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readres2 and readbytes assembly rewrite

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This commit is contained in:
Byron Lathi
2023-07-23 18:00:22 -07:00
parent 2ef463846f
commit 028a431189
2 changed files with 45 additions and 1 deletions
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4
sw/bootloader/devices/sd_card.c
View File

@@ -158,6 +158,7 @@ uint8_t SD_readRes1()
/******************************************************************************* /*******************************************************************************
Read R2 from SD card Read R2 from SD card
*******************************************************************************/ *******************************************************************************/
/*
void SD_readRes2(uint8_t *res) void SD_readRes2(uint8_t *res)
{ {
// read response 1 in R2 // read response 1 in R2
@@ -166,6 +167,7 @@ void SD_readRes2(uint8_t *res)
// read final byte of response // read final byte of response
res[1] = spi_exchange(0xFF); res[1] = spi_exchange(0xFF);
} }
*/
/******************************************************************************* /*******************************************************************************
Read R3 from SD card Read R3 from SD card
@@ -200,10 +202,12 @@ void SD_readRes7(uint8_t *res)
/******************************************************************************* /*******************************************************************************
Read specified number of bytes from SD card Read specified number of bytes from SD card
*******************************************************************************/ *******************************************************************************/
/*
void SD_readBytes(uint8_t *res, uint8_t n) void SD_readBytes(uint8_t *res, uint8_t n)
{ {
while(n--) *res++ = spi_exchange(0xFF); while(n--) *res++ = spi_exchange(0xFF);
} }
*/
/******************************************************************************* /*******************************************************************************
Command Idle State (CMD0) Command Idle State (CMD0)

42
sw/bootloader/devices/sd_card_asm.s
View File

@@ -1,7 +1,9 @@
.export _SD_command .export _SD_command
.export _SD_readRes1 .export _SD_readRes1
.export _SD_readRes2
.export _SD_readBytes
.importzp sp .importzp sp, ptr1
.autoimport on .autoimport on
@@ -50,5 +52,43 @@ tryread:
end: end:
rts rts
.endproc
; void SD_readRes2(uint8_t *res)
.proc _SD_readRes2: near
sta ptr1 ; store res in ptr1
stx ptr1 + 1
jsr _SD_readRes1 ; get first response 1
sta (ptr1)
lda #$ff
jsr _spi_exchange ; get final byte of response
ldy #$01
sta (ptr1),y
jsr incsp2
rts
.endproc
; void SD_readBytes(uint8_t *res, uint8_t n)
.proc _SD_readBytes: near
tax
jsr popptr1 ; store res in ptr1
read:
lda #$ff ; read data first
jsr _spi_exchange
sta (ptr1)
inc ptr1 ; then increment res
bne @L1
inc ptr1 + 1
@L1: dex ; then decrement x
bne read ; and if x is zero we are done
rts
.endproc .endproc