wok-6.x annotate syslinux/stuff/iso2exe/bootiso.S @ rev 19871

linld/tazboot: fix magic
author Pascal Bellard <pascal.bellard@slitaz.org>
date Thu Mar 30 17:22:13 2017 +0200 (2017-03-30)
parents e6f0efe26374
children f01ec3e34a08
rev   line source
pascal@13691 1 .text
pascal@13691 2 .code16
pascal@19828 3 .arch i8086
pascal@13691 4 .org 0
pascal@13691 5
pascal@13691 6 CODESZ = 0x8000 // 16 sectors = 32Kb
pascal@13972 7 #define EXEADRS(x) x+0xC0
pascal@14261 8 #define EXELOC(x) x-0x40
pascal@14261 9 #define EXESTR(x) x-0x7F40
pascal@13691 10
pascal@13691 11 .globl _start
pascal@13691 12 _start:
pascal@13691 13 decw %bp // Magic number: MZ
pascal@13691 14 popw %dx
pascal@13972 15 jmp start0 // Bytes on last page of file
pascal@13691 16 .word (CODESZ+511)/512 // Pages in file
pascal@13691 17 .word 0 // Relocations
pascal@13691 18 .word (end_header-_start)/16 // Size of header in paragraphs
pascal@13691 19 .word 4064-(CODESZ/16) // Minimum extra paragraphs needed
pascal@13691 20 .word 4064-(CODESZ/16) // Maximum extra paragraphs needed
pascal@13691 21 .word 0xFFF0 // Initial (relative) SS value
pascal@13691 22 .word 0xFFFE // Initial SP value
pascal@13691 23 .word 0 // Checksum
pascal@13729 24 .word EXEADRS(exestart) // Initial IP value
pascal@13691 25 .word 0xFFF0 // Initial (relative) CS value
pascal@13972 26 initramfssize:
pascal@13972 27 .word 0 // File address of relocation table
pascal@17810 28 fdcnt: // Overlay number
pascal@14257 29 .byte 0 // Bootstrap floppy sector count
pascal@17810 30 .ascii "slitaz"
pascal@13691 31
pascal@13691 32 /////////////////////// Master Boot Record code //////////////////////////////
pascal@13691 33
pascal@17810 34 moved = 0x8000
pascal@17496 35 start0:
pascal@19827 36 //pushw %dx // restore %sp
pascal@19827 37 //incw %bp // restore %bp
pascal@17496 38 xorw %bx, %bx
pascal@17496 39 movw %bx, %ds
pascal@17496 40 movb $0x7C, %bh
pascal@19827 41 pushw %ds
pascal@19827 42 popw %ss
pascal@19827 43 movw %bx, %sp
pascal@17496 44 pushw %bx // return address
pascal@19827 45 pushw %di
pascal@17496 46 pushw %es // save %es:%di
pascal@13972 47 cld
pascal@17496 48 sti
pascal@13972 49 pushw %ds
pascal@13972 50 popw %es
pascal@13691 51 call setreg
pascal@13691 52 rep
pascal@19827 53 movsw
pascal@13972 54 movw $0x80, %dx
pascal@17810 55 ljmp $0, $moved+start2
pascal@17810 56 .byte 0
pascal@17810 57 // .org 60
pascal@17810 58 // .long 0x0080 // PE header offset
pascal@17810 59 .org 64
pascal@13972 60 end_header:
pascal@13972 61 comstart:
pascal@13972 62 .word 0
pascal@13691 63
pascal@17810 64 .org 66
pascal@17810 65 dxloop:
pascal@17810 66 start2:
pascal@17810 67 call readsector1 // look for the boot device
pascal@17810 68 repe
pascal@17810 69 cmpsw
pascal@17810 70 je dxfound
pascal@17810 71 movb $0, %cl // ch = 0
pascal@17810 72 addb $0x7D, %dl // try every hard disk
pascal@17810 73 jno dxloop
pascal@17810 74
pascal@17810 75 dxfound:
pascal@17810 76 call readsectorX // read isolinux boot sector
pascal@17810 77 cmpw (%bx), %cx
pascal@17810 78 jnc puts // read fail or no isohydrid boot sector
pascal@19827 79 movw $patch,%si
pascal@17810 80 popw %es
pascal@19827 81 popw %di // isolinux boot needs %es:%di and %dx
pascal@17810 82 putsret:
pascal@17810 83 ret
pascal@17810 84
pascal@17810 85 putstrlp:
pascal@17810 86 movw $7, %bx
pascal@17810 87 movb $0xE, %ah
pascal@17810 88 int $0x10
pascal@17810 89 error:
pascal@17810 90 lodsb
pascal@17810 91 cmp $1, %al
pascal@17810 92 jg putstrlp
pascal@17810 93 jz putsret
pascal@17810 94 puts:
pascal@17810 95 movb $0x80, %ah
pascal@17810 96 xchgw %ax, %si
pascal@17810 97 jnc error
pascal@17810 98 halt:
pascal@17810 99 hlt
pascal@17810 100 jmp halt
pascal@17810 101 nobsmsg:
pascal@17810 102 .asciz "No isolinux."
