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https://github.com/brain-hackers/u-boot-brain
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611fe09577
The original lowlevel_init function of AST2500 is written in C. However, the C runtime environment is not ready until _main execution. This patch adds the assembly version of the lowlevel_init function. Additional initialization to DRAM configuration and LPC reset source are also added. Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
42 lines
862 B
ArmAsm
42 lines
862 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright (C) ASPEED Technology Inc.
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*/
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#include <asm/arch/scu_ast2500.h>
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/* registers for low level init */
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#define SCU_PROT_KEY 0x1e6e2000
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#define SCU_VGA_HANDSHAKE 0x1e6e2040
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#define SCU_HW_STRAP 0x1e6e2070
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#define SCU_HW_STRAP_CLR 0x1e6e207c
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#define WDT3_CTRL 0x1e78504c
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.global lowlevel_init
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lowlevel_init:
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/* unlock SCU */
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ldr r0, =SCU_PROT_KEY
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ldr r1, =SCU_UNLOCK_VALUE
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str r1, [r0]
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/* set BMC FW as DRAM initializer */
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ldr r0, =SCU_VGA_HANDSHAKE
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ldr r1, [r0]
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orr r1, #0x80
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str r1, [r0]
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/* set PERST# as LPC reset source if eSPI mode is enabled*/
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ldr r0, =SCU_HW_STRAP
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ldr r1, [r0]
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tst r1, #(0x1 << 25)
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ldrne r0, =SCU_HW_STRAP_CLR
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movne r1, #(0x1 << 14)
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strne r1, [r0]
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/* disable WDT3 for SPI 3/4 bytes auto-detection */
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ldr r0, =WDT3_CTRL
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mov r1, #0x0
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str r1, [r0]
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mov pc, lr
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