef ELKS 1.42 + .arch i8086 1.43 +INITSEG = 0x0100 1.44 +SETUPSEG = 0x0120 1.45 +#define ONLY8086 1.46 +#undef BZIMAGE 1.47 +#undef VCPI 1.48 +#else 1.49 +INITSEG = 0x9000 1.50 +SETUPSEG = 0x9020 1.51 +#endif 1.52 + 1.53 +.macro shlclw cnt,obj 1.54 +#ifdef ONLY8086 1.55 + movb \cnt,%cl 1.56 + shlw %cl,\obj 1.57 +#else 1.58 + shlw \cnt,\obj 1.59 +#endif 1.60 +.endm 1.61 + 1.62 +.macro shrclw cnt,obj 1.63 +#ifdef ONLY8086 1.64 + movb \cnt,%cl 1.65 + shrw %cl,\obj 1.66 +#else 1.67 + shrw \cnt,\obj 1.68 +#endif 1.69 +.endm 1.70 + 1.71 +#ifdef EXE_SUPPORT 1.72 +#define EXEADRS(x) (x+0xE0) 1.73 +#define FLAT20(x) (x+16*INITSEG) 1.74 + 1.75 +.macro trace_int19 1.76 +#ifdef ONLY8086 1.77 + xorw %si, %si 1.78 + movw %si, %ds 1.79 + pushw 4+2(%si) 1.80 + pushw 4(%si) 1.81 + movw $step19, 4(%si) 1.82 + movw $INITSEG, 4+2(%si) 1.83 +#else 1.84 + pushl $4 1.85 + popw %si 1.86 + popw %ds 1.87 + pushl (%si) 1.88 + movl $step19+(INITSEG<<16), (%si) 1.89 +#endif 1.90 + pushfw 1.91 + popw %ax 1.92 + incb %ah # set TF 1.93 + pushw %ax 1.94 + popfw 1.95 + ljmp *4*0x19-4(%si) 1.96 +.endm 1.97 + 1.98 +stacktop = 0x9E00 # in 0x8000 .. 0xA000 1.99 + decw %bp // Magic number: MZ 1.100 + popw %dx 1.101 + jmp start // Bytes on last page of file 1.102 + .word (CODESZ+511)/512 // Pages in file INSTALLER 1.103 + .word 0 // Relocations 1.104 + .word (end_header-_start)/16 // Size of header in paragraphs 1.105 + .word 4096 // Minimum extra paragraphs needed 1.106 + .word -1 // Maximum extra paragraphs needed 1.107 + .word (CODESZ+15)/16 // Initial (relative) SS value INSTALLER 1.108 + .word stacktop // Initial SP value 1.109 + .word 0 // Checksum INSTALLER? 1.110 + .word EXEADRS(comstart) // Initial IP value 1.111 + .word 0xFFF0 // Initial (relative) CS value 1.112 +// .word 0x001C // File address of relocation table 1.113 +// .word 0,0,0 // Overlay number 1.114 +#else 1.115 +#undef VCPI 1.116 +#endif 1.117 +start: 1.118 + xorw %ax, %ax # %ax = 0 1.119 +zeroed = 12 # zeroed registers 1.120 + movw $zeroed/2, %cx # clear gdt + offset, %ds, limits 1.121 +stacktop = 0x9E00 # in 0x8000 .. 0xA000 (+zeroed+12) 1.122 +#ifdef ONLY8086 1.123 + movw $INITSEG, %bx 1.124 +#else 1.125 + pushw $INITSEG 1.126 +#endif 1.127 +end_header: 1.128 + cld # assume nothing 1.129 +#if defined(BZIMAGE) && BZIMAGE >= 0x202 1.130 + popw %es # %es contain INITSEG 1.131 + movw %es, %di 1.132 +#else 1.133 + # cmdline offset at 0x22 1.134 + movw $stacktop, %di # stacktop is an arbitrary value >= 1.135 + # length of bootsect + length of 1.136 + # setup + room for stack; 1.137 + # 12 is disk parm size. 1.138 +# ifdef ONLY8086 1.139 + pushw %bx 1.140 +# endif 1.141 + popw %es # %es contain INITSEG 1.142 +#endif 1.143 + pushw %es 1.144 + popw %ss # %es = %ss = INITSEG 1.145 + movw %di, %sp # put stack at INITSEG:stacktop-... 