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https://source.denx.de/u-boot/u-boot.git
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508f75afb5
The ARMv7 start code has support for saving some boot params at the entry point, which is used by some SoCs to return to BROM. Port this to ARM926EJ-S start code. Signed-off-by: Icenowy Zheng <icenowy@aosc.io> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
132 lines
3.4 KiB
ArmAsm
132 lines
3.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* armboot - Startup Code for ARM926EJS CPU-core
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*
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* Copyright (c) 2003 Texas Instruments
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*
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* ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
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*
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* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
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* Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
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* Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
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* Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
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* Copyright (c) 2003 Kshitij <kshitij@ti.com>
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* Copyright (c) 2010 Albert Aribaud <albert.u.boot@aribaud.net>
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*/
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#include <asm-offsets.h>
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#include <config.h>
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#include <common.h>
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#include <linux/linkage.h>
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/*
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*************************************************************************
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*
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* Startup Code (reset vector)
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*
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* do important init only if we don't start from memory!
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* setup Memory and board specific bits prior to relocation.
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* relocate armboot to ram
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* setup stack
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*
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*************************************************************************
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*/
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.globl reset
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.globl save_boot_params_ret
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.type save_boot_params_ret,%function
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reset:
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/* Allow the board to save important registers */
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b save_boot_params
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save_boot_params_ret:
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/*
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* set the cpu to SVC32 mode
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*/
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mrs r0,cpsr
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bic r0,r0,#0x1f
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orr r0,r0,#0xd3
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msr cpsr,r0
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/*
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* we do sys-critical inits only at reboot,
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* not when booting from ram!
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*/
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#if !CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT)
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bl cpu_init_crit
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#endif
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bl _main
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/*------------------------------------------------------------------------------*/
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.globl c_runtime_cpu_setup
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c_runtime_cpu_setup:
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bx lr
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/*
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*************************************************************************
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*
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* CPU_init_critical registers
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*
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* setup important registers
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* setup memory timing
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*
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*************************************************************************
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*/
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#if !CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT)
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cpu_init_crit:
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/*
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* flush D cache before disabling it
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*/
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mov r0, #0
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flush_dcache:
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mrc p15, 0, r15, c7, c10, 3
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bne flush_dcache
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mcr p15, 0, r0, c8, c7, 0 /* invalidate TLB */
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mcr p15, 0, r0, c7, c5, 0 /* invalidate I Cache */
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/*
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* disable MMU and D cache
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* enable I cache if SYS_ICACHE_OFF is not defined
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*/
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mrc p15, 0, r0, c1, c0, 0
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bic r0, r0, #0x00000300 /* clear bits 9:8 (---- --RS) */
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bic r0, r0, #0x00000087 /* clear bits 7, 2:0 (B--- -CAM) */
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#ifdef CONFIG_SYS_EXCEPTION_VECTORS_HIGH
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orr r0, r0, #0x00002000 /* set bit 13 (--V- ----) */
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#else
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bic r0, r0, #0x00002000 /* clear bit 13 (--V- ----) */
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#endif
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orr r0, r0, #0x00000002 /* set bit 1 (A) Align */
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#if !CONFIG_IS_ENABLED(SYS_ICACHE_OFF)
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orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
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#endif
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mcr p15, 0, r0, c1, c0, 0
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#if !CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT_ONLY)
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/*
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* Go setup Memory and board specific bits prior to relocation.
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*/
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mov r4, lr /* perserve link reg across call */
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bl lowlevel_init /* go setup pll,mux,memory */
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mov lr, r4 /* restore link */
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#endif
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mov pc, lr /* back to my caller */
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#endif /* CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT) */
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/*************************************************************************
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*
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* void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
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* __attribute__((weak));
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*
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* Stack pointer is not yet initialized at this moment
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* Don't save anything to stack even if compiled with -O0
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*
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*************************************************************************/
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WEAK(save_boot_params)
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b save_boot_params_ret /* back to my caller */
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ENDPROC(save_boot_params)
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