u-boot/arch/arm/cpu/armv7/start.S

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/*
* armboot - Startup Code for OMAP3530/ARM Cortex CPU-core
*
* Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com>
*
* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
* Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
* Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
* Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
* Copyright (c) 2003 Kshitij <kshitij@ti.com>
* Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/system.h>
#include <linux/linkage.h>
#include <asm/armv7.h>
/*************************************************************************
*
* Startup Code (reset vector)
*
* Do important init only if we don't start from memory!
* Setup memory and board specific bits prior to relocation.
* Relocate armboot to ram. Setup stack.
*
*************************************************************************/
.globl reset
.globl save_boot_params_ret
#ifdef CONFIG_ARMV7_LPAE
.global switch_to_hypervisor_ret
#endif
reset:
/* Allow the board to save important registers */
b save_boot_params
save_boot_params_ret:
#ifdef CONFIG_ARMV7_LPAE
/*
* check for Hypervisor support
*/
mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
and r0, r0, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
cmp r0, #(1 << CPUID_ARM_VIRT_SHIFT)
beq switch_to_hypervisor
switch_to_hypervisor_ret:
#endif
/*
* disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
* except if in HYP mode already
*/
mrs r0, cpsr
and r1, r0, #0x1f @ mask mode bits
teq r1, #0x1a @ test for HYP mode
bicne r0, r0, #0x1f @ clear all mode bits
orrne r0, r0, #0x13 @ set SVC mode
orr r0, r0, #0xc0 @ disable FIQ and IRQ
msr cpsr,r0
/*
* Setup vector:
* (OMAP4 spl TEXT_BASE is not 32 byte aligned.
* Continue to use ROM code vector only in OMAP4 spl)
*/
#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
/* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */
mrc p15, 0, r0, c1, c0, 0 @ Read CP15 SCTLR Register
bic r0, #CR_V @ V = 0
mcr p15, 0, r0, c1, c0, 0 @ Write CP15 SCTLR Register
/* Set vector address in CP15 VBAR register */
ldr r0, =_start
mcr p15, 0, r0, c12, c0, 0 @Set VBAR
#endif
/* the mask ROM code should have PLL and others stable */
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_cp15
#ifndef CONFIG_SKIP_LOWLEVEL_INIT_ONLY
bl cpu_init_crit
#endif
#endif
bl _main
/*------------------------------------------------------------------------------*/
ENTRY(c_runtime_cpu_setup)
/*
* If I-cache is enabled invalidate it
*/
#ifndef CONFIG_SYS_ICACHE_OFF
mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
mcr p15, 0, r0, c7, c10, 4 @ DSB
mcr p15, 0, r0, c7, c5, 4 @ ISB
#endif
bx lr
ENDPROC(c_runtime_cpu_setup)
/*************************************************************************
*
* void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
* __attribute__((weak));
*
* Stack pointer is not yet initialized at this moment
* Don't save anything to stack even if compiled with -O0
*
*************************************************************************/
ENTRY(save_boot_params)
b save_boot_params_ret @ back to my caller
ENDPROC(save_boot_params)
.weak save_boot_params
#ifdef CONFIG_ARMV7_LPAE
ENTRY(switch_to_hypervisor)
b switch_to_hypervisor_ret
ENDPROC(switch_to_hypervisor)
.weak switch_to_hypervisor
#endif
/*************************************************************************
*
* cpu_init_cp15
*
* Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
* CONFIG_SYS_ICACHE_OFF is defined.
*
*************************************************************************/
ENTRY(cpu_init_cp15)
/*
* Invalidate L1 I/D
*/
mov r0, #0 @ set up for MCR
mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
mcr p15, 0, r0, c7, c5, 6 @ invalidate BP array
mcr p15, 0, r0, c7, c10, 4 @ DSB
mcr p15, 0, r0, c7, c5, 4 @ ISB
/*
* disable MMU stuff and caches
*/
mrc p15, 0, r0, c1, c0, 0
bic r0, r0, #0x00002000 @ clear bits 13 (--V-)
bic r0, r0, #0x00000007 @ clear bits 2:0 (-CAM)
orr r0, r0, #0x00000002 @ set bit 1 (--A-) Align
orr r0, r0, #0x00000800 @ set bit 11 (Z---) BTB
#ifdef CONFIG_SYS_ICACHE_OFF
bic r0, r0, #0x00001000 @ clear bit 12 (I) I-cache
#else
orr r0, r0, #0x00001000 @ set bit 12 (I) I-cache
#endif
mcr p15, 0, r0, c1, c0, 0
#ifdef CONFIG_ARM_ERRATA_716044
mrc p15, 0, r0, c1, c0, 0 @ read system control register
orr r0, r0, #1 << 11 @ set bit #11
mcr p15, 0, r0, c1, c0, 0 @ write system control register
#endif
#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072))
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 4 @ set bit #4
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_743622
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 6 @ set bit #6
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_751472
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 11 @ set bit #11
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_761320
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 21 @ set bit #21
