156 lines
3.8 KiB
ArmAsm
156 lines
3.8 KiB
ArmAsm
/*
|
|
* linux/arch/arm/mm/proc-v7m.S
|
|
*
|
|
* Copyright (C) 2008 ARM Ltd.
|
|
* Copyright (C) 2001 Deep Blue Solutions Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This is the "shell" of the ARMv7-M processor support.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/memory.h>
|
|
#include <asm/v7m.h>
|
|
#include "proc-macros.S"
|
|
|
|
ENTRY(cpu_v7m_proc_init)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_proc_init)
|
|
|
|
ENTRY(cpu_v7m_proc_fin)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_proc_fin)
|
|
|
|
/*
|
|
* cpu_v7m_reset(loc)
|
|
*
|
|
* Perform a soft reset of the system. Put the CPU into the
|
|
* same state as it would be if it had been reset, and branch
|
|
* to what would be the reset vector.
|
|
*
|
|
* - loc - location to jump to for soft reset
|
|
*/
|
|
.align 5
|
|
ENTRY(cpu_v7m_reset)
|
|
ret r0
|
|
ENDPROC(cpu_v7m_reset)
|
|
|
|
/*
|
|
* cpu_v7m_do_idle()
|
|
*
|
|
* Idle the processor (eg, wait for interrupt).
|
|
*
|
|
* IRQs are already disabled.
|
|
*/
|
|
ENTRY(cpu_v7m_do_idle)
|
|
wfi
|
|
ret lr
|
|
ENDPROC(cpu_v7m_do_idle)
|
|
|
|
ENTRY(cpu_v7m_dcache_clean_area)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_dcache_clean_area)
|
|
|
|
/*
|
|
* There is no MMU, so here is nothing to do.
|
|
*/
|
|
ENTRY(cpu_v7m_switch_mm)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_switch_mm)
|
|
|
|
.globl cpu_v7m_suspend_size
|
|
.equ cpu_v7m_suspend_size, 0
|
|
|
|
#ifdef CONFIG_ARM_CPU_SUSPEND
|
|
ENTRY(cpu_v7m_do_suspend)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_do_suspend)
|
|
|
|
ENTRY(cpu_v7m_do_resume)
|
|
ret lr
|
|
ENDPROC(cpu_v7m_do_resume)
|
|
#endif
|
|
|
|
.section ".text.init", #alloc, #execinstr
|
|
|
|
/*
|
|
* __v7m_setup
|
|
*
|
|
* This should be able to cover all ARMv7-M cores.
|
|
*/
|
|
__v7m_setup:
|
|
@ Configure the vector table base address
|
|
ldr r0, =BASEADDR_V7M_SCB
|
|
ldr r12, =vector_table
|
|
str r12, [r0, V7M_SCB_VTOR]
|
|
|
|
@ enable UsageFault, BusFault and MemManage fault.
|
|
ldr r5, [r0, #V7M_SCB_SHCSR]
|
|
orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
|
|
str r5, [r0, #V7M_SCB_SHCSR]
|
|
|
|
@ Lower the priority of the SVC and PendSV exceptions
|
|
mov r5, #0x80000000
|
|
str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
|
|
mov r5, #0x00800000
|
|
str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
|
|
|
|
@ SVC to switch to handler mode. Notice that this requires sp to
|
|
@ point to writeable memory because the processor saves
|
|
@ some registers to the stack.
|
|
badr r1, 1f
|
|
ldr r5, [r12, #11 * 4] @ read the SVC vector entry
|
|
str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
|
|
mov r6, lr @ save LR
|
|
ldr sp, =init_thread_union + THREAD_START_SP
|
|
cpsie i
|
|
svc #0
|
|
1: cpsid i
|
|
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
|
|
mov lr, r6 @ restore LR
|
|
|
|
@ Special-purpose control register
|
|
mov r1, #1
|
|
msr control, r1 @ Thread mode has unpriviledged access
|
|
|
|
@ Configure the System Control Register to ensure 8-byte stack alignment
|
|
@ Note the STKALIGN bit is either RW or RAO.
|
|
ldr r12, [r0, V7M_SCB_CCR] @ system control register
|
|
orr r12, #V7M_SCB_CCR_STKALIGN
|
|
str r12, [r0, V7M_SCB_CCR]
|
|
ret lr
|
|
ENDPROC(__v7m_setup)
|
|
|
|
define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
|
|
|
|
.section ".rodata"
|
|
string cpu_arch_name, "armv7m"
|
|
string cpu_elf_name "v7m"
|
|
string cpu_v7m_name "ARMv7-M"
|
|
|
|
.section ".proc.info.init", #alloc
|
|
|
|
/*
|
|
* Match any ARMv7-M processor core.
|
|
*/
|
|
.type __v7m_proc_info, #object
|
|
__v7m_proc_info:
|
|
.long 0x000f0000 @ Required ID value
|
|
.long 0x000f0000 @ Mask for ID
|
|
.long 0 @ proc_info_list.__cpu_mm_mmu_flags
|
|
.long 0 @ proc_info_list.__cpu_io_mmu_flags
|
|
initfn __v7m_setup, __v7m_proc_info @ proc_info_list.__cpu_flush
|
|
.long cpu_arch_name
|
|
.long cpu_elf_name
|
|
.long HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT
|
|
.long cpu_v7m_name
|
|
.long v7m_processor_functions @ proc_info_list.proc
|
|
.long 0 @ proc_info_list.tlb
|
|
.long 0 @ proc_info_list.user
|
|
.long nop_cache_fns @ proc_info_list.cache
|
|
.size __v7m_proc_info, . - __v7m_proc_info
|
|
|