mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-07-09 04:36:16 +09:00
b5bd09820c
At present CONFIG_SKIP_LOWLEVEL_INIT prevents U-Boot from calling lowlevel_init(). This means that the instruction cache is not enabled and the board runs very slowly. What is really needed in many cases is to skip the call to lowlevel_init() but still perform CP15 init. Add an option to handle this. Reviewed-by: Heiko Schocher <hs@denx.de> Tested-on: smartweb, corvus, taurus, axm Tested-by: Heiko Schocher <hs@denx.de> Reviewed-by: Joe Hershberger <joe.hershberger@ni.com> Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Andreas Bießmann <andreas@biessmann.org>
96 lines
2.4 KiB
ArmAsm
96 lines
2.4 KiB
ArmAsm
/*
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* armboot - Startup Code for OMP2420/ARM1136 CPU-core
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*
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* Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com>
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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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*
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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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/*
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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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reset:
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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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/* the mask ROM code should have PLL and others stable */
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#ifndef CONFIG_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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#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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cpu_init_crit:
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/*
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* flush v4 I/D caches
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*/
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mov r0, #0
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mcr p15, 0, r0, c7, c7, 0 /* Invalidate I+D+BTB caches */
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mcr p15, 0, r0, c8, c7, 0 /* Invalidate Unified TLB */
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/*
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* disable MMU stuff and caches
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*/
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mrc p15, 0, r0, c1, c0, 0
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bic r0, r0, #0x00002300 @ clear bits 13, 9:8 (--V- --RS)
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bic r0, r0, #0x00000087 @ clear bits 7, 2:0 (B--- -CAM)
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orr r0, r0, #0x00000002 @ set bit 1 (A) Align
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orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache
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mcr p15, 0, r0, c1, c0, 0
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
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/*
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* Jump to board specific initialization... The Mask ROM will have already initialized
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* basic memory. Go here to bump up clock rate and handle wake up conditions.
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*/
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mov ip, lr /* persevere link reg across call */
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bl lowlevel_init /* go setup pll,mux,memory */
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mov lr, ip /* restore link */
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#endif
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mov pc, lr /* back to my caller */
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#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
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