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
#endif
mov r5, lr @ Store my Caller
mrc p15, 0, r1, c0, c0, 0 @ r1 has Read Main ID Register (MIDR)
mov r3, r1, lsr #20 @ get variant field
and r3, r3, #0xf @ r3 has CPU variant
and r4, r1, #0xf @ r4 has CPU revision
mov r2, r3, lsl #4 @ shift variant field for combined value
orr r2, r4, r2 @ r2 has combined CPU variant + revision
#ifdef CONFIG_ARM_ERRATA_798870
cmp r2, #0x30 @ Applies to lower than R3p0
bge skip_errata_798870 @ skip if not affected rev
cmp r2, #0x20 @ Applies to including and above R2p0
blt skip_errata_798870 @ skip if not affected rev
mrc p15, 1, r0, c15, c0, 0 @ read l2 aux ctrl reg
orr r0, r0, #1 << 7 @ Enable hazard-detect timeout
push {r1-r5} @ Save the cpu info registers
bl v7_arch_cp15_set_l2aux_ctrl
isb @ Recommended ISB after l2actlr update
pop {r1-r5} @ Restore the cpu info - fall through
skip_errata_798870:
#endif
ARM: Introduce erratum workaround for 801819 Add workaround for Cortex-A15 ARM erratum 801819 which says in summary that "A livelock can occur in the L2 cache arbitration that might prevent a snoop from completing. Under certain conditions this can cause the system to deadlock. " Recommended workaround is as follows: Do both of the following: 1) Do not use the write-back no-allocate memory type. 2) Do not issue write-back cacheable stores at any time when the cache is disabled (SCTLR.C=0) and the MMU is enabled (SCTLR.M=1). Because it is implementation defined whether cacheable stores update the cache when the cache is disabled it is not expected that any portable code will execute cacheable stores when the cache is disabled. For implementations of Cortex-A15 configured without the “L2 arbitration register slice” option (typically one or two core systems), you must also do the following: 3) Disable write-streaming in each CPU by setting ACTLR[28:25] = 0b1111 So, we provide an option to disable write streaming on OMAP5 and DRA7. It is a rare condition to occur and may be enabled selectively based on platform acceptance of risk. Applies to: A15 revisions r2p0, r2p1, r2p2, r2p3 or r2p4 and REVIDR[3] is set to 0. Note: certain unicore SoCs *might* not have REVIDR[3] not set, but might not meet the condition for the erratum to occur when they donot have ACP (Accelerator Coherency Port) hooked to ACE (AXI Coherency Extensions). Such SoCs will need the work around handled in the SoC specific manner, since there is no ARM generic manner to detect such configurations. Based on ARM errata Document revision 18.0 (22 Nov 2013) Suggested-by: Richard Woodruff <r-woodruff2@ti.com> Suggested-by: Brad Griffis <bgriffis@ti.com> Reviewed-by: Brad Griffis <bgriffis@ti.com> Signed-off-by: Nishanth Menon <nm@ti.com>
2015-07-27 21:26:05 +00:00
#ifdef CONFIG_ARM_ERRATA_801819
cmp r2, #0x24 @ Applies to lt including R2p4
bgt skip_errata_801819 @ skip if not affected rev
cmp r2, #0x20 @ Applies to including and above R2p0
blt skip_errata_801819 @ skip if not affected rev
mrc p15, 0, r0, c0, c0, 6 @ pick up REVIDR reg
and r0, r0, #1 << 3 @ check REVIDR[3]
cmp r0, #1 << 3
beq skip_errata_801819 @ skip erratum if REVIDR[3] is set
mrc p15, 0, r0, c1, c0, 1 @ read auxilary control register
orr r0, r0, #3 << 27 @ Disables streaming. All write-allocate
@ lines allocate in the L1 or L2 cache.
orr r0, r0, #3 << 25 @ Disables streaming. All write-allocate
@ lines allocate in the L1 cache.
push {r1-r5} @ Save the cpu info registers
bl v7_arch_cp15_set_acr
pop {r1-r5} @ Restore the cpu info - fall through
skip_errata_801819:
#endif
#ifdef CONFIG_ARM_ERRATA_454179
cmp r2, #0x21 @ Only on < r2p1
bge skip_errata_454179
mrc p15, 0, r0, c1, c0, 1 @ Read ACR
orr r0, r0, #(0x3 << 6) @ Set DBSM(BIT7) and IBE(BIT6) bits
push {r1-r5} @ Save the cpu info registers
bl v7_arch_cp15_set_acr
pop {r1-r5} @ Restore the cpu info - fall through
skip_errata_454179:
#endif
#ifdef CONFIG_ARM_ERRATA_430973
cmp r2, #0x21 @ Only on < r2p1
bge skip_errata_430973
mrc p15, 0, r0, c1, c0, 1 @ Read ACR
orr r0, r0, #(0x1 << 6) @ Set IBE bit
push {r1-r5} @ Save the cpu info registers
bl v7_arch_cp15_set_acr
pop {r1-r5} @ Restore the cpu info - fall through
skip_errata_430973:
#endif
#ifdef CONFIG_ARM_ERRATA_621766
cmp r2, #0x21 @ Only on < r2p1
bge skip_errata_621766
mrc p15, 0, r0, c1, c0, 1 @ Read ACR
orr r0, r0, #(0x1 << 5) @ Set L1NEON bit
push {r1-r5} @ Save the cpu info registers
bl v7_arch_cp15_set_acr
pop {r1-r5} @ Restore the cpu info - fall through
skip_errata_621766:
#endif
mov pc, r5 @ back to my caller
ENDPROC(cpu_init_cp15)
#if !defined(CONFIG_SKIP_LOWLEVEL_INIT) && \
!defined(CONFIG_SKIP_LOWLEVEL_INIT_ONLY)
/*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************/
ENTRY(cpu_init_crit)
/*
* Jump to board specific initialization...
* The Mask ROM will have already initialized
* basic memory. Go here to bump up clock rate and handle
* wake up conditions.
*/
b lowlevel_init @ go setup pll,mux,memory
ENDPROC(cpu_init_crit)
#endif