mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-07-09 20:56:16 +09:00
840fe95c3b
So that the CONFIG_SPL_FEL option is not needed anymore. And the regular SPL binary, generated by the default u-boot build, is now also bootable over USB in the FEL mode. The SPL still can boot from the SD card too. A bunch of system registers need to be saved/restored in order to ensure that the IRQ handler still works in the BROM FEL code after getting control back from the SPL. This is done in the sunxi code instead of abusing ifdefs in 'start.S'. The decision whether to load the main u-boot binary from the SD card or return to the FEL code in the BROM is done at runtime. Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com> [hdegoede@redhat.com: Since we now restore various regs before returning to the FEL BROM code we can drop the sunxi specific #ifdefs in start.S] Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
43 lines
951 B
ArmAsm
43 lines
951 B
ArmAsm
/*
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* Utility functions for FEL mode.
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*
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* Copyright (c) 2015 Google, Inc
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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, =fel_stash
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str sp, [r0, #0]
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str lr, [r0, #4]
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mrs lr, cpsr @ Read CPSR
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str lr, [r0, #8]
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mrc p15, 0, lr, c1, c0, 0 @ Read CP15 SCTLR Register
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str lr, [r0, #12]
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mrc p15, 0, lr, c12, c0, 0 @ Read VBAR
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str lr, [r0, #16]
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mrc p15, 0, lr, c1, c0, 0 @ Read CP15 Control Register
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str lr, [r0, #20]
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b save_boot_params_ret
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ENDPROC(save_boot_params)
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ENTRY(return_to_fel)
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mov sp, r0
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mov lr, r1
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ldr r0, =fel_stash
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ldr r1, [r0, #20]
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mcr p15, 0, r1, c1, c0, 0 @ Write CP15 Control Register
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ldr r1, [r0, #16]
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mcr p15, 0, r1, c12, c0, 0 @ Write VBAR
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ldr r1, [r0, #12]
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mcr p15, 0, r1, c1, c0, 0 @ Write CP15 SCTLR Register
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ldr r1, [r0, #8]
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msr cpsr, r1 @ Write CPSR
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bx lr
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ENDPROC(return_to_fel)
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