;
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;
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; sctio-ctl.s -- disk sector I/O for disk made available by disk controller
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; sctio-ctl.s -- disk sector I/O for disk made available by disk controller
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;
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;
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|
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;***************************************************************
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;***************************************************************
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|
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.set dskbase,0xF0400000 ; disk base address
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.set dskbase,0xF0400000 ; disk base address
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.set dskctrl,0 ; control register
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.set dskctrl,0 ; control register
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.set dskcnt,4 ; count register
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.set dskcnt,4 ; count register
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.set dsksct,8 ; sector register
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.set dsksct,8 ; sector register
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.set dskcap,12 ; capacity register
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.set dskcap,12 ; capacity register
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.set dskbuf,0x00080000 ; disk buffer
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.set dskbuf,0x00080000 ; disk buffer
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|
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.set ctrlstrt,0x01 ; start bit
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.set ctrlstrt,0x01 ; start bit
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.set ctrlien,0x02 ; interrupt enable bit
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.set ctrlien,0x02 ; interrupt enable bit
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.set ctrlwrt,0x04 ; write bit
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.set ctrlwrt,0x04 ; write bit
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.set ctrlerr,0x08 ; error bit
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.set ctrlerr,0x08 ; error bit
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.set ctrldone,0x10 ; done bit
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.set ctrldone,0x10 ; done bit
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.set ctrlrdy,0x20 ; ready bit
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.set ctrlrdy,0x20 ; ready bit
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|
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.set sctsize,512 ; sector size in bytes
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.set sctsize,512 ; sector size in bytes
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|
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.set retries,1000000 ; retries to get disk ready
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.set retries,1000000 ; retries to get disk ready
|
|
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.export sctcapctl ; determine disk capacity
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.export sctcapctl ; determine disk capacity
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.export sctioctl ; do disk I/O
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.export sctioctl ; do disk I/O
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|
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;***************************************************************
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;***************************************************************
|
|
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.code
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.code
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.align 4
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.align 4
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|
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sctcapctl:
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sctcapctl:
|
add $8,$0,retries ; set retry count
|
add $8,$0,retries ; set retry count
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add $9,$0,dskbase
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add $9,$0,dskbase
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sctcap1:
|
sctcap1:
|
ldw $10,$9,dskctrl
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ldw $10,$9,dskctrl
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and $10,$10,ctrlrdy ; ready?
|
and $10,$10,ctrlrdy ; ready?
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bne $10,$0,sctcapok ; yes - jump
|
bne $10,$0,sctcapok ; yes - jump
|
sub $8,$8,1
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sub $8,$8,1
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bne $8,$0,sctcap1 ; try again
|
bne $8,$0,sctcap1 ; try again
|
add $2,$0,0 ; no disk found
|
add $2,$0,0 ; no disk found
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j sctcapx
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j sctcapx
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sctcapok:
|
sctcapok:
|
ldw $2,$9,dskcap ; get disk capacity
|
ldw $2,$9,dskcap ; get disk capacity
|
sctcapx:
|
sctcapx:
|
jr $31
|
jr $31
|
|
|
sctioctl:
|
sctioctl:
|
sub $29,$29,24
|
sub $29,$29,24
|
stw $31,$29,20
|
stw $31,$29,20
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stw $16,$29,16
|
stw $16,$29,16
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stw $17,$29,12
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stw $17,$29,12
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stw $18,$29,8
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stw $18,$29,8
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stw $19,$29,4
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stw $19,$29,4
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stw $20,$29,0
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stw $20,$29,0
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add $16,$4,$0 ; command
|
add $16,$4,$0 ; command
|
add $17,$5,$0 ; sector number
|
add $17,$5,$0 ; sector number
|
add $18,$6,0xC0000000 ; memory address, virtualized
|
add $18,$6,0xC0000000 ; memory address, virtualized
|
add $19,$7,$0 ; number of sectors
|
add $19,$7,$0 ; number of sectors
|
|
|
add $8,$0,'r'
|
add $8,$0,'r'
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beq $16,$8,sctrd
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beq $16,$8,sctrd
|
add $8,$0,'w'
|
add $8,$0,'w'
|
beq $16,$8,sctwr
|
beq $16,$8,sctwr
|
add $2,$0,0xFF ; illegal command
|
add $2,$0,0xFF ; illegal command
|
j sctx
|
j sctx
|
|
|
sctrd:
|
sctrd:
|
add $2,$0,$0 ; return ok
|
add $2,$0,$0 ; return ok
|
beq $19,$0,sctx ; if no (more) sectors
|
beq $19,$0,sctx ; if no (more) sectors
|
add $8,$0,dskbase
|
add $8,$0,dskbase
|
add $9,$0,1
|
add $9,$0,1
|
stw $9,$8,dskcnt ; number of sectors
|
stw $9,$8,dskcnt ; number of sectors
|
stw $17,$8,dsksct ; sector number on disk
|
stw $17,$8,dsksct ; sector number on disk
|
add $9,$0,ctrlstrt
|
add $9,$0,ctrlstrt
|
stw $9,$8,dskctrl ; start command
|
stw $9,$8,dskctrl ; start command
|
sctrd1:
|
sctrd1:
|
ldw $2,$8,dskctrl
|
ldw $2,$8,dskctrl
|
and $9,$2,ctrldone ; done?
