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Changes in INSTALL routine from emd/c128-vdc.s.

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tmp1 was used at two places resulting in the bug that VDC_CSET was set to garbage on 16k VDC.
pagecount and curpage were not reset on INSTALL resulting in non-reentrant code on static linkage of emd driver.
This commit is contained in:
mc78 2019-11-29 11:20:58 +01:00 committed by greg-king5
parent 5109c0b68f
commit 2a42139674
1 changed files with 29 additions and 19 deletions
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48
libsrc/c128/emd/c128-vdc.s
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@ -52,13 +52,11 @@ VDC_DATA = 31
; ------------------------------------------------------------------------
; Data.
.data
pagecount: .word 64 ; $0000-$3fff as 16k default
curpage: .word $ffff ; currently mapped-in page (invalid)
.bss
pagecount: .res 1 ; $0000-$3fff as 16k default
curpage: .res 2 ; currently mapped-in page (invalid)
vdc_cset_save: .res 1
window: .res 256 ; memory window
.code
@ -71,11 +69,15 @@ window: .res 256 ; memory window
;
INSTALL:
; reset mapped-in page to invalid
lda #$ff
sta curpage
sta curpage+1
; do test for VDC presence here???
ldx #VDC_CSET ; determine size of RAM...
jsr vdcgetreg
sta tmp1
sta vdc_cset_save
ora #%00010000
jsr vdcputreg ; turn on 64k
@ -94,35 +96,39 @@ INSTALL:
lda tmp2
jsr vdcputbyte ; restore original value of test byte
ldx #0 ; prepare x with hi of default pagecount
lda ptr1 ; do bytes match?
cmp ptr1+1
bne @have64k
lda ptr2
cmp ptr2+1
bne @have64k
ldx #VDC_CSET
lda tmp1
jsr vdcputreg ; restore 16/64k flag
jmp @endok ; and leave default values for 16k
@have64k:
lda #<256
ldx #>256
lda #64 ; assumes x = 0, here -> p.c = 64
bne @setpagecnt
@have64k:
txa ; assumes x = 0, here
inx ; so that a/x becomes 0/1 -> p.c. = 256
@setpagecnt:
sta pagecount
stx pagecount+1
@endok:
ldx #VDC_CSET ; restore 16/64k flag
lda vdc_cset_save
jsr vdcputreg
lda #<EM_ERR_OK
ldx #>EM_ERR_OK
rts
test64k:
sta tmp1
sta tmp3
sty ptr3
lda #0
sta ptr3+1
jsr settestadr1
lda tmp1
lda tmp3
jsr vdcputbyte ; write $55
jsr settestadr1
jsr vdcgetbyte ; read here
@ -199,6 +205,8 @@ transferin:
lda VDC_DATA_REG ; get 2 bytes at a time to speed-up
sta (ptr2),y ; (in fact up to 8 bytes could be fetched with special VDC config)
iny
@L1: bit VDC_ADDR_REG ; XXX: Test waiting for register 31
bpl @L1
lda VDC_DATA_REG
sta (ptr2),y
iny
@ -334,6 +342,8 @@ vdcsetsrcaddr:
dex
tya
stx VDC_ADDR_REG
@L1: bit VDC_ADDR_REG ; XXX: Test waiting for register 18
bpl @L1
sta VDC_DATA_REG
rts