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76 lines
1.4 KiB
76 lines
1.4 KiB
#generate 16-bit code
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.code16
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#hint the assembler that here is the executable code located
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.text
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.globl _start;
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#boot code entry
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_start:
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jmp _boot
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start: .asciz "Start.\n\r"
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error: .asciz "Error.\n\r"
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succes: .asciz "Succes.\n\r"
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ffs: .asciz "F.\n\r"
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end: .asciz "End.\n\r"
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.macro mWriteString str #macro which calls a function to print a string
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leaw \str, %si
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call .writeStringIn
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.endm
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# function to print the string
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.writeStringIn:
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lodsb
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orb %al, %al
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jz .writeStringOut
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movb $0x0e, %ah
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int $0x10
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jmp .writeStringIn
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.writeStringOut:
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ret
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_boot:
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mWriteString start
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#This goes first as to now overwrite %ah and %al.
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mov $0x00, %ax
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mov %ax, %es #Section to write into
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mov $0x02, %ah # Read sectors from drive
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mov $0x01, %al # Number of sectors to read
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mov $0x00, %ch # Low 8 bits of cylinder
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mov $0x02, %cl # First sector to read (bits 0-5), upper bits of cylinder (bits 6-7)
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mov $0x00, %dh # Head number
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mov $0x00, %dl # Drive number
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# mov $0x00, %es
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mov $0xFF, %bx #Offset into section
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int $0x13 # Low level disk services
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jnc notcarry
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mWriteString error
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jmp endcarrycheck
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notcarry:
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mWriteString succes
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#fallthrough
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endcarrycheck:
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mWriteString mystr
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mWriteString end
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#
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#move to 510th byte from the start and append boot signature
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. = _start + 510
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.byte 0x55
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.byte 0xaa
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mystr: .asciz "asdf"
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. = _start + 1023
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.byte 0x00
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