Copy sdc driver to blkfs

blk/001

@@ -4,7 +4,7 @@ MASTER INDEX
  70 Implementation notes      100 Block editor
 200 Z80 assembler             260 Cross compilation
 280 Z80 boot code             350 ACIA driver
-
+370 SD Card driver
 
 
 

blk/370

@@ -0,0 +1,4 @@
+SD Card driver
+
+Load the z80 part with "372 LOAD", the Forth part with
+"374 LOAD".

blk/372

@@ -1,7 +1,6 @@
-( n -- n )
 ( Initiate SPI exchange with the SD card. n is the data to
   send. )
-CODE _sdcSR
+CODE _sdcSR  ( n -- n )
     HL POPqq,
     chkPS,
     A L LDrr,
@@ -12,10 +11,4 @@ CODE _sdcSR
     HL PUSHqq,
 ;CODE
 
-CODE _sdcSel
+373 LOAD
-    SDC_CSLOW OUTnA,
-;CODE
-
-CODE _sdcDesel
-    SDC_CSHIGH OUTnA,
-;CODE

blk/373

@@ -0,0 +1,9 @@
+CODE _sdcSel
+    SDC_CSLOW OUTnA,
+;CODE
+
+CODE _sdcDesel
+    SDC_CSHIGH OUTnA,
+;CODE
+
+

blk/374

@@ -0,0 +1,16 @@
+( -- n )
+: _idle 0xff _sdcSR ;
+
+( -- n )
+( _sdcSR 0xff until the response is something else than 0xff
+  for a maximum of 20 times. Returns 0xff if no response. )
+: _wait
+    0  ( cnt )
+    BEGIN
+        _idle
+        DUP 0xff = IF DROP ELSE SWAP DROP EXIT THEN
+        1+
+    DUP 20 = UNTIL
+    DROP 0xff
+;
+375 386 LOADR

blk/375

@@ -0,0 +1,10 @@
+( -- )
+( The opposite of sdcWaitResp: we wait until response is 0xff.
+  After a successful read or write operation, the card will be
+  busy for a while. We need to give it time before interacting
+  with it again. Technically, we could continue processing on
+  our side while the card it busy, and maybe we will one day,
+  but at the moment, I'm having random write errors if I don't
+  do this right after a write, so I prefer to stay cautious
+  for now. )
+: _ready BEGIN _idle 0xff = UNTIL ;

blk/376

@@ -0,0 +1,16 @@
+( c n -- c )
+( Computes n into crc c with polynomial 0x09
+  Note that the result is "left aligned", that is, that 8th
+  bit to the "right" is insignificant (will be stop bit). )
+: _crc7
+    XOR           ( c )
+    8 0 DO
+        2 *       ( <<1 )
+        DUP 255 > IF
+            ( MSB was set, apply polynomial )
+            0xff AND
+            0x12 XOR  ( 0x09 << 1, we apply CRC on high bits )
+        THEN
+    LOOP
+;
+

blk/377

@@ -0,0 +1,16 @@
+( c n -- c )
+( Computes n into crc c with polynomial 0x1021 )
+: _crc16
+    SWAP DUP 256 /    ( n c c>>8 )
+    ROT XOR           ( c x )
+    DUP 16 / XOR      ( c x^x>>4 )
+    SWAP 256 *        ( x c<<8 )
+    OVER 4096 * XOR   ( x c^x<<12 )
+    OVER 32 * XOR     ( x c^x<<5 )
+    XOR               ( c )
+;
+
+( send-and-crc7 )
+( n c -- c )
+: _s+crc SWAP DUP _sdcSR DROP _crc7 ;
+

blk/378

@@ -0,0 +1,16 @@
+( cmd arg1 arg2 -- resp )
+( Sends a command to the SD card, along with arguments and
+  specified CRC fields. (CRC is only needed in initial commands
+  though). This does *not* handle CS. You have to
+  select/deselect the card outside this routine. )
+: _cmd
+    _wait DROP ROT    ( a1 a2 cmd )
+    0 _s+crc          ( a1 a2 crc )
+    ROT 256 /MOD ROT  ( a2 h l crc )
+    _s+crc _s+crc     ( a2 crc )
+    SWAP 256 /MOD ROT ( h l crc )
+    _s+crc _s+crc     ( crc )
+    0x01 OR           ( ensure stop bit )
+    _sdcSR DROP       ( send CRC )
+    _wait  ( wait for a valid response... )
+;

blk/379

@@ -0,0 +1,16 @@
+( cmd arg1 arg2 -- r )
+( Send a command that expects a R1 response, handling CS. )
+: SDCMDR1 _sdcSel _cmd _sdcDesel ;
+
+( cmd arg1 arg2 -- r arg1 arg2 )
+( Send a command that expects a R7 response, handling CS. A R7
+  is a R1 followed by 4 bytes. arg1 contains bytes 0:1, arg2
+  has 2:3 )
+: SDCMDR7
+    _sdcSel
+    _cmd                 ( r )
+    _idle 256 * _idle +  ( r arg1 )
+    _idle 256 * _idle +  ( r arg1 arg2 )
+    _sdcDesel
+;
+

