emul/hw/rc2014/classic.c

@@ -68,8 +68,8 @@ static void iowr_sdc_cslow(uint8_t val)
 
 int main(int argc, char *argv[])
 {
-    if (argc < 2) {
+    if (argc != 2) {
-        fprintf(stderr, "Usage: ./classic /path/to/rom [sdcard.img]\n");
+        fprintf(stderr, "Usage: ./classic /path/to/rom\n");
         return 1;
     }
     FILE *fp = fopen(argv[1], "r");
@@ -107,10 +107,6 @@ int main(int argc, char *argv[])
 
     acia_init(&acia);
     sdc_init(&sdc);
-    if (argc == 3) {
-        fprintf(stderr, "Setting up SD card image\n");
-        sdc.fp = fopen(argv[2], "r+");
-    }
     m->iord[ACIA_CTL_PORT] = iord_acia_ctl;
     m->iord[ACIA_DATA_PORT] = iord_acia_data;
     m->iowr[ACIA_CTL_PORT] = iowr_acia_ctl;
@@ -156,8 +152,5 @@ int main(int argc, char *argv[])
         tcsetattr(0, TCSADRAIN, &saved_term);
         emul_printdebug();
     }
-    if (sdc.fp) {
-        fclose(sdc.fp);
-    }
     return 0;
 }

emul/hw/rc2014/sdc.c

@@ -1,16 +1,6 @@
 #include <stdio.h>
 #include "sdc.h"
 
-// Add data to crc with polynomial 0x1021
-// https://stackoverflow.com/a/23726131
-static uint16_t crc16(uint16_t crc, uint8_t data)
-{
-    uint8_t x = crc >> 8 ^ data;
-    x ^= x>>4;
-    crc = (crc << 8) ^ ((uint16_t)(x << 12)) ^ ((uint16_t)(x <<5)) ^ ((uint16_t)x);
-    return crc;
-}
-
 void sdc_init(SDC *sdc)
 {
     sdc->selected = false;
@@ -18,9 +8,6 @@ void sdc_init(SDC *sdc)
     sdc->recvidx = 0;
     sdc->sendidx = -1;
     sdc->resp = 0xff;
-    sdc->fp = NULL;
-    sdc->cmd17bytes = -1;
-    sdc->cmd24bytes = -2;
 }
 
 void sdc_cslow(SDC *sdc)
@@ -51,61 +38,6 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
         }
         return;
     }
-    if (sdc->cmd17bytes >= 0) {
-        if (sdc->fp) {
-            sdc->resp = getc(sdc->fp);
-        }
-        sdc->crc16 = crc16(sdc->crc16, sdc->resp);
-        sdc->cmd17bytes++;
-        if (sdc->cmd17bytes == 512) {
-            sdc->sendbuf[3] = sdc->crc16 >> 8;
-            sdc->sendbuf[4] = sdc->crc16 & 0xff;
-            sdc->sendidx = 3;
-            sdc->cmd17bytes = -1;
-        }
-        return;
-    }
-    if (sdc->cmd24bytes == -1) {
-        if (val == 0xff) {
-            // it's ok to receive idle bytes before the data token.
-            return;
-        }
-        if (val == 0xfe) {
-            // data token, good
-            sdc->cmd24bytes = 0;
-        } else {
-            // something is wrong, cancel cmd24
-            sdc->cmd24bytes = -2;
-        }
-        return;
-    }
-    if (sdc->cmd24bytes >= 0) {
-        if (sdc->cmd24bytes < 512) {
-            if (sdc->fp) {
-                putc(val, sdc->fp);
-            }
-            sdc->crc16 = crc16(sdc->crc16, val);
-        } else if (sdc->cmd24bytes == 512) {
-            // CRC MSB
-            if (val == (sdc->crc16>>8)) {
-                fprintf(stderr, "Good CRC16 MSB\n");
-            } else {
-                fprintf(stderr, "Bad CRC16 MSB\n");
-            }
-        } else {
-            if (val == (sdc->crc16&0xff)) {
-                fprintf(stderr, "Good CRC16 LSB\n");
-            } else {
-                fprintf(stderr, "Bad CRC16 LSB\n");
-            }
-            // valid response for CMD24
-            sdc->sendbuf[4] = 0x05;
-            sdc->sendidx = 4;
-            sdc->cmd24bytes = -3;
-        }
-        sdc->cmd24bytes++;
-        return;
-    }
     if ((sdc->recvidx == 0) && ((val > 0x7f) || (val < 0x40))) {
         // not a command
         return;
@@ -119,9 +51,8 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
     val &= 0x3f;
     sdc->recvidx = 0;
     uint8_t *b = sdc->recvbuf;
+    fprintf(stderr, "cmd %02x %02x %02x %02x %02x\n", b[0], b[1], b[2], b[3], b[4]);
     uint8_t cmd = b[0] & 0x3f;
-    uint16_t arg1 = (b[1] << 8) | b[2];
-    uint16_t arg2 = (b[3] << 8) | b[4];
     if (sdc->initstat == 8) {
         // At this stage, we're expecting CMD0
         if (cmd == 0) {
@@ -133,7 +64,7 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
     }
     if (sdc->initstat == 9) {
         // At this stage, we're expecting CMD8 with 0x1aa arg2
-        if ((cmd == 8) && (arg2 == 0x01aa)) {
+        if ((cmd == 8) && (b[3] == 0x01) && (b[4] == 0xaa)) {
             sdc->initstat++;
             sdc->sendbuf[0] = 0x01;
             sdc->sendbuf[1] = 0;
@@ -159,7 +90,7 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
     }
     if (sdc->initstat == 11) {
         // At this stage, we're expecting CMD41
-        if ((cmd == 41) && (arg1 == 0x4000)) {
+        if ((cmd == 41) && (b[1] == 0x40) && (b[2] == 0x00)) {
             sdc->initstat++;
             sdc->sendbuf[4] = 0x00;
             sdc->sendidx = 4;
@@ -169,29 +100,6 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
         return;
     }
     // We have a fully initialized card.
-    if (cmd == 17) {
-        if (sdc->fp) {
-            fseek(sdc->fp, arg2*512, SEEK_SET);
-        }
-        sdc->sendbuf[3] = 0x00;
-        // data token
-        sdc->sendbuf[4] = 0xfe;
-        sdc->sendidx = 3;
-        sdc->cmd17bytes = 0;
-        sdc->crc16 = 0;
-        return;
-    }
-    if (cmd == 24) {
-        fprintf(stderr, "cmd24\n");
-        if (sdc->fp) {
-            fseek(sdc->fp, arg2*512, SEEK_SET);
-        }
-        sdc->sendbuf[4] = 0x00;
-        sdc->sendidx = 4;
-        sdc->cmd24bytes = -1;
-        sdc->crc16 = 0;
-        return;
-    }
     // Simulate success for any unknown command.
     sdc->sendbuf[4] = 0x00;
     sdc->sendidx = 4;

emul/hw/rc2014/sdc.h

@@ -19,15 +19,6 @@ typedef struct {
     // One byte response. When all other response buffers are empty, return
     // this.
     uint8_t resp;
-    // File used for contents read/write
-    FILE *fp;
-    // number of bytes read into the current CMD17. -1 means no CMD17 active.
-    int cmd17bytes;
-    // number of bytes received for the current CMD24. -2 means no CMD24 active.
-    // -1 means we're still waiting for the data token.
-    int cmd24bytes;
-    // running crc16 during read and write operations.
-    uint16_t crc16;
 } SDC;
 
 void sdc_init(SDC *sdc);