From 50b6db6a6b64b54f0020b431ed286a65baa7bbe0 Mon Sep 17 00:00:00 2001
From: rob-ng15 <58272847+rob-ng15@users.noreply.github.com>
Date: Tue, 17 Mar 2020 09:50:16 +0000
Subject: [PATCH] SPI hardware bitbanging from SD CARD

---
 litex/soc/software/bios/boot.c | 26 ++++++++++++++++++++++++++
 litex/soc/software/bios/boot.h |  4 ++++
 litex/soc/software/bios/main.c | 28 +++++-----------------------
 3 files changed, 35 insertions(+), 23 deletions(-)

diff --git a/litex/soc/software/bios/boot.c b/litex/soc/software/bios/boot.c
index f49d89e49..355f20a08 100644
--- a/litex/soc/software/bios/boot.c
+++ b/litex/soc/software/bios/boot.c
@@ -487,3 +487,29 @@ void romboot(void)
 	boot(0, 0, 0, ROM_BOOT_ADDRESS);
 }
 #endif
+
+// SPI HARDWARE BITBANG
+#ifdef CSR_SPI_BASE
+#include <spi.h>
+
+void spisdboot(void)
+{
+    printf("SD Card via SPI Initialising\n");
+    if(spi_sdcard_goidle() == 0) {
+        printf("SD Card Timeout\n");
+        return;
+    }
+    
+    if(spi_sdcard_readMBR() == 0) {
+        printf("SD Card MBR Timeout\n");
+        return;
+    }
+    
+    if(spi_sdcard_readFile("IMAGE","",MAIN_RAM_BASE+KERNEL_IMAGE_RAM_OFFSET)==0) return;
+    if(spi_sdcard_readFile("ROOTFS~1","CPI",MAIN_RAM_BASE+ROOTFS_IMAGE_RAM_OFFSET)==0) return;
+    if(spi_sdcard_readFile("RV32","DTB",MAIN_RAM_BASE+DEVICE_TREE_IMAGE_RAM_OFFSET)==0) return;
+    if(spi_sdcard_readFile("EMULATOR","BIN",EMULATOR_RAM_BASE)==0) return;
+    
+    boot(0,0,0,EMULATOR_RAM_BASE + EMULATOR_IMAGE_RAM_OFFSET);
+}
+#endif
diff --git a/litex/soc/software/bios/boot.h b/litex/soc/software/bios/boot.h
index 65dcf4574..fd1d06a2e 100644
--- a/litex/soc/software/bios/boot.h
+++ b/litex/soc/software/bios/boot.h
@@ -6,4 +6,8 @@ void netboot(void);
 void flashboot(void);
 void romboot(void);
 
+#ifdef CSR_SPI_BASE
+void spisdboot(void);
+#endif
+
 #endif /* __BOOT_H */
diff --git a/litex/soc/software/bios/main.c b/litex/soc/software/bios/main.c
index 83bff1e10..d1ca017e2 100644
--- a/litex/soc/software/bios/main.c
+++ b/litex/soc/software/bios/main.c
@@ -388,12 +388,8 @@ static void help(void)
 	puts("sdinit         - SDCard initialization");
 	puts("sdtest <loops> - SDCard test");
 #endif
-#ifdef USDDRPHY_DEBUG
-	puts("");
-	puts("sdram_cdly value                - Set SDRAM clk/cmd delay");
-	puts("sdram_cal                       - run SDRAM calibration");
-	puts("sdram_mpr                       - read SDRAM MPR");
-	puts("sdram_mrwr reg value            - write SDRAM mode registers");
+#ifdef CSR_SPI_BASE
+        puts("spisdboot   - boot from SDCard via SPI hardware bitbang");
 #endif
 }
 
@@ -486,24 +482,10 @@ static void do_command(char *c)
 	else if(strcmp(token, "sdinit") == 0) sdcard_init();
 	else if(strcmp(token, "sdtest") == 0) sdcard_test(atoi(get_token(&c)));
 #endif
-#ifdef USDDRPHY_DEBUG
-	else if(strcmp(token, "sdram_cdly") == 0)
-		ddrphy_cdly(atoi(get_token(&c)));
-	else if(strcmp(token, "sdram_cal") == 0)
-		sdrcal();
-	else if(strcmp(token, "sdram_mpr") == 0)
-		sdrmpr();
-	else if(strcmp(token, "sdram_mrwr") == 0) {
-		unsigned int reg;
-		unsigned int value;
-		reg = atoi(get_token(&c));
-		value = atoi(get_token(&c));
-		sdrsw();
-		printf("Writing 0x%04x to SDRAM mode register %d\n", value, reg);
-		sdrmrwr(reg, value);
-		sdrhw();
-	}
+#ifdef CSR_SPI_BASE
+        else if(strcmp(token, "spisdboot") == 0) spisdboot();
 #endif
+
 	else if(strcmp(token, "") != 0)
 		printf("Command not found\n");
 }