wok-6.x annotate syslinux/stuff/iso2exe/bootiso.S @ rev 17454

syslinux/iso2exe: create a vfat partition in usb bootkey (DOS case only)
author Pascal Bellard <pascal.bellard@slitaz.org>
date Thu Dec 18 11:42:27 2014 +0100 (2014-12-18)
parents 3e7ad70145ce
children 9a40226bee2e
rev   line source
pascal@13691 1 .text
pascal@13691 2 .code16
pascal@13691 3 .org 0
pascal@13691 4
pascal@13691 5 CODESZ = 0x8000 // 16 sectors = 32Kb
pascal@13972 6 #define EXEADRS(x) x+0xC0
pascal@14261 7 #define EXELOC(x) x-0x40
pascal@14261 8 #define EXESTR(x) x-0x7F40
pascal@13691 9
pascal@13691 10 .globl _start
pascal@13691 11 _start:
pascal@13691 12 decw %bp // Magic number: MZ
pascal@13691 13 popw %dx
pascal@13972 14 jmp start0 // Bytes on last page of file
pascal@13691 15 .word (CODESZ+511)/512 // Pages in file
pascal@13691 16 .word 0 // Relocations
pascal@13691 17 .word (end_header-_start)/16 // Size of header in paragraphs
pascal@13691 18 .word 4064-(CODESZ/16) // Minimum extra paragraphs needed
pascal@13691 19 .word 4064-(CODESZ/16) // Maximum extra paragraphs needed
pascal@13691 20 .word 0xFFF0 // Initial (relative) SS value
pascal@13691 21 .word 0xFFFE // Initial SP value
pascal@13691 22 .word 0 // Checksum
pascal@13729 23 .word EXEADRS(exestart) // Initial IP value
pascal@13691 24 .word 0xFFF0 // Initial (relative) CS value
pascal@13972 25 initramfssize:
pascal@13972 26 .word 0 // File address of relocation table
pascal@13972 27 id:
pascal@13691 28 .word 0 // Overlay number
pascal@14257 29 fdcnt:
pascal@14257 30 .byte 0 // Bootstrap floppy sector count
pascal@13691 31
pascal@13691 32 /////////////////////// Master Boot Record code //////////////////////////////
pascal@13691 33
pascal@13972 34 start0: // File address of relocation table
pascal@13691 35 pushw %dx // restore SP
pascal@13972 36 incw %bp // restore %bp
pascal@13713 37 pushw $0
pascal@13713 38 popw %ds
pascal@13713 39 movw $0x7C00, %bx
pascal@13713 40 pushfw
pascal@13713 41 pushw %ds
pascal@13713 42 pushw %bx
pascal@13691 43 pushaw
pascal@13691 44 movw %sp, %bp
pascal@13691 45 pushw %es
pascal@13972 46 cld
pascal@13972 47 pushw %ds
pascal@13972 48 popw %es
pascal@13691 49 call setreg
pascal@13691 50 rep
pascal@13691 51 movsw
pascal@13972 52 movw $0x80, %dx
pascal@13691 53 ljmp $0, $0x0600+start2
pascal@13972 54
pascal@13972 55 .org 60
pascal@14261 56 .long 0x0080 // PE header offset
pascal@13972 57 end_header:
pascal@13972 58 chksum:
pascal@13972 59 .word 0
pascal@13972 60 comstart:
pascal@13972 61 .word 0
pascal@13691 62
pascal@14261 63 readsectorX:
pascal@14261 64 movb $0, %cl
pascal@13699 65 readsector1:
pascal@13699 66 movw %cx, (%bx)
pascal@13699 67 incw %cx
pascal@13699 68 movw $0x201, %ax
pascal@13699 69 int $0x13
pascal@13691 70 setreg:
pascal@13699 71 movw %bx, %si
pascal@13691 72 movw $0x0600, %di
pascal@13691 73 movw $0x0100, %cx
pascal@13691 74 return:
pascal@13691 75 ret
pascal@13691 76 start2:
pascal@13691 77 dxloop:
pascal@13699 78 call readsector1
pascal@13691 79 repe
pascal@13691 80 cmpsw
pascal@13691 81 je dxfound
pascal@13691 82 next:
pascal@13699 83 xorw %cx, %cx
pascal@13699 84 xchgw %ax, %dx
pascal@13699 85 addb $0x7D, %al // try every hard disk
pascal@13699 86 andb $0x83, %al // and floppy disk
pascal@13699 87 cmpb $0x80, %al
pascal@13699 88 xchgw %ax, %dx
pascal@13691 89 jnz dxloop
pascal@13691 90 dxfound:
pascal@13691 91 movw %dx, 10(%bp)
pascal@14267 92 call checkboot
pascal@14267 93 noboot:
pascal@14267 94 .ascii "No isolinux mbr."
