bios/sdram: add BIOS command for reading SPD

diff --git a/litex/soc/software/bios/cmds/cmd_litedram.c b/litex/soc/software/bios/cmds/cmd_litedram.c
index 0b9ea2280fe37175608e9900dc2ae901086c256e..1fcce272a344b700b7ba52a56c5df4cd30cd8862 100644 (file)
--- a/litex/soc/software/bios/cmds/cmd_litedram.c
+++ b/litex/soc/software/bios/cmds/cmd_litedram.c
@@ -221,3 +221,56 @@ define_command(sdrlevel, sdrlevel, "Perform read/write leveling", LITEDRAM_CMDS)
 #ifdef CSR_SDRAM_BASE
 define_command(memtest, memtest, "Run a memory test", LITEDRAM_CMDS);
 #endif
+
+
+/**
+ * Command "spdread"
+ *
+ * Read contents of SPD EEPROM memory.
+ * SPD address is defined by the pins A0, A1, A2.
+ *
+ */
+#ifdef CSR_I2C_BASE
+static void spdread_handler(int nb_params, char **params)
+{
+       unsigned char buf[256];
+       unsigned int spdaddr;
+       int length = sizeof(buf);
+       char *c;
+
+       if (nb_params < 1) {
+               printf("spdread <spdaddr> [<length>]");
+               return;
+       }
+
+       spdaddr = strtoul(params[0], &c, 0);
+       if (*c != 0) {
+               printf("Incorrect address");
+               return;
+       }
+       if (spdaddr > 0b111) {
+               printf("SPD EEPROM max address is 0b111 (defined by A0, A1, A2 pins)");
+               return;
+       }
+
+       if (nb_params > 1) {
+               length = strtoul(params[1], &c, 0);
+               if (*c != 0) {
+                       printf("Incorrect address");
+                       return;
+               }
+               if (length > sizeof(buf)) {
+                       printf("Max length is %d", sizeof(buf));
+                       return;
+               }
+       }
+
+       if (!spdread(spdaddr, 0, buf, length)) {
+               printf("Error when reading SPD EEPROM");
+               return;
+       }
+
+       dump_bytes((unsigned int *) buf, length, 0);
+}
+define_command(spdread, spdread_handler, "Read SPD EEPROM", LITEDRAM_CMDS);
+#endif