On 04/18/2016 09:54 AM, Andreas Bießmann wrote:
Hi Marek,
On 2016-04-18 17:30, Marek Vasut wrote:
Hi!
I've been playing around with latest mainline u-boot on sama5d2 xplained ultra. I noticed that if I want to boot the board from SD card (SDHCI1), the board will indeed load the SPL from it, but SPL will try to load u-boot.img from eMMC (SDHCI0) and fail, as my eMMC is blank. This is a result of hard-coding boot device to BOOT_DEVICE_MMC1 in arch/arm/mach-at91/spl.c spl_boot_device() I think.
Is there any way to discern from which SDHCI the board booted to continue loading u-boot.img from the correct one ? This would let us implement board_boot_order() and boot from correct SDHCI.
AFIAK it is not possible to detect the boot medium in a running device. At least was this the case when I checked it the last time (for sama5d3).
For the TI am5728 (ARM V7), there is a register, CTRL_CORE_BOOTSTRAP (0x4A0026C4) which contains the boot device selection at last power cycle. I'm new to ARM so I don't know how likely it is that the Atmel part has a similar register. Good luck.