pascal@14267 95 noboot_end:
pascal@14267 96
pascal@14267 97 .org 0x0080
pascal@14267 98 ////////////////////////////// EXE/PE header //////////////////////////////////
pascal@14267 99
pascal@14267 100 .org 0x01A0
pascal@14267 101 checkboot:
pascal@14261 102 call readsectorX
pascal@13699 103 lodsw
pascal@14267 104 popw %si
pascal@13713 105 shrw $1, %ax
pascal@14267 106 jz error // read fail or not isohydrid
pascal@13691 107 popw %es
pascal@13691 108 popa
pascal@13713 109 iret
pascal@13691 110
pascal@14267 111 error:
pascal@14267 112 movw $noboot_end-noboot, %cx
pascal@14267 113 putsloop:
pascal@14267 114 lodsb
pascal@14267 115 movw $7, %bx
pascal@14267 116 movb $0xE, %ah
pascal@14267 117 int $0x10
pascal@14267 118 loop putsloop
pascal@14267 119 halt:
pascal@14267 120 hlt
pascal@14267 121 jmp halt
pascal@14267 122 .org 0x01BE
pascal@14261 123
pascal@14261 124 .org 0x7EE0
pascal@13691 125 ////////////////////////////// DOS EXE code ///////////////////////////////////
pascal@13691 126
pascal@13729 127 exestart:
pascal@13699 128 cld
pascal@13697 129 movw $0x100, %si
pascal@17160 130 movw -126(%si), %ax
pascal@13729 131 cwd // clear dx
pascal@17454 132 pushw %dx // dos exit()
pascal@17160 133 cmpb $0x2F, %al
pascal@17160 134 movw $0x3000+EXESTR(help), %ax
pascal@17454 135 je abort
pascal@17454 136 int $0x21 // get DOS version
pascal@17160 137 cmpb $3, %al
pascal@17160 138 movb $EXESTR(noDOS3), %al
pascal@17160 139 jb abort
pascal@13729 140 #if 1
pascal@17160 141 cmpw (%si), %dx // checksum not set
pascal@17160 142 je chked
pascal@13729 143 #endif
pascal@14261 144 movw $(EXELOC(0x8000))/2, %cx
pascal@13697 145 chklp:
pascal@13697 146 lodsw
pascal@13697 147 addw %ax, %dx
pascal@13697 148 loop chklp
pascal@17160 149 chked:
pascal@17160 150 movw $0x1000+EXESTR(chkerr), %ax
pascal@17160 151 je tst386 // dx == 0 ?
pascal@13691 152 abort:
pascal@13691 153 puts:
pascal@14261 154 movb $0x80, %ah
pascal@13713 155 xchgw %ax, %si
pascal@13713 156 putslp:
pascal@13713 157 lodsb
pascal@13713 158 orb %al, %al
pascal@13713 159 jz moveret
pascal@13713 160 js puts
pascal@13713 161 movw $7, %bx
pascal@13713 162 movb $0xE, %ah
pascal@13713 163 int $0x10
pascal@13713 164 jmp putslp
pascal@13691 165
pascal@17160 166 tst386:
pascal@17160 167 pushfw // save flags
pascal@17160 168 // bits 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
pascal@17160 169 // flags 0 NT IOPL OF DF IF TF SF ZF 0 AF 0 PF 1 CF
pascal@17160 170 // movb $0x10, %ah
pascal@17160 171 pushw %ax
pascal@17160 172 popfw // < 286 : flags[12..15] are forced 1
pascal@17160 173 pushfw // = 286 : flags[12..15] are forced 0
pascal@17160 174 popw %bx // > 286 : only flags[15] is forced 0
pascal@17454 175 popfw // restore flags (IOPL)
pascal@17160 176 addb %ah, %bh // test F0 and 00 cases
pascal@17160 177 cmpb %ah, %bh
pascal@17160 178 movb $EXESTR(no386), %al
pascal@17160 179 #undef NEED386
pascal@17160 180 #ifdef NEED386
pascal@17160 181 jbe abort // C=8086/80186, Z=80286
pascal@17160 182 #else
pascal@17160 183 jbe is86 // C=8086/80186, Z=80286
pascal@17160 184 #endif
pascal@13691 185 is386:
pascal@17160 186 smsww %ax // not privileged
pascal@13691 187 andb $1, %al
pascal@13691 188 jne tstvcpi
pascal@17160 189 movl %cr0, %eax // privileged
pascal@14150 190 incl %eax
pascal@13713 191 movb $EXESTR(rmPaging), %al
pascal@14150 192 js abort
pascal@13713 193 movb $EXESTR(realmodemsg), %al
pascal@13691 194 realmode:
pascal@17160 195 is86:
pascal@13691 196 call puts
pascal@13691 197 movw $0x0100, %di
pascal@14261 198 movw comstart-end_header(%di), %si // .com address
pascal@13691 199 pushw %di
pascal@14261 200 movb $0x7D, %ch
pascal@13691 201 rep
pascal@13691 202 movsb
pascal@13713 203 moveret:
pascal@13691 204 ret
pascal@13713 205
pascal@13713 206 VersionVCPI:
pascal@13713 207 cmpb $0x40, %dl // >= 4.0 ?