1.146 +#ifdef EXE_SUPPORT 1.147 + cwd # force %dx = 0 (floppy only) 1.148 +#endif 1.149 + 1.150 +# Many BIOS's default disk parameter tables will not recognize 1.151 +# multi-sector reads beyond the maximum sector number specified 1.152 +# in the default diskette parameter tables - this may mean 7 1.153 +# sectors in some cases. 1.154 +# 1.155 +# Since single sector reads are slow and out of the question, 1.156 +# we must take care of this by creating new parameter tables 1.157 +# (for the first disk) in RAM. We can set the maximum sector 1.158 +# count to 36 - the most we will encounter on an ED 2.88. 1.159 +# 1.160 +# High doesn't hurt. Low does. Let's use the max: 63 1.161 + 1.162 + rep # don't worry about cld 1.163 + stosw # already done above 1.164 + popw %bx # offset = 0 1.165 + popw %ds # %ds = 0 1.166 + 1.167 + movb setup_sects+0x7C00, %al # read bootsector + setup (%ds = 0) 1.168 + incw %ax 1.169 + 1.170 + ldsw 0x78(%bx), %si # %ds:%bx+0x78 is parameter table address 1.171 + pushw %es 1.172 + pushw %di 1.173 + movb $6, %cl # copy 12 bytes 1.174 + rep # don't worry about cld 1.175 + movsw # already done above 1.176 + movw %cx, %ds # %ds = 0 1.177 +#ifdef ONLY8086 1.178 + popw 0x78(%bx) # update parameter table address 1.179 + popw 0x78+2(%bx) 1.180 +#else 1.181 + popl 0x78(%bx) # update parameter table address 1.182 +#endif 1.183 + pushw %ss 1.184 + popw %ds # now %ds = %es = %ss = INITSEG 1.185 + movb $63, 0x4-12(%di) # patch sector count, %di = stacktop 1.186 + 1.187 + xchg %ax, %di # sector count 1.188 + popw %ax # limits = 0 1.189 + incw %cx # cylinder 0, sector 1, clear Z 1.190 + call read_first_sectors # read setup 1.191 + 1.192 +# This routine loads the system at address LOADSEG, making sure 1.193 +# no 64kB boundaries are crossed. We try to load it as fast as 1.194 +# possible, loading whole tracks whenever we can. 1.195 + 1.196 + movw syssize, %di 1.197 + decw %di 1.198 + shrclw $9-4, %di 1.199 + incw %di 1.200 + movw $SYSSEG, %cx 1.201 +#ifdef BZIMAGE 1.202 + push %cx 1.203 +#endif 1.204 + call read_sectorsCX 1.205 + 1.206 +# This procedure turns off the floppy drive motor, so 1.207 +# that we enter the kernel in a known state, and 1.208 +# don't have to worry about it later. 