Add apps/sdct

A new app to stress test the SD card driver. Also, accompanying this
commit, changes solidifying the SD card driver so that stress tests
actually pass :)

apps/sdct/README.md

@@ -0,0 +1,4 @@
+# sdct - test SD Card
+
+This program stress-tests a SD card by repeatedly reading and writing to it and
+verify that data stays the same.

apps/sdct/glue.asm

@@ -0,0 +1,27 @@
+; sdct
+;
+; We want to test reading and writing random data in random sequences of
+; sectors. Collapse OS doesn't have a random number generator, so we'll simply
+; rely on initial SRAM value, which tend is random enough for our purpose.
+;
+; How it works is simple. From its designated RAMSTART, it calls PutC until it
+; reaches the end of RAM (0xffff). Then, it starts over and this time it reads
+; every byte and compares.
+;
+; If there's an error, prints out where.
+;
+; *** Requirements ***
+; sdcPutC
+; sdcGetC
+; printstr
+; printHexPair
+;
+; *** Includes ***
+
+#include "user.h"
+.org	USER_CODE
+.equ	SDCT_RAMSTART	USER_RAMSTART
+
+jp	sdctMain
+
+#include "sdct/main.asm"

apps/sdct/main.asm

@@ -0,0 +1,64 @@
+sdctMain:
+	ld	hl, .sWriting
+	call	printstr
+	ld	hl, 0
+	ld	de, SDCT_RAMSTART
+.wLoop:
+	ld	a, (de)
+	call	sdcPutC
+	jr	nz, .error
+	inc	hl
+	inc	de
+	; Stop looping if DE == 0
+	xor	a
+	cp	e
+	jr	nz, .wLoop
+	; print some kind of progress
+	call	printHexPair
+	cp	d
+	jr	nz, .wLoop
+	; Finished writing
+	ld	hl, .sReading
+	call	printstr
+	ld	hl, 0
+	ld	de, SDCT_RAMSTART
+.rLoop:
+	call	sdcGetC
+	jr	nz, .error
+	ex	de, hl
+	cp	(hl)
+	ex	de, hl
+	jr	nz, .notMatching
+	inc	hl
+	inc	de
+	; Stop looping if DE == 0
+	xor	a
+	cp	d
+	jr	nz, .rLoop
+	cp	e
+	jr	nz, .rLoop
+	; Finished checking
+	xor	a
+	ld	hl, .sOk
+	jp	printstr	; returns
+.notMatching:
+	; error position is in HL, let's preserve it
+	ex	de, hl
+	ld	hl, .sNotMatching
+	call	printstr
+	ex	de, hl
+	jp	printHexPair	; returns
+.error:
+	ld	hl, .sErr
+	jp	printstr	; returns
+
+.sWriting:
+	.db	"Writing", 0xd, 0xa, 0
+.sReading:
+	.db	"Reading", 0xd, 0xa, 0
+.sNotMatching:
+	.db	"Not matching at pos ", 0xd, 0xa, 0
+.sErr:
+	.db	"Error", 0xd, 0xa, 0
+.sOk:
+	.db	"OK", 0xd, 0xa, 0

kernel/sdc.asm

@@ -126,15 +126,12 @@ sdcWaitResp:
 ; This has no error condition and preserves A
 sdcWaitReady:
 	push	af
-	push	bc
-	ld	b, 20
+	; for now, we have no timeout for waiting. It means that broken SD
+	; cards can cause infinite loops.
 .loop:
 	call	sdcIdle
 	inc	a		; if 0xff, it's going to become zero
-	jr	z, .end		; zero? good, we're not busy any more
-	djnz	.loop
-.end:
-	pop	bc
+	jr	nz, .loop	; not zero? still busy. loop
 	pop	af
 	ret
 
@@ -169,6 +166,9 @@ sdcCmd:
 	call	sdcSendRecv
 	; send CRC
 	ld	a, c
+	; Most of the time, we don't care about C, but in all cases, we want
+	; the last bit to be high. It's the stop bit.
+	or	0x01
 	call	sdcSendRecv
 
