sf: Add spi_boot() to allow booting from SPI flash in an SPL

[karo-tx-uboot.git] / drivers / mtd / spi / spi_spl_load.c

diff --git a/drivers/mtd/spi/spi_spl_load.c b/drivers/mtd/spi/spi_spl_load.c
new file mode 100644 (file)
index 0000000..1aa30ac
--- /dev/null
+++ b/drivers/mtd/spi/spi_spl_load.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2011 OMICRON electronics GmbH
+ *
+ * based on drivers/mtd/nand/nand_spl_load.c
+ *
+ * Copyright (C) 2011
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <spi_flash.h>
+
+/*
+ * The main entry for SPI booting. It's necessary that SDRAM is already
+ * configured and available since this code loads the main U-Boot image
+ * from SPI into SDRAM and starts it from there.
+ */
+void spi_boot(void)
+{
+       struct spi_flash *flash;
+       void (*uboot)(void) __noreturn;
+
+       /*
+        * Load U-Boot image from SPI flash into RAM
+        */
+
+       flash = spi_flash_probe(CONFIG_SPL_SPI_BUS, CONFIG_SPL_SPI_CS,
+                               CONFIG_SF_DEFAULT_SPEED, SPI_MODE_3);
+       if (!flash) {
+               puts("failed.\n");
+               hang();
+       }
+
+       spi_flash_read(flash, CONFIG_SYS_SPI_U_BOOT_OFFS,
+                      CONFIG_SYS_SPI_U_BOOT_SIZE,
+                      (void *) CONFIG_SYS_TEXT_BASE);
+
+       /*
+        * Jump to U-Boot image
+        */
+       uboot = (void *) CONFIG_SYS_TEXT_BASE;
+       (*uboot)();
+}