pascal@17810 103
pascal@17810 104 .org 0x0080
pascal@17810 105 ////////////////////////////// EXE/PE header //////////////////////////////////
pascal@17810 106
pascal@17810 107 .org 0x01A0
pascal@17496 108 readsectorX: // read isolinux boot sector
pascal@17496 109 movb $0xA5, %cl // patched by installer
pascal@13699 110 readsector1:
pascal@17496 111 andb $0x83, %dl // disk and floppy disk
pascal@13699 112 movw %cx, (%bx)
pascal@13699 113 incw %cx
pascal@13699 114 movw $0x201, %ax
pascal@13699 115 int $0x13
pascal@13691 116 setreg:
pascal@13699 117 movw %bx, %si
pascal@17810 118 movw $moved, %di
pascal@13691 119 movw $0x0100, %cx
pascal@17810 120 movb $nobsmsg, %al
pascal@13691 121 ret
pascal@17810 122 .org 0x01B8
pascal@14267 123
pascal@19827 124 ////////////////////////// partition boot code ////////////////////////////////
pascal@19842 125 // assume DS=SS BX=7C00 CH=01 DL=<drive> SI=7DBE
pascal@19827 126
pascal@19827 127 .org 0x7C00
pascal@19827 128 jmp bootpartition
pascal@19827 129 .org 0x7C03
pascal@19827 130 .org 0x7DBE
pascal@19827 131 table = moved+0x1BE
pascal@19827 132 patch:
pascal@19827 133 .byte 0,0,0 // head of original bs
pascal@19827 134 partcode:
pascal@19837 135 popw %si
pascal@19837 136 xchgw %si,%di
pascal@19827 137 call movepartition
pascal@19837 138 pushw %cx
pascal@19837 139 pushw %cx
pascal@19842 140 decw %di
pascal@19842 141 decw %di
pascal@19827 142 movb $4,%cl
pascal@19842 143 movw $16,%ax
pascal@19827 144 next:
pascal@19842 145 subw %ax,%di
pascal@19827 146 cmpb %ch,(%di) // boot flag ?
pascal@19827 147 loope next
pascal@19828 148 pushw 10(%di)
pascal@19828 149 pushw 8(%di)
pascal@19837 150 pushw %cs
pascal@19827 151 pushw %bx
pascal@19828 152 movb $1,%cl
pascal@19828 153 pushw %cx
pascal@19828 154 pushw %ax
pascal@19827 155 movw %sp,%si // assume %ds = %ss
pascal@19828 156 pushw %bx
pascal@19837 157 cmpw $63,2(%di) // empty or isolinux partition ?