 	; And now we just have to wait for a valid response...
@@ -275,20 +275,6 @@ sdcInitialize:
 	or	a		; cp 0
 	jr	nz, .error
 	; Success! out of idle mode!
-	; At this point, our buffers are innitialized. We could have some logic
-	; that determines whether a buffer is initialized in appropriate SDC
-	; routines and act appropriately, but why bother when we could, instead,
-	; just buffer the first two sectors of the card on initialization? This
-	; way, no need for special conditions.
-	; initialize variables
-	ld	hl, SDC_BUFSEC1
-	xor	a
-	ld	(SDC_BUFPTR), hl
-	call	sdcReadBlk		; read sector 0 in buf1
-	ld	hl, SDC_BUFSEC2
-	inc	a
-	ld	(SDC_BUFPTR), hl
-	call	sdcReadBlk		; read sector 1 in buf2
 	jr	.end
 
 .error:
@@ -322,6 +308,7 @@ sdcSetBlkSize:
 ; Returns 0 in A if success, non-zero if error.
 sdcReadBlk:
 	push	bc
+	push	de
 	push	hl
 
 	out	(SDC_PORT_CSLOW), a
@@ -371,6 +358,7 @@ sdcReadBlk:
 	call	sdcIdle
 	; success! wait until card is ready
 	call	sdcWaitReady
+	xor	a		; success
 	jr	.end
 .error:
 	; try to preserve error code
@@ -380,6 +368,7 @@ sdcReadBlk:
 .end:
 	out	(SDC_PORT_CSHIGH), a
 	pop	hl
+	pop	de
 	pop	bc
 	ret
 
@@ -451,6 +440,8 @@ sdcWriteBlk:
 
 	; Before returning, wait until card is ready
 	call	sdcWaitReady
+	xor	a
+	; A is already 0
 	jr	.end
 .error:
 	; try to preserve error code
@@ -538,7 +529,23 @@ sdcSync:
 sdcInitializeCmd:
 	.db	"sdci", 0, 0, 0
 	call	sdcInitialize
-	jp	sdcSetBlkSize		; returns
+	ret	nz
+	call	sdcSetBlkSize
+	ret	nz
+	; At this point, our buffers are unnitialized. We could have some logic
+	; that determines whether a buffer is initialized in appropriate SDC
+	; routines and act appropriately, but why bother when we could, instead,
+	; just buffer the first two sectors of the card on initialization? This
+	; way, no need for special conditions.
+	; initialize variables
+	ld	hl, SDC_BUFSEC1
+	xor	a
+	ld	(SDC_BUFPTR), hl
+	call	sdcReadBlk		; read sector 0 in buf1
+	ld	hl, SDC_BUFSEC2
+	inc	a
+	ld	(SDC_BUFPTR), hl
+	jp	sdcReadBlk		; read sector 1 in buf2, returns
 
 ; Flush the current SDC buffer if dirty
 sdcFlushCmd:
@@ -615,7 +622,10 @@ sdcPutC:
 	xor	a		; ensure Z
 	jr	.end
 .error:
+	; preserve error code
+	ex	af, af'
 	pop	af
+	ex	af, af'
 	call	unsetZ
 .end:
 	pop	hl

recipes/rc2014/zasm/Makefile

@@ -1,4 +1,4 @@
-CFSTARGETS = cfsin/zasm cfsin/user.h
+CFSTARGETS = cfsin/zasm cfsin/sdct cfsin/user.h
 BASE = ../../..
 TOOLS = $(BASE)/tools
 ZASM = $(TOOLS)/zasm.sh
@@ -21,5 +21,8 @@ sdcard.cfs: $(CFSTARGETS) $(CFSPACK)
 cfsin/zasm: $(ZASMBIN)
 	$(ZASM) $(KERNEL) $(APPS) user.h < $(APPS)/zasm/glue.asm > $@
 
+cfsin/sdct: $(ZASMBIN)
+	$(ZASM) $(APPS) user.h < $(APPS)/sdct/glue.asm > $@
+
 cfsin/user.h: user.h
 	cp $< $@

recipes/rc2014/zasm/glue.asm

@@ -41,6 +41,9 @@ jp	aciaInt
 	jp	_blkPutC
 	jp	_blkSeek
 	jp	_blkTell
+	jp	printHexPair
+	jp	sdcGetC
+	jp	sdcPutC
 
 #include "err.h"
 #include "core.asm"

recipes/rc2014/zasm/user.h

@@ -28,3 +28,6 @@
 .equ    _blkPutC       0x44
 .equ    _blkSeek       0x47
 .equ    _blkTell       0x4a
+.equ    printHexPair   0x4d
+.equ    sdcGetC        0x50
+.equ    sdcPutC        0x53