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-rw-r--r--arch/arm/cpu/armv7/sunxi/board.c46
1 files changed, 45 insertions, 1 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/board.c b/arch/arm/cpu/armv7/sunxi/board.c
index 6e28bcd040..c02c015096 100644
--- a/arch/arm/cpu/armv7/sunxi/board.c
+++ b/arch/arm/cpu/armv7/sunxi/board.c
@@ -27,6 +27,17 @@
#include <linux/compiler.h>
+struct fel_stash {
+ uint32_t sp;
+ uint32_t lr;
+ uint32_t cpsr;
+ uint32_t sctlr;
+ uint32_t vbar;
+ uint32_t cr;
+};
+
+struct fel_stash fel_stash __attribute__((section(".data")));
+
static int gpio_init(void)
{
#if CONFIG_CONS_INDEX == 1 && defined(CONFIG_UART0_PORT_F)
@@ -65,6 +76,12 @@ static int gpio_init(void)
return 0;
}
+void spl_board_load_image(void)
+{
+ debug("Returning to FEL sp=%x, lr=%x\n", fel_stash.sp, fel_stash.lr);
+ return_to_fel(fel_stash.sp, fel_stash.lr);
+}
+
void s_init(void)
{
#if defined CONFIG_MACH_SUN6I || defined CONFIG_MACH_SUN8I
@@ -95,7 +112,34 @@ void s_init(void)
*/
u32 spl_boot_device(void)
{
- return BOOT_DEVICE_MMC1;
+#ifdef CONFIG_SPL_FEL
+ /*
+ * This is the legacy compile time configuration for a special FEL
+ * enabled build. It has many restrictions and can only boot over USB.
+ */
+ return BOOT_DEVICE_BOARD;
+#else
+ /*
+ * When booting from the SD card, the "eGON.BT0" signature is expected
+ * to be found in memory at the address 0x0004 (see the "mksunxiboot"
+ * tool, which generates this header).
+ *
+ * When booting in the FEL mode over USB, this signature is patched in
+ * memory and replaced with something else by the 'fel' tool. This other
+ * signature is selected in such a way, that it can't be present in a
+ * valid bootable SD card image (because the BROM would refuse to
+ * execute the SPL in this case).
+ *
+ * This branch is just making a decision at runtime whether to load
+ * the main u-boot binary from the SD card (if the "eGON.BT0" signature
+ * is found) or return to the FEL code in the BROM to wait and receive
+ * the main u-boot binary over USB.
+ */
+ if (readl(4) == 0x4E4F4765 && readl(8) == 0x3054422E) /* eGON.BT0 */
+ return BOOT_DEVICE_MMC1;
+ else
+ return BOOT_DEVICE_BOARD;
+#endif
}
/* No confirmation data available in SPL yet. Hardcode bootmode */
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