|
Last change
on this file was
e16e8f2,
checked in by Edwin Eefting <edwin@datux.nl>, 3 years ago
|
|
bootstuff
|
-
Property mode set to
100644
|
|
File size:
1.5 KB
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| 1 | FILE_LICENCE ( GPL2_OR_LATER ) |
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| 2 | |
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| 3 | .text |
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| 4 | .arch i386 |
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| 5 | .section ".prefix", "awx", @progbits |
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| 6 | .code16 |
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| 7 | .org 0 |
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| 8 | |
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| 9 | movw $load_image, %bp |
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| 10 | jmp find_active_partition |
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| 11 | |
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| 12 | #include "bootpart.S" |
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| 13 | |
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| 14 | load_image: |
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| 15 | /* Get disk geometry */ |
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| 16 | pushal |
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| 17 | pushw %es |
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| 18 | movb $0x08, %ah |
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| 19 | int $0x13 |
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| 20 | jc load_failed |
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| 21 | movb %cl, max_sector |
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| 22 | movb %dh, max_head |
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| 23 | popw %es |
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| 24 | popal |
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| 25 | |
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| 26 | 1: /* Read to end of current track */ |
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| 27 | movb %cl, %al |
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| 28 | negb %al |
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| 29 | addb max_sector, %al |
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| 30 | incb %al |
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| 31 | andb $0x3f, %al |
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| 32 | movzbl %al, %eax |
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| 33 | call *read_sectors |
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| 34 | jc load_failed |
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| 35 | |
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| 36 | /* Update %es */ |
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| 37 | movw %es, %bx |
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| 38 | shll $5, %eax |
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| 39 | addw %ax, %bx |
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| 40 | movw %bx, %es |
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| 41 | shrl $5, %eax |
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| 42 | |
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| 43 | /* Update LBA address */ |
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| 44 | addl %eax, %edi |
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| 45 | adcl $0, %esi |
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| 46 | |
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| 47 | /* Update CHS address */ |
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| 48 | andb $0xc0, %cl |
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| 49 | orb $0x01, %cl |
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| 50 | incb %dh |
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| 51 | cmpb max_head, %dh |
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| 52 | jbe 2f |
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| 53 | xorb %dh, %dh |
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| 54 | incb %ch |
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| 55 | jnc 2f |
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| 56 | addb $0xc0, %cl |
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| 57 | 2: |
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| 58 | /* Loop until whole image is read */ |
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| 59 | subl %eax, load_length |
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| 60 | ja 1b |
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| 61 | ljmp $BOOT_SEG, $start_image |
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| 62 | |
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| 63 | max_sector: |
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| 64 | .byte 0 |
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| 65 | max_head: |
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| 66 | .byte 0 |
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| 67 | load_length: |
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| 68 | .long 0 |
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| 69 | |
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| 70 | .section ".zinfo.fixup", "a", @progbits /* Compressor fixups */ |
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| 71 | .ascii "ADDL" |
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| 72 | .long load_length |
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| 73 | .long 512 |
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| 74 | .long 0 |
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| 75 | .previous |
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| 76 | |
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| 77 | |
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| 78 | load_failed: |
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| 79 | movw $10f, %si |
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| 80 | jmp boot_error |
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| 81 | 10: .asciz "Could not load gPXE\r\n" |
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| 82 | |
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| 83 | .org 510 |
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| 84 | .byte 0x55, 0xaa |
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| 85 | |
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| 86 | start_image: |
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| 87 | /* Install gPXE */ |
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| 88 | call install |
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| 89 | |
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| 90 | /* Set up real-mode stack */ |
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| 91 | movw %bx, %ss |
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| 92 | movw $_estack16, %sp |
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| 93 | |
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| 94 | /* Jump to .text16 segment */ |
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| 95 | pushw %ax |
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| 96 | pushw $1f |
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| 97 | lret |
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| 98 | .section ".text16", "awx", @progbits |
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| 99 | 1: |
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| 100 | pushl $main |
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| 101 | pushw %cs |
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| 102 | call prot_call |
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| 103 | popl %ecx /* discard */ |
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| 104 | |
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| 105 | /* Uninstall gPXE */ |
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| 106 | call uninstall |
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| 107 | |
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| 108 | /* Boot next device */ |
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| 109 | int $0x18 |
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