|
and $9,$2,ctrldone ; done?
|
beq $9,$0,sctrd1 ; no - wait
|
beq $9,$0,sctrd1 ; no - wait
|
and $9,$2,ctrlerr ; error?
|
and $9,$2,ctrlerr ; error?
|
bne $9,$0,sctx ; yes - leave
|
bne $9,$0,sctx ; yes - leave
|
add $8,$0,dskbase + dskbuf ; transfer data
|
add $8,$0,dskbase + dskbuf ; transfer data
|
add $9,$0,sctsize
|
add $9,$0,sctsize
|
sctrd2:
|
sctrd2:
|
ldw $10,$8,0 ; from disk buffer
|
ldw $10,$8,0 ; from disk buffer
|
stw $10,$18,0 ; to memory
|
stw $10,$18,0 ; to memory
|
add $8,$8,4
|
add $8,$8,4
|
add $18,$18,4
|
add $18,$18,4
|
sub $9,$9,4
|
sub $9,$9,4
|
bne $9,$0,sctrd2
|
bne $9,$0,sctrd2
|
add $17,$17,1 ; increment sector number
|
add $17,$17,1 ; increment sector number
|
sub $19,$19,1 ; decrement number of sectors
|
sub $19,$19,1 ; decrement number of sectors
|
j sctrd ; next sector
|
j sctrd ; next sector
|
|
|
sctwr:
|
sctwr:
|
add $2,$0,$0 ; return ok
|
add $2,$0,$0 ; return ok
|
beq $19,$0,sctx ; if no (more) sectors
|
beq $19,$0,sctx ; if no (more) sectors
|
add $8,$0,dskbase + dskbuf ; transfer data
|
add $8,$0,dskbase + dskbuf ; transfer data
|
add $9,$0,sctsize
|
add $9,$0,sctsize
|
sctwr1:
|
sctwr1:
|
ldw $10,$18,0 ; from memory
|
ldw $10,$18,0 ; from memory
|
stw $10,$8,0 ; to disk buffer
|
stw $10,$8,0 ; to disk buffer
|
add $18,$18,4
|
add $18,$18,4
|
add $8,$8,4
|
add $8,$8,4
|
sub $9,$9,4
|
sub $9,$9,4
|
bne $9,$0,sctwr1
|
bne $9,$0,sctwr1
|
add $8,$0,dskbase
|
add $8,$0,dskbase
|
add $9,$0,1
|
add $9,$0,1
|
stw $9,$8,dskcnt ; number of sectors
|
stw $9,$8,dskcnt ; number of sectors
|
stw $17,$8,dsksct ; sector number on disk
|
stw $17,$8,dsksct ; sector number on disk
|
add $9,$0,ctrlwrt | ctrlstrt
|
add $9,$0,ctrlwrt | ctrlstrt
|
stw $9,$8,dskctrl ; start command
|
stw $9,$8,dskctrl ; start command
|
sctwr2:
|
sctwr2:
|
ldw $2,$8,dskctrl
|
ldw $2,$8,dskctrl
|
and $9,$2,ctrldone ; done?
|
and $9,$2,ctrldone ; done?
|
beq $9,$0,sctwr2 ; no - wait
|
beq $9,$0,sctwr2 ; no - wait
|
and $9,$2,ctrlerr ; error?
|
and $9,$2,ctrlerr ; error?
|
bne $9,$0,sctx ; yes - leave
|
bne $9,$0,sctx ; yes - leave
|
add $17,$17,1 ; increment sector number
|
add $17,$17,1 ; increment sector number
|
sub $19,$19,1 ; decrement number of sectors
|
sub $19,$19,1 ; decrement number of sectors
|
j sctwr ; next sector
|
j sctwr ; next sector
|
|
|
sctx:
|
sctx:
|
ldw $20,$29,0
|
ldw $20,$29,0
|
ldw $19,$29,4
|
ldw $19,$29,4
|
ldw $18,$29,8
|
ldw $18,$29,8
|
ldw $17,$29,12
|
ldw $17,$29,12
|
ldw $16,$29,16
|
ldw $16,$29,16
|
ldw $31,$29,20
|
ldw $31,$29,20
|
add $29,$29,24
|
add $29,$29,24
|
jr $31
|
jr $31
|
|
|
