On 05/03/2016 10:52 AM, Andreas Bießmann wrote:
On Fri, Apr 22, 2016 at 09:56:21PM +0200, Marek Vasut wrote:
Implement support for saving ARM register R4 early during boot using save_boot_params . Implement support for decoding the stored register R4 value in spl_boot_device() to obtain boot device from which the SoC booted. This way, the SPL will always load U-Boot from the same device from which the SPL itself booted instead of using hard-coded boot device.
This functionality is useful for example when booting sama5d2-xplained from SD card, where by default the SPL would try loading the U-Boot from eMMC and fail. This is because eMMC is on SDHCI0 (BOOT_DEVICE_MMC1), while SD slot is on SDHCI1 (BOOT_DEVICE_MMC2) and the SPL was hard-wired to always boot from BOOT_DEVICE_MMC1.
Signed-off-by: Marek Vasut marex@denx.de Cc: Andreas Bießmann andreas.devel@googlemail.com Cc: Wenyou Yang wenyou.yang@atmel.com
Reviewed-by: Andreas Bießmann andreas@biessmann.org
I will eventually extend this to SAMA5Dx as this is quite helpful on upcoming board.
arch/arm/mach-at91/Makefile | 2 +- arch/arm/mach-at91/bootparams_atmel.S | 18 ++++++++++++++++ arch/arm/mach-at91/include/mach/sama5d2.h | 12 +++++++++++ arch/arm/mach-at91/spl.c | 36 +++++++++++++++++++++++++++++++ 4 files changed, 67 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mach-at91/bootparams_atmel.S