mach-sunxi: Add boot device detection for SUNIV/F1C100s

In contrast to other Allwinner SoCs the F1C100s BROM does not store a
boot source indicator in the eGON header in SRAM. This leaves the SPL
guessing where we were exactly booted from, and for instance trying
the SD card first, even though we booted from SPI flash.

By inspecting the BROM code and by experimentation, Samuel found that the
top of the BROM stack contains unique pointers for each of the boot
sources, which we can use as a boot source indicator.

This patch removes the existing board_boot_order bodge and replace it
with a proper boot source indication function.

The only caveat is that this only works in the SPL, as the SPL header
gets overwritten with the exception vectors, once U-Boot proper takes
over. Always return MMC0 as the boot source, when called from U-Boot
proper, as a placeholder for now, until we find another way.

Signed-off-by: Jesse Taube <[email protected]>
Suggested-by: Samuel Holland <[email protected]>
Reviewed-by: Andre Przywara <[email protected]>
Signed-off-by: Andre Przywara <[email protected]>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/include/asm/arch-sunxi/spl.h b/arch/arm/include/asm/arch-sunxi/spl.h
index 58cdf806d9a..b543d24e5a0 100644
--- a/arch/arm/include/asm/arch-sunxi/spl.h
+++ b/arch/arm/include/asm/arch-sunxi/spl.h
@@ -19,6 +19,15 @@
 #define SUNXI_BOOTED_FROM_MMC0_HIGH	0x10
 #define SUNXI_BOOTED_FROM_MMC2_HIGH	0x12
 
+/*
+ * Values taken from the F1C200s BootROM stack
+ * to determine where we booted from.
+ */
+#define SUNIV_BOOTED_FROM_MMC0	0xffff40f8
+#define SUNIV_BOOTED_FROM_NAND	0xffff4114
+#define SUNIV_BOOTED_FROM_SPI	0xffff4130
+#define SUNIV_BOOTED_FROM_MMC1	0xffff4150
+
 #define is_boot0_magic(addr)	(memcmp((void *)(addr), BOOT0_MAGIC, 8) == 0)
 
 uint32_t sunxi_get_boot_device(void);