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emul/hw/rc2014: implement blkread in sdc

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I now get to "fls" in recipes/rc2014/sdcard!
This commit is contained in:
Virgil Dupras 2020-04-17 19:10:22 -04:00
parent ae470397d7
commit 7544b3834b
3 changed files with 57 additions and 5 deletions
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11
emul/hw/rc2014/classic.c
View File

@ -68,8 +68,8 @@ static void iowr_sdc_cslow(uint8_t val)
int main(int argc, char *argv[])
{
if (argc != 2) {
fprintf(stderr, "Usage: ./classic /path/to/rom\n");
if (argc < 2) {
fprintf(stderr, "Usage: ./classic /path/to/rom [sdcard.img]\n");
return 1;
}
FILE *fp = fopen(argv[1], "r");
@ -107,6 +107,10 @@ 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;
@ -152,5 +156,8 @@ int main(int argc, char *argv[])
tcsetattr(0, TCSADRAIN, &saved_term);
emul_printdebug();
}
if (sdc.fp) {
fclose(sdc.fp);
}
return 0;
}

45
emul/hw/rc2014/sdc.c
View File

@ -1,6 +1,16 @@
#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;
@ -8,6 +18,8 @@ void sdc_init(SDC *sdc)
sdc->recvidx = 0;
sdc->sendidx = -1;
sdc->resp = 0xff;
sdc->fp = NULL;
sdc->cmd17bytes = -1;
}
void sdc_cslow(SDC *sdc)
@ -38,6 +50,20 @@ 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->recvidx == 0) && ((val > 0x7f) || (val < 0x40))) {
// not a command
return;
@ -51,8 +77,9 @@ 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) {
@ -64,7 +91,7 @@ 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) && (b[3] == 0x01) && (b[4] == 0xaa)) {
if ((cmd == 8) && (arg2 == 0x01aa)) {
sdc->initstat++;
sdc->sendbuf[0] = 0x01;
sdc->sendbuf[1] = 0;
@ -90,7 +117,7 @@ void sdc_spi_wr(SDC *sdc, uint8_t val)
}
if (sdc->initstat == 11) {
// At this stage, we're expecting CMD41
if ((cmd == 41) && (b[1] == 0x40) && (b[2] == 0x00)) {
if ((cmd == 41) && (arg1 == 0x4000)) {
sdc->initstat++;
sdc->sendbuf[4] = 0x00;
sdc->sendidx = 4;
@ -100,6 +127,18 @@ 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;
}
// Simulate success for any unknown command.
sdc->sendbuf[4] = 0x00;
sdc->sendidx = 4;

6
emul/hw/rc2014/sdc.h
View File

@ -19,6 +19,12 @@ 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;
// running crc16 during read and write operations.
uint16_t crc16;
} SDC;
void sdc_init(SDC *sdc);