pascal@13713 208 jb NoVCPI
pascal@13713 209 movb $EXESTR(vm86modemsg), %al
pascal@13713 210 jmp realmode
pascal@13713 211 tstvcpi:
pascal@13713 212 pushw %ds
pascal@17160 213 movw %dx, %ds // %dx = 0
pascal@13713 214 movw 0x67*4+2, %ds
pascal@13713 215 movw $10, %si
pascal@14150 216 lodsl
pascal@13713 217 xorw $0x4D45, %ax // EM(MX) or EM(MQ)
pascal@14150 218 lodsl
pascal@13713 219 popw %ds
pascal@14150 220 jne NoVCPI
pascal@14150 221 xorl $0x30585858, %eax // XXX0
pascal@13713 222 movw $EXEADRS(CmdVCPI), %si
pascal@13713 223 ChkVCPI:
pascal@13713 224 NoVCPI:
pascal@13713 225 movb $EXESTR(ERRvcpi), %al
pascal@13713 226 jne abort
pascal@13713 227 lodsb
pascal@13713 228 shlw $8, %ax
pascal@13713 229 je VersionVCPI
pascal@13713 230 int $0x67
pascal@13713 231 testb %ah, %ah
pascal@14150 232 xchgw %ax, %dx
pascal@13713 233 jmp ChkVCPI
pascal@13713 234 CmdVCPI:
pascal@13713 235 .byte 0x40 // status
pascal@13713 236 .byte 0xDE // vcpi present ?
pascal@13713 237 .byte 0x46 // version
pascal@13713 238 .byte 0
pascal@13713 239
pascal@14261 240 // -------------------------------------------------------------------
pascal@13691 241
pascal@14261 242 help:
pascal@14261 243 .ascii "SliTaz GNU/L" // SliTaz GNU/Linux boot loader
pascal@14261 244 .byte EXESTR(iloader)
pascal@14261 245 no386:
pascal@14261 246 .ascii "No 386" // No 386+
pascal@14261 247 .byte EXESTR(plus)
pascal@14261 248 ERRvcpi:
pascal@14261 249 .ascii "No EMM386/VCPI 4" // No EMM386/VCPI 4.0+
pascal@14261 250 .byte EXESTR(dot0)
pascal@14261 251 chkerr:
pascal@17160 252 .ascii "Broken ISO9660 fil" // Broken ISO9660 file.
pascal@14261 253 .byte EXESTR(eeol)
pascal@14261 254 vm86modemsg:
pascal@14261 255 .ascii "vm86" // vm86 mode.
pascal@14261 256 .byte EXESTR(mode)
pascal@14261 257 rmPaging:
pascal@14261 258 .ascii "Invalid: paging + " // Invalid: paging + real mode.
pascal@14261 259 realmodemsg:
pascal@14261 260 .ascii "real" // real mode.
pascal@14261 261 // --------------- Must be in 00C0 013F range ------------------------
pascal@14261 262 mode:
pascal@14261 263 .ascii " mod"
pascal@14261 264 eeol:
pascal@14261 265 .ascii "e"
pascal@14261 266 .byte EXESTR(eol)
pascal@14261 267 //noloader:
pascal@14261 268 // .ascii "No isol" // No isolinux boot loader
pascal@14261 269 iloader:
pascal@14261 270 .ascii "inux boot loader"
pascal@14261 271 eol:
pascal@14261 272 .ascii "."
pascal@14261 273 eol2:
pascal@14261 274 .asciz "\r\n"
pascal@14261 275 noDOS3:
pascal@14261 276 .ascii "No DOS 3" // No DOS 3.0+
pascal@14261 277 dot0:
pascal@14261 278 .ascii ".0"
pascal@14261 279 plus:
pascal@14261 280 .ascii "+"
pascal@14261 281 .byte EXESTR(eol2)
pascal@14261 282
pascal@14261 283 .org 0x8000
pascal@14261 284 ////////////////////////// ISO9660 header /////////////////////////////////////
pascal@14261 285