blk/380

@@ -0,0 +1,16 @@
+: _err _sdcDesel ABORT" SDerr" ;
+
+( Initialize a SD card. This should be called at least 1ms
+  after the powering up of the card. )
+: SDC$
+( Wake the SD card up. After power up, a SD card has to receive
+  at least 74 dummy clocks with CS and DI high. We send 80. )
+    10 0 DO _idle DROP LOOP
+    ( call cmd0 and expect a 0x01 response (card idle)
+	  this should be called multiple times. we're actually
+      expected to. let's call this for a maximum of 10 times. )
+    0 ( dummy )
+    10 0 DO  ( r )
+        DROP 0x40 0 0 SDCMDR1  ( CMD0 )
+        DUP 0x01 = IF LEAVE THEN
+    LOOP 0x01 = NOT IF _err THEN                      ( cont. )

blk/381

@@ -0,0 +1,10 @@
+( Then comes the CMD8. We send it with a 0x01aa argument and
+  expect a 0x01aa argument back, along with a 0x01 R1
+  response. )
+    0x48 0 0x1aa  ( CMD8 )
+    SDCMDR7                     ( r arg1 arg2 )
+    0x1aa = NOT IF _err THEN    ( arg2 check )
+    0 = NOT IF _err THEN        ( arg1 check )
+    0x01 = NOT IF _err THEN     ( r check )
+
+                                                      ( cont. )

blk/382

@@ -0,0 +1,13 @@
+( Now we need to repeatedly run CMD55+CMD41 (0x40000000)
+  until the card goes out of idle mode, that is, when it stops
+  sending us 0x01 response and send us 0x00 instead. Any other
+  response means that initialization failed. )
+    BEGIN
+        0x77 0 0 SDCMDR1  ( CMD55 )
+        0x01 = NOT IF _err THEN
+        0x69 0x4000 0x0000 SDCMDR1  ( CMD41 )
+        DUP 0x01 > IF _err THEN
+    NOT UNTIL
+    ( Out of idle mode! Success! )
+;
+

blk/383

@@ -0,0 +1,15 @@
+: _sdc@  ( dstaddr blkno -- )
+    _sdcSel 0x51 ( CMD17 ) 0 ROT ( a cmd 0 blkno ) _cmd
+    IF _err THEN
+    _wait 0xfe = NOT IF _err THEN
+    0 SWAP               ( crc a )
+    512 0 DO             ( crc a )
+        DUP _idle        ( crc a a n )
+        DUP ROT C!       ( crc a n )
+        ROT SWAP _crc16  ( a crc )
+        SWAP 1+          ( crc a+1 )
+    LOOP
+    DROP                 ( crc1 )
+    _idle 256 * _idle +  ( crc2 )
+    _wait DROP _sdcDesel
+    = NOT IF _err THEN ;

blk/384

@@ -0,0 +1,7 @@
+: SDC@
+    2 * DUP BLK( SWAP    ( b a b )
+    _sdc@
+    1+ BLK( 512 + SWAP
+    _sdc@
+;
+

blk/385

@@ -0,0 +1,16 @@
+: _sdc!  ( srcaddr blkno -- )
+    _sdcSel 0x58 ( CMD24 ) 0 ROT ( a cmd 0 blkno ) _cmd
+    IF _err THEN
+    _idle DROP 0xfe _sdcSR DROP
+    0 SWAP           ( crc a )
+    512 0 DO         ( crc a )
+        C@+          ( crc a+1 n )
+        ROT OVER     ( a n crc n )
+        _crc16       ( a n crc )
+        SWAP         ( a crc n )
+        _sdcSR DROP  ( a crc )
+        SWAP         ( crc a )
+    LOOP
+    DROP ( crc ) 256 /MOD ( lsb msb )
+    _sdcSR DROP _sdcSR DROP
+    _wait DROP _sdcDesel ;

blk/386

@@ -0,0 +1,7 @@
+: SDC!
+    2 * DUP BLK( SWAP    ( b a b )
+    _sdc!
+    1+ BLK( 512 + SWAP
+    _sdc!
+;
+

recipes/rc2014/Makefile

@@ -7,7 +7,6 @@ EMUL = $(BASEDIR)/emul/hw/rc2014/classic
 BOOTSRCS = conf.fs \
 	$(EDIR)/xcomp.fs \
 	drvz80.fs \
-	$(BASEDIR)/drv/sdc.z80 \
 	$(FDIR)/icore.fs \
 	$(EDIR)/stop.fs
 

recipes/rc2014/drvz80.fs

@@ -1 +1,2 @@
 352 LOAD    ( acia.z80 )
+372 LOAD    ( sdc.z80 )