The back-to-bootrom implementation for Rockchip has always relied on the stack-pointer being valid on entry, so there was little reason to have this as an assembly implementation. This provides a new C-only implementation of save_boot_params and back_to_bootrom (relying on setjmp/longjmp) and removes the older assembly-only implementation. Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Tested-by: Andy Yan <andy.yan@rock-chips.com>
66 lines
1.4 KiB
C
66 lines
1.4 KiB
C
/**
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* Copyright (c) 2017 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 <common.h>
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#include <asm/arch/bootrom.h>
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#include <asm/setjmp.h>
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#include <asm/system.h>
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/*
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* Force the jmp_buf to the data-section, as .bss will not be valid
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* when save_boot_params is invoked.
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*/
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static jmp_buf brom_ctx __section(".data");
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void back_to_bootrom(void)
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{
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#if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
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puts("Returning to boot ROM...\n");
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#endif
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longjmp(brom_ctx, BROM_BOOT_NEXTSTAGE);
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}
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/*
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* All Rockchip BROM implementations enter with a valid stack-pointer,
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* so this can safely be implemented in C (providing a single
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* implementation both for ARMv7 and AArch64).
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*/
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int save_boot_params(void)
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{
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int ret = setjmp(brom_ctx);
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switch (ret) {
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case 0:
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/*
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* This is the initial pass through this function
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* (i.e. saving the context), setjmp just setup up the
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* brom_ctx: transfer back into the startup-code at
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* 'save_boot_params_ret' and let the compiler know
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* that this will not return.
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*/
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save_boot_params_ret();
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while (true)
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/* does not return */;
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break;
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case BROM_BOOT_NEXTSTAGE:
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/*
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* To instruct the BROM to boot the next stage, we
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* need to return 0 to it: i.e. we need to rewrite
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* the return code once more.
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*/
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ret = 0;
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break;
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default:
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#if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
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puts("FATAL: unexpected command to back_to_bootrom()\n");
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#endif
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hang();
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};
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return ret;
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}
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