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https://github.com/brain-hackers/u-boot-brain
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![Marek Vasut](/assets/img/avatar_default.png)
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>
19 lines
355 B
ArmAsm
19 lines
355 B
ArmAsm
/*
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* Atmel SAMA5Dx boot parameter handling
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*
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* Copyright (c) 2016 Marek Vasut <marex@denx.de>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <asm-offsets.h>
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#include <config.h>
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#include <asm/system.h>
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#include <linux/linkage.h>
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ENTRY(save_boot_params)
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ldr r0, =bootrom_stash
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str r4, [r0, #0]
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b save_boot_params_ret
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ENDPROC(save_boot_params)
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