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Add software support for sd response codes

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Polls the sd controller until the read flag is set, at which point it
reads 32 bits of data from the controller.

long response codes (such as CID) are not supported in hw or sw.
This commit is contained in:
Byron Lathi
2022-04-10 23:18:26 -05:00
parent f5f1d7ccc6
commit 9eaa6c49f9
3 changed files with 68 additions and 18 deletions
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25
sw/sd_card.s
View File

@@ -1,8 +1,9 @@
.include "io.inc65"
.importzp sp, sreg
.importzp sp, sreg, ptr1
.export _sd_card_command
.export _sd_card_resp
.autoimport on
@@ -25,3 +26,25 @@ _sd_card_command:
pla
sta SD_CMD
rts
; void sd_card_resp(uint32_t* resp);
_sd_card_resp:
phy
sta ptr1 ; store pointer
stx ptr1+1
@1: lda SD_CMD ; wait for status flag
beq @1
lda SD_ARG
ldy #$0
sta (ptr1),y
lda SD_ARG+1
iny
sta (ptr1),y
lda SD_ARG+2
iny
sta (ptr1),y
lda SD_ARG+3
iny
sta (ptr1),y
ply
rts