pascal@19828 158 jbe default
pascal@19827 159 movb $0x42,%ah
pascal@19827 160 int $0x13
pascal@19827 161 default:
pascal@19827 162 ret
pascal@19828 163 .org 0x7DF0
pascal@19827 164 bootpartition:
pascal@19827 165 pushw %ds
pascal@19827 166 popw %es
pascal@19827 167 pushw %si
pascal@19827 168 movw %bx,%di
pascal@19827 169 movsw
pascal@19827 170 movsb
pascal@19837 171 movw $table-0x142,%di
pascal@19827 172 pushw %di
pascal@19827 173 movepartition:
pascal@19828 174 movb $66,%cl // 0142 and 0042
pascal@19827 175 rep
pascal@19828 176 movsb
pascal@19827 177 ret
pascal@19827 178 .org 0x7E00
pascal@19827 179
pascal@19870 180 .org 0x7F83
pascal@13691 181 ////////////////////////////// DOS EXE code ///////////////////////////////////
pascal@13691 182
pascal@13729 183 exestart:
pascal@13699 184 cld
pascal@17810 185 movw 129, %ax
pascal@17473 186 cmpb $0x2F, %al
pascal@17473 187 je ishelp
pascal@17473 188 cmpw $0x2F20, %ax
pascal@17473 189 ishelp:
pascal@17473 190 movw $0x3000+EXESTR(help), %ax
pascal@13729 191 cwd // clear dx
pascal@17454 192 pushw %dx // dos exit()
pascal@17454 193 je abort
pascal@17454 194 int $0x21 // get DOS version
pascal@17562 195 addb $-3, %al
pascal@19849 196 movb $EXESTR(noDOS3), %al
pascal@19435 197 movw $0x100, %di
pascal@17810 198 jc tst386
pascal@13691 199 abort:
pascal@19849 200 goputs:
pascal@19849 201 jmp puts
pascal@13691 202
pascal@17160 203 tst386:
pascal@19849 204 pushw %sp
pascal@19849 205 popw %ax
pascal@19870 206 xorw %sp, %ax // clear C
pascal@19870 207 movb $EXESTR(vm86modemsg), %al
pascal@19849 208 jnz is86 // 86/186 not a 286+
pascal@19828 209 .arch i486
pascal@13691 210 is386:
pascal@19870 211 smsww %bx // not privileged
pascal@19870 212 andb $1, %bl // clear C
pascal@19863 213 jne isvm86
pascal@19870 214 movl %cr0, %ebx // privileged
pascal@19870 215 incl %ebx
pascal@19863 216 .arch i8086
pascal@13713 217 movb $EXESTR(rmPaging), %al
pascal@14150 218 js abort
pascal@19870 219 is86:
pascal@19870 220 incw %ax
pascal@17810 221 //movb $EXESTR(realmodemsg), %al
pascal@19863 222 isvm86:
pascal@19849 223 call goputs
pascal@14261 224 movw comstart-end_header(%di), %si // .com address
pascal@13691 225 pushw %di
pascal@17906 226 movb $0x7C/2, %ch // 31K-31.5K, > com length
pascal@13691 227 rep
pascal@17473 228 movsw
pascal@13691 229 ret
pascal@13713 230
pascal@17496 231 vm86modemsg:
pascal@17473 232 // --------------- Must be in 7F40 7FFF range ------------------------
pascal@19871 233 .ascii "v" // v86 mode
pascal@17810 234 .ascii "86" // 86 mode
pascal@17562 235 .byte EXESTR(mode)
pascal@14261 236 rmPaging:
pascal@17810 237 .ascii "X" // Xreal mode
pascal@14261 238 realmodemsg:
pascal@17562 239 .ascii "real" // real mode
pascal@17473 240 // --------------- Must be in 7FC0 7FFF range ------------------------
pascal@17562 241 mode:
pascal@17562 242 .ascii " m"
pascal@17496 243 ode:
pascal@17562 244 .ascii "ode"
pascal@14261 245 .byte EXESTR(eol)
pascal@17562 246 noDOS3:
pascal@17810 247 .ascii "DOS3" // DOS3?
pascal@17562 248 need:
pascal@17810 249 .ascii "?"
pascal@17496 250 .byte EXESTR(eol)
pascal@17473 251 help:
pascal@19435 252 .ascii "SliTaz iso boot." // SliTaz iso boot.
pascal@17473 253 eol:
pascal@17496 254 .ascii "\r\n"
pascal@17810 255 .byte 1 // puts will return
pascal@14261 256
pascal@17496 257 .space 16,0 // ISO md5
pascal@14261 258 .org 0x8000
pascal@14261 259 ////////////////////////// ISO9660 header /////////////////////////////////////