2020-10-30 10:29:22 +01:00
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; Utilities to help with far pointers
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; exchange DS:SI with ES:DI
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xchgs: push ds
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push es
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pop ds
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pop es
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xchg si, di
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ret
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2020-10-25 00:50:23 +02:00
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; far pointer load
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; IN ES:BX far pointer to data
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; CX number of bytes to copy
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; 0:DX destination buffer
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2020-10-30 10:29:22 +01:00
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lod: push es
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2020-10-25 00:50:23 +02:00
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; ES:DI := DS:DX
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mov ax, ds
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mov es, ax
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mov di, dx
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; DS:SI := 0:BX
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xor ax, ax
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mov ds, ax
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mov si, bx
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; copy
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pushf
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cld
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rep movsb
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popf
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; reset DS to kernel data
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mov ds, cx
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pop es
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ret
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; far pointer store
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; IN ES:BX far ptr
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; CX number of bytes
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; 0:DX source buffer
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; only CX is trashed
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2020-10-30 10:29:22 +01:00
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sto: mov si, dx
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2020-10-25 00:50:23 +02:00
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mov di, bx
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cld
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rep movsb
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ret
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