1.209 + 1.210 +kill_motor: 1.211 + xchgw %ax, %di # reset FDC (%di < 128) 1.212 + int $0x13 1.213 + 1.214 +# After that (everything loaded), we jump to the setup-routine 1.215 +# loaded directly after the bootblock: 1.216 +# Segments are as follows: %ds = %ss = INITSEG 1.217 + 1.218 +#ifdef BZIMAGE 1.219 + popw %bx 1.220 + popw %si // SYSSEG:0 1.221 +movesys: // %bx = DS, %si 1.222 + movw $16, %ax 1.223 + mulw %bx 1.224 + addw %si, %ax 1.225 + adcw $0x9300, %dx // %dx:%ax src flat address 1.226 + movw $9, %cx 1.227 +zero1: 1.228 + pushw $0 // 2E..1E 1.229 + loop zero1 1.230 + //pushl $0x93100000 // 1A: dest 1.231 + pushw $0x9310 1.232 + pushw %cx 1.233 + pushw $-1 // 18 1.234 + pushw %cx // 16 1.235 + pushw %dx // src 1.236 + pushw %ax 1.237 + pushw $-1 // 10 1.238 + movb $8, %cl 1.239 + movw %cx, %bx // will move 8*64 = 512Kb 1.240 +zero2: 1.241 + pushw $0 // 0E..00 1.242 + loop zero2 1.243 + movw %sp, %si 1.244 + pushw %ss 1.245 + popw %es 1.246 + pushw %es 1.247 + popw %ds 1.248 +syslp: 1.249 + movb $0x80, %ch 1.250 + movb $0x87, %ah 1.251 + int $0x15 1.252 + incb 0x14(%si) 1.253 + incb 0x1C(%si) 1.254 + decw %bx 1.255 + jne syslp 1.256 +#endif 1.257 +jmp_setup: 1.258 + cli 1.259 + ljmp $SETUPSEG, $0 1.260 + 1.261 +#ifdef EXE_SUPPORT 1.262 +#ifdef SHUTDOWNDOS 1.263 +doiret: 1.264 + iret 1.265 +step19: 1.266 + pushw %si 1.267 + pushw %ds 1.268 + movw %sp, %si 1.269 + ldsw %ss:4(%si), %si 1.270 + cmpw $0x19CD, (%si) 1.271 + popw %ds 1.272 + popw %si 1.273 + jne doiret 1.274 + xorw %si, %si 1.275 + movw %si, %ds 1.276 + pushw %cs 1.277 + popw %ss 1.278 + movw $stacktop-4-16, %sp 1.279 +#ifdef ONLY8086 1.280 + popw 4(%si) 1.281 + popw 4+2(%si) 1.282 + popw %bp 1.283 + popw %di 1.284 + popw %si 1.285 + popw %dx 1.286 + popw %cx 1.287 + popw %bx 1.288 + popw %ax 1.289 +#else 1.290 + popl 4(%si) 1.291 + popaw 1.292 +#endif 1.293 +#ifdef BZIMAGE 1.294 + jmp movesys 1.295 +#endif 1.296 +#endif 1.297 +#ifndef BZIMAGE 1.298 +movesys: // %ax = SYSSEG, %bx = DS, %si 1.299 + shrclw $4, %si 1.300 + addw %si, %bx 1.301 +#ifdef TINY_ZIMAGE 1.302 + movw $0xFFFF, %cx 1.303 + xorw %si, %si 1.304 + xorw %di, %di 1.305 + cmpw %ax, %bx 1.306 + jnc forward 1.307 + decw %si 1.308 + decw %di 1.309 + std 1.310 +forward: 1.311 + movw %ax, %es 1.312 + movw %bx, %ds 1.313 + rep 1.314 + movsb 1.315 + cld 1.316 +#else 1.317 + subw %ax, %bx 1.318 + jnc forward 1.319 + movb $0x90, %ah 1.320 + ;decw %ax 1.321 +forward: 1.322 + movw %ax, %es 1.323 + movw %ax, %di 1.324 + addw %bx, %di 1.325 + movw %di, %ds 1.326 + sbbw %di, %di // %di = 0 : -1 1.327 + cmc // C = 1 : 0 1.328 + adcw %di, %ax 1.329 + xorw %si, %si 1.330 + xorw %di, %di 1.331 + movb $0x10, %cl 1.332 + cmpb %cl, %ah // move 512k 1.333 + rep 1.334 + movsb 1.335 + jns forward 