2020-10-13 22:10:23 +02:00
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section .bss
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; default drive if field in FCB = 0
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defdrv: resb 1
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section .text
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; Functions here generally expect the FCB to be at ES:BX
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; Helper function: read the drive number from FCB,
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; apply default if necessary,
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; and make it current I/O drive
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setdrv: mov dl, [es:bx+fcb.drive] ; A=1
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test dl, dl
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jnz .nofix
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mov dl, [defdrv] ; A=0
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inc dl
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mov [es:bx+fcb.drive], dl ; A=1
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; now set as current i/o drive
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.nofix: dec dl ; A=0 for dsksel
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2020-12-16 00:29:35 +01:00
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jmp logdrv
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2020-10-11 23:33:01 +02:00
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; FCB open
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fcbopn: ; call fcbfst
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; copy match
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; store cluster number in fcb
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; record = 0
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ret
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; FCB close
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fcbcls: ; flush disk buffer
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ret
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; FCB find first
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2020-10-13 22:10:23 +02:00
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fcbfst: mov word [es:bx+fcb.dirpos], 0
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2020-10-11 23:33:01 +02:00
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; FCB find next
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2020-10-13 22:10:23 +02:00
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fcbnxt: call setdrv
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; load rootdir sector from state
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2020-10-11 23:33:01 +02:00
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; search until next match
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; next sec & loop if mismatch
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; err exit if no further matches
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ret
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; FCB delete file
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fcbdel: ; call fcbfst
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; get search state, load root dir from there
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; mark file as deleted
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2020-10-13 22:10:23 +02:00
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; mark buffer dirty
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2020-10-11 23:33:01 +02:00
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ret
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; FCB read
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; read sector from cluster into diskbuf
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fcbrd: ; read record from sector
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; advance record num, carry over to cluster
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ret
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; FCB write
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fcbwr: ; read sector from cluster into diskbuf
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; write record into sector
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; mark buffer dirty
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; advance record num, carry over to cluster
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ret
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; FCB create
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fcbcre:
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ret
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; FCB rename
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fcbren:
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ret
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