omap-common: SYS_BOOT-based fallback boot device selection for peripheral boot
OMAP devices might boot from peripheral devices, such as UART or USB.
When that happens, the U-Boot SPL tries to boot the next stage (complete U-Boot)
from that peripheral device, but in most cases, this is not a valid boot device.
This introduces a fallback option that reads the SYS_BOOT pins, that are used by
the bootrom to determine which device to boot from. It is intended for the
SYS_BOOT value to be interpreted in the memory-preferred scheme, so that the
U-Boot SPL can load the next stage from a valid location.
Practically, this options allows loading the U-Boot SPL through USB and have it
load the next stage according to the memory device selected by SYS_BOOT instead
of stalling.
Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
diff --git a/arch/arm/include/asm/omap_common.h b/arch/arm/include/asm/omap_common.h
index 084ea68..056affc 100644
--- a/arch/arm/include/asm/omap_common.h
+++ b/arch/arm/include/asm/omap_common.h
@@ -697,4 +697,8 @@
#define CH_FLAGS_CHFLASH (1 << 2)
#define CH_FLAGS_CHMMCSD (1 << 3)
+#ifndef __ASSEMBLY__
+u32 omap_sys_boot_device(void);
+#endif
+
#endif /* _OMAP_COMMON_H_ */