1.336 +#endif 1.337 +#ifndef NO_CURSOR_DEFINITION 1.338 + movb $1, %ah 1.339 + movb $0, %bh 1.340 + movb $0x20, %ch // 0x2000 1.341 + int $0x10 1.342 +#endif 1.343 + pushw %ss 1.344 + popw %ds 1.345 + jmp jmp_setup 1.346 +#endif 1.347 +comstart: 1.348 + cld # assume nothing 1.349 +#ifdef ONLY8086 1.350 + movw $INITSEG, %ax 1.351 + pushw %ax 1.352 +#else 1.353 + pushw $INITSEG 1.354 +#endif 1.355 + popw %es 1.356 +#ifdef CMDLINE 1.357 + movw %sp, %di 1.358 + movw $0x80, %si 1.359 + lodsb 1.360 + cbw 1.361 + xchgw %ax, %cx 1.362 + jcxz nocmdline 1.363 +# if defined(BZIMAGE) && BZIMAGE >= 0x202 1.364 + movw $INITSEG/16+stacktop/256, EXEADRS(cmd_line_ptr+1) 1.365 +# else 1.366 + movw $0xA33F, 0x7F(%si) 1.367 +# endif 1.368 +# ifndef NO_CMDLINE_SHRINK 1.369 +skipspace: 1.370 + lodsb 1.371 + cmpb $0x20, %al 1.372 + je skipspace 1.373 +# ifndef NO_CMDLINE_FILE 1.374 + movw %si,%dx 1.375 + decw %si 1.376 + subb $'@',%al 1.377 + jne notafile 1.378 + movb $0x3D,%ah 1.379 + int $0x21 1.380 + jc notafile 1.381 + xchgw %ax,%bx 1.382 + //movw %si,%dx // ~320 bytes max 1.383 + movw $EXEADRS(notafile)-130,%cx 1.384 + movb $0x3F,%ah 1.385 + int $0x21 1.386 + xchgw %ax,%cx 1.387 +notafile: 1.388 +# else 1.389 + decw %si 1.390 +# endif 1.391 +# endif 1.392 + rep 1.393 + movsb 1.394 +nocmdline: 1.395 + orb EXEADRS(setup_sects), %ch 1.396 +# ifndef NO_MINSETUP 1.397 +# ifndef BZIMAGE 1.398 + jnz setupok 1.399 + mov $4, %ch 1.400 +setupok: 1.401 +# endif 1.402 +# endif 1.403 +#else 1.404 + movb EXEADRS(setup_sects), %ch 1.405 +#endif 1.406 + movb $(512-(end_header-_start))/2, %cl 1.407 + movw $0x100, %si 1.408 + movw $end_header, %di 1.409 + rep 1.410 + movsw 1.411 + movw $SYSSEG, %ax 1.412 + movw %ds, %bx 1.413 + pushw %es 1.414 + popw %ss 1.415 +#ifndef SHUTDOWNDOS 1.416 + pushw %es 1.417 + pushw $movesys 1.418 +#endif 1.419 +#ifdef VCPI 1.420 + pushaw 1.421 + smsww %ax 1.422 + andb $1, %al 1.423 + je isrm 1.424 + movw $EXEADRS(gdt_vcpi),%si 1.425 + movw $pagebuf-0x90000,%di // %es = 0x9000 1.426 + movl $pagebuf+3,%es:0x1000(%di) 1.427 +call_vcpi: 1.428 + movb $0xDE,%ah // DE01, EBX = getiface(DS:SI, ES:DI) 1.429 + int $0x67 1.430 + movl $FLAT20(sw2pm_params),%esi 1.431 + movb $0x0C,%al // DE0C switchpm(ESI) 1.432 + jmp call_vcpi 1.433 +pm_code: 1.434 + movl %cr0,%eax 1.435 + andl $0x7FFFFFFE,%eax 1.436 + movl %eax,%cr0 1.437 + movl %eax,%cr3 1.438 +isrm: 1.439 +# ifdef SHUTDOWNDOS 1.440 + trace_int19 1.441 +# else 1.442 + lssw %cs:EXEADRS(saved_ss_sp),%sp 1.443 + popaw 1.444 + retf 1.445 +# endif 1.446 +#else 1.447 +# ifdef SHUTDOWNDOS 1.448 +# ifdef ONLY8086 1.449 + pushw %ax 1.450 + pushw %bx 1.451 + pushw %cx 1.452 + pushw %dx 1.453 + pushw %si 1.454 + pushw %di 1.455 + pushw %bp 1.456 +# else 1.457 + pushaw 1.458 +# endif 1.459 + trace_int19 1.460 +# endif 1.461 + retf 1.462 +#endif 1.463 +#endif 1.464 + 1.465 +# read_sectors reads %di sectors into %es:0 buffer. 