X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=arch%2Farm%2Fcpu%2Farmv7%2Fsunxi%2Fboard.c;h=c02c0150960c2be2ee2324c680d86d258f09b4f2;hb=ebd468b2d26660ff7811e37cc64fa2369d4b5fff;hp=f4a580a24218d1daa7aabd1dcdcffc9b9b2e25a1;hpb=1cd20006989532c0a688870a43727ace58997785;p=oweals%2Fu-boot.git

diff --git a/arch/arm/cpu/armv7/sunxi/board.c b/arch/arm/cpu/armv7/sunxi/board.c
index f4a580a242..c02c015096 100644
--- a/arch/arm/cpu/armv7/sunxi/board.c
+++ b/arch/arm/cpu/armv7/sunxi/board.c
@@ -27,25 +27,16 @@
 
 #include <linux/compiler.h>
 
-#ifdef CONFIG_SPL_BUILD
-/* Pointer to the global data structure for SPL */
-DECLARE_GLOBAL_DATA_PTR;
-
-/* The sunxi internal brom will try to loader external bootloader
- * from mmc0, nand flash, mmc2.
- * Unfortunately we can't check how SPL was loaded so assume
- * it's always the first SD/MMC controller
- */
-u32 spl_boot_device(void)
-{
-	return BOOT_DEVICE_MMC1;
-}
+struct fel_stash {
+	uint32_t sp;
+	uint32_t lr;
+	uint32_t cpsr;
+	uint32_t sctlr;
+	uint32_t vbar;
+	uint32_t cr;
+};
 
-/* No confirmation data available in SPL yet. Hardcode bootmode */
-u32 spl_boot_mode(void)
-{
-	return MMCSD_MODE_RAW;
-}
+struct fel_stash fel_stash __attribute__((section(".data")));
 
 static int gpio_init(void)
 {
@@ -85,7 +76,13 @@ static int gpio_init(void)
 	return 0;
 }
 
-void board_init_f(ulong dummy)
+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
 	/* Magic (undocmented) value taken from boot0, without this DRAM
@@ -105,7 +102,54 @@ void board_init_f(ulong dummy)
 	timer_init();
 	gpio_init();
 	i2c_init_board();
+}
 
+#ifdef CONFIG_SPL_BUILD
+/* The sunxi internal brom will try to loader external bootloader
+ * from mmc0, nand flash, mmc2.
+ * Unfortunately we can't check how SPL was loaded so assume
+ * it's always the first SD/MMC controller
+ */
+u32 spl_boot_device(void)
+{
+#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 */
+u32 spl_boot_mode(void)
+{
+	return MMCSD_MODE_RAW;
+}
+
+void board_init_f(ulong dummy)
+{
 	preloader_console_init();
 
 #ifdef CONFIG_SPL_I2C_SUPPORT