software/liblitesdcard/sdcard: boot with FatFs working (hacky).

Tested with Linux-on-LiteX-Vexriscv on Trellisboard with 10MHz clock.

diff --git a/litex/soc/software/liblitesdcard/sdcard.c b/litex/soc/software/liblitesdcard/sdcard.c
index abf8e7dbd74ac03ef4736a3363d46d2990747c23..2610e1781ade15d2e402747bf27ab7d5188d9c90 100644 (file)
--- a/litex/soc/software/liblitesdcard/sdcard.c
+++ b/litex/soc/software/liblitesdcard/sdcard.c
@@ -16,7 +16,7 @@
 #include "fat/diskio.h"
 #include "sdcard.h"
 
-#define SDCARD_DEBUG
+//#define SDCARD_DEBUG
 #define SDCARD_WAIT_WORKAROUND
 
 #ifdef CSR_SDCORE_BASE
@@ -153,12 +153,22 @@ void sdclk_set_clk(unsigned int freq) {
 
 /* command utils */
 
+static void busy_wait_us(unsigned int us)
+{
+    timer0_en_write(0);
+    timer0_reload_write(0);
+    timer0_load_write(CONFIG_CLOCK_FREQUENCY/1000000*us);
+    timer0_en_write(1);
+    timer0_update_value_write(1);
+    while(timer0_value_read()) timer0_update_value_write(1);
+}
+
 int sdcard_wait_cmd_done(void) {
        unsigned int cmdevt;
        while (1) {
                cmdevt = sdcore_cmdevt_read();
 #ifdef SDCARD_WAIT_WORKAROUND
-               busy_wait(5); /* FIXME */
+               busy_wait_us(40); /* FIXME */
 #endif
 #ifdef SDCARD_DEBUG
                printf("cmdevt: %08x\n", cmdevt);
@@ -186,7 +196,7 @@ int sdcard_wait_data_done(void) {
        while (1) {
                dataevt = sdcore_dataevt_read();
 #ifdef SDCARD_WAIT_WORKAROUND
-               busy_wait(5); /* FIXME */
+               busy_wait_us(1); /* FIXME */
 #endif
 #ifdef SDCARD_DEBUG
                printf("dataevt: %08x\n", dataevt);
@@ -672,6 +682,7 @@ void sdcard_read(unsigned int addr, char silent)
        sdcard_set_block_count(1);
        sdcard_sddatareader_start();
        sdcard_read_single_block(addr);
+       flush_cpu_dcache(); /* FIXME */
        sdcard_sddatareader_wait();
 
        if (silent == 0)
@@ -734,11 +745,13 @@ DSTATUS disk_initialize(uint8_t drv) {
 }
 
 DRESULT disk_read(uint8_t drv, uint8_t *buf, uint32_t sector, uint32_t count) {
+       uint32_t i = 0;
        while (count) {
-               sdcard_read(sector, 1);
+               sdcard_read(sector + i, 1);
                memcpy((char*) buf, (char*) sdread_buf, SD_BLOCK_SIZE);
                buf += SD_BLOCK_SIZE;
                count--;
+               i++;
        }
        return RES_OK;
 }