1.466 +# %es:0 is updated to the next memory location. 1.467 +# First, sectors are read sector by sector until 1.468 +# sector per track count is known. Then they are 1.469 +# read track by track. 1.470 +# Assume no error on first track. 1.471 + 1.472 +#ifdef FLOPPY_1440K_ONLY 1.473 +#ifndef FLOPPY_HAS_2_SIDES 1.474 +#define FLOPPY_HAS_2_SIDES hardcore heads count to 2 1.475 +#endif 1.476 +#define FLOPPY_SECTORS 18 /* 18 sectors */ 1.477 +#else 1.478 +#define FLOPPY_HEADS 2 /* 2 heads minimum */ 1.479 +#endif 1.480 + 1.481 +return: 1.482 +#ifndef NO_DOTS 1.483 + movw $0xE2E,%ax 1.484 + int $0x10 1.485 +#endif 1.486 + ret 1.487 + 1.488 +check_limits: 1.489 +#ifndef FLOPPY_1440K_ONLY 1.490 + popw %dx 1.491 + cmpb %al, %cl # max sector known ? 1.492 + ja next_head # no -> store it 1.493 +#ifndef FLOPPY_HAS_2_SIDES 1.494 +#ifdef FLOPPY_HEADS 1.495 + cmpb $FLOPPY_HEADS, %dh # 2 heads minimum 1.496 + jb check_cylinder 1.497 +#endif 1.498 + cmpb %ah, %dh # max head known ? 1.499 + ja next_cylinder # no -> store it 1.500 +check_cylinder: 1.501 +#endif 1.502 + pushw %ax 1.503 + cbw # %ah = 0 1.504 +#else 1.505 + pushw %dx 1.506 +#endif 1.507 + int $0x13 # reset controler 1.508 +#ifndef FLOPPY_1440K_ONLY 1.509 + popw %ax 1.510 + movb $1, %al # sector by sector... 1.511 +#else 1.512 + movw $1, %ax 1.513 + jmp more1trk 1.514 +#endif 1.515 +read_sectorslp: 1.516 + pushw %dx # some bios break dx... 1.517 +#ifndef FLOPPY_1440K_ONLY 1.518 + pushw %ax # limits 1.519 + subb %cl, %al # sectors remaining in track 1.520 + ja tolastsect 1.521 + movb $1, %al # first track sector by sector 1.522 +tolastsect: 1.523 +#else 1.524 + movb $FLOPPY_SECTORS+1, %al 1.525 + subb %cl, %al # sectors remaining in track 1.526 +#endif 1.527 + cbw 1.528 + cmpw %di, %ax 1.529 + jb more1trk 1.530 + movw %di, %ax # sectors to read 1.531 +more1trk: 1.532 + pushw %ax # save context 1.533 + movb $2, %ah # cmd: read chs 1.534 + int $0x13 1.535 +#ifndef FLOPPY_1440K_ONLY 1.536 + popw %dx # save %ax 1.537 + popw %ax # limits 1.538 +#else 1.539 + popw %ax # restore context 1.540 + popw %dx 1.541 +#endif 1.542 + jc check_limits 1.543 +#ifndef FLOPPY_1440K_ONLY 1.544 + xchgw %ax, %bp 1.545 + addw %dx,%cx # next sector 1.546 + movw %cx, %si 1.547 + pushw %dx 1.548 + shlclw $5, %dx 1.549 + movw %es, %cx 1.550 + addw %dx, %cx 1.551 + popw %dx 1.552 + subw %dx,%di # update sector counter 1.553 + popw %dx 1.554 +#else 1.555 + addw %ax,%cx # next sector 1.556 + movw %cx, %si 1.557 + pushw %ax 1.558 + shlclw $5, %ax 1.559 + movw %es, %cx 1.560 + addw %ax, %cx 1.561 + popw %ax 1.562 + subw %ax,%di # update sector counter 1.563 +#endif 1.564 +read_sectorsCX: 1.565 + movw %cx, %es # next location 1.566 + jz return 1.567 +read_sectors: 1.568 + movw %si, %cx 1.569 +#ifndef FLOPPY_1440K_ONLY 1.570 +# al is last sector+1 1.571 +# ah is last head+1 1.572 + xchgw %ax, %bp 1.573 +#endif 1.574 +#ifndef FLOPPY_1440K_ONLY 1.575 + cmpb %al,%cl # reach sector limit ? 1.576 + jne bdendlp 1.577 +next_head: 1.578 + movb %cl,%al 1.579 +#else 1.580 + cmpb $FLOPPY_SECTORS+1,%cl # reach sector limit ? 1.581 + jne bdendlp 1.582 +#endif 1.583 + movb $1,%cl # first sector 1.584 +#ifndef FLOPPY_HAS_2_SIDES 1.585 + incb %dh # next head 1.586 + cmpb %ah, %dh # reach head limit ? 1.587 + jne bdendlp 1.588 +next_cylinder: 1.589 + movb %dh,%ah 1.590 + movb $0,%dh # first head 1.591 +#else 1.592 + xorb %cl,%dh # next head 1.593 + jne bdendlp # reach head limit ? 1.594 +#endif 1.595 +# NOTE : support 256 cylinders max 1.596 + incb %ch # next cylinder 1.597 +read_first_sectors: 1.598 +bdendlp: 1.599 + jmp read_sectorslp 1.600 + 1.601 +#ifdef VCPI 1.602 +pagebuf = 0x98000 1.603 +tss = gdt_abs-40 1.604 +gdt = gdt_abs-32 1.605 +gdt_null = gdt_abs-32 1.606 +gdt_vcpi = gdt_abs-24 1.607 +gdt_vcpi2 = gdt_abs-16 1.608 +gdt_vcpi3 = gdt_abs-8 1.609 +gdt_abs: 1.610 + .word 0xFFFF 1.611 + .long 0x92000000 1.612 + .byte 0xCF,0 1.613 +gdt_code: 1.614 + .word 0xFFFF 1.615 +gdt_code_base: 1.616 + .long 0x9A000000+FLAT20(0) 1.617 + .byte 0x8F,0 1.618 +gdt_tss: 1.619 + .word 0x00FF 1.620 +gdt_tss_base: 1.621 + .long 0x89000000+FLAT20(tss) 1.622 + .byte 0,0 1.623 +gdtr: 1.624 +gdt_lim: 1.625 + .word 0xFFFF 1.626 +gdt_base: 1.627 + .long FLAT20(gdt) 1.628 +sw2pm_params: 1.629 +sw2pm_cr3: 1.630 + .long pagebuf+0x1000 1.631 +sw2pm_gdtr_ptr: 1.632 + .long FLAT20(gdtr) 1.633 +sw2pm_idtr_ptr: 1.634 + .long FLAT20(idtr) 1.635 +sw2pm_ldtr: 1.636 + .word 0 1.637 +sw2pm_tr: 1.638 +SEL_TSS = gdt_tss-gdt_null 1.639 + .word SEL_TSS 1.640 +sw2pm_jumpaddr: 1.641 + .long pm_code 1.642 +SEL_CODE = gdt_code-gdt_null 1.643 + .word SEL_CODE 1.644 +idtr: 1.645 +idt_lim: 1.646 + .word 0x03FF 1.647 +idt_base: 1.648 + .long 0 1.649 +# ifndef SHUTDOWNDOS 1.650 +saved_ss_sp: 1.651 + .word stacktop-4-16-4,INITSEG 1.652 +# endif 1.653 +#endif 1.654 +#ifdef ELKS 1.655 + .org 0x1E3 1.656 + .byte 13,10,7 1.657 + .asciz "ELKS Boot" 1.658 +#endif