mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-21 10:01:00 +00:00
Code Issues Releases Wiki Activity

Merge branch 'depends/rmk-devel-stable' into next/soc

Browse source 
Pulling in base dependencies from rmk's devel-stable branch needed by the
CCI patches for vexpress.

Signed-off-by: Olof Johansson <olof@lixom.net>

* depends/rmk-devel-stable:
  ARM: Enable selection of SMP operations at boot time
  arm: introduce psci_smp_ops
  ARM: ARMv7-M: implement read_cpuid_ext
  ARM: ARMv7-M: Allow the building of new kernel port
  ARM: ARMv7-M: Add support for exception handling
  ARM: Add base support for ARMv7-M
This commit is contained in:
Olof Johansson 2013-05-31 23:37:22 -07:00
commit 6678e38959
32 changed files with 855 additions and 87 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
arch/arm/Kconfig
View file

@ -9,7 +9,7 @@ config ARM
select BUILDTIME_EXTABLE_SORT if MMU
select CPU_PM if (SUSPEND || CPU_IDLE)
select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN && MMU
select GENERIC_ATOMIC64 if (CPU_V6 || !CPU_32v6K || !AEABI)
select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
@ -1586,7 +1586,7 @@ config SCHED_HRTICK
config THUMB2_KERNEL
bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
depends on CPU_V7 && !CPU_V6 && !CPU_V6K
depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
default y if CPU_THUMBONLY
select AEABI
select ARM_ASM_UNIFIED

2
arch/arm/Kconfig-nommu
View file

@ -28,7 +28,7 @@ config FLASH_SIZE
config PROCESSOR_ID
hex 'Hard wire the processor ID'
default 0x00007700
depends on !CPU_CP15
depends on !(CPU_CP15 || CPU_V7M)
help
If processor has no CP15 register, this processor ID is
used instead of the auto-probing which utilizes the register.

1
arch/arm/Makefile
View file

@ -59,6 +59,7 @@ comma = ,
# Note that GCC does not numerically define an architecture version
# macro, but instead defines a whole series of macros which makes
# testing for a specific architecture or later rather impossible.
arch-$(CONFIG_CPU_32v7M) :=-D__LINUX_ARM_ARCH__=7 -march=armv7-m -Wa,-march=armv7-m
arch-$(CONFIG_CPU_32v7) :=-D__LINUX_ARM_ARCH__=7 $(call cc-option,-march=armv7-a,-march=armv5t -Wa$(comma)-march=armv7-a)
arch-$(CONFIG_CPU_32v6) :=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6,-march=armv5t -Wa$(comma)-march=armv6)
# Only override the compiler option if ARMv6. The ARMv6K extensions are

17
arch/arm/include/asm/assembler.h
View file

@ -136,7 +136,11 @@
* assumes FIQs are enabled, and that the processor is in SVC mode.
*/
.macro save_and_disable_irqs, oldcpsr
#ifdef CONFIG_CPU_V7M
mrs \oldcpsr, primask
#else
mrs \oldcpsr, cpsr
#endif
disable_irq
.endm
@ -150,7 +154,11 @@
* guarantee that this will preserve the flags.
*/
.macro restore_irqs_notrace, oldcpsr
#ifdef CONFIG_CPU_V7M
msr primask, \oldcpsr
#else
msr cpsr_c, \oldcpsr
#endif
.endm
.macro restore_irqs, oldcpsr
@ -229,7 +237,14 @@
#endif
.endm
#ifdef CONFIG_THUMB2_KERNEL
#if defined(CONFIG_CPU_V7M)
/*
* setmode is used to assert to be in svc mode during boot. For v7-M
* this is done in __v7m_setup, so setmode can be empty here.
*/
.macro setmode, mode, reg
.endm
#elif defined(CONFIG_THUMB2_KERNEL)
.macro setmode, mode, reg
mov \reg, #\mode
msr cpsr_c, \reg

44
arch/arm/include/asm/cputype.h
View file

@ -10,6 +10,22 @@
#define CPUID_TLBTYPE 3
#define CPUID_MPIDR 5
#ifdef CONFIG_CPU_V7M
#define CPUID_EXT_PFR0 0x40
#define CPUID_EXT_PFR1 0x44
#define CPUID_EXT_DFR0 0x48
#define CPUID_EXT_AFR0 0x4c
#define CPUID_EXT_MMFR0 0x50
#define CPUID_EXT_MMFR1 0x54
#define CPUID_EXT_MMFR2 0x58
#define CPUID_EXT_MMFR3 0x5c
#define CPUID_EXT_ISAR0 0x60
#define CPUID_EXT_ISAR1 0x64
#define CPUID_EXT_ISAR2 0x68
#define CPUID_EXT_ISAR3 0x6c
#define CPUID_EXT_ISAR4 0x70
#define CPUID_EXT_ISAR5 0x74
#else
#define CPUID_EXT_PFR0 "c1, 0"
#define CPUID_EXT_PFR1 "c1, 1"
#define CPUID_EXT_DFR0 "c1, 2"
@ -24,6 +40,7 @@
#define CPUID_EXT_ISAR3 "c2, 3"
#define CPUID_EXT_ISAR4 "c2, 4"
#define CPUID_EXT_ISAR5 "c2, 5"
#endif
#define MPIDR_SMP_BITMASK (0x3 << 30)
#define MPIDR_SMP_VALUE (0x2 << 30)
@ -79,7 +96,23 @@ extern unsigned int processor_id;
__val; \
})
#else /* ifdef CONFIG_CPU_CP15 */
#elif defined(CONFIG_CPU_V7M)
#include <asm/io.h>
#include <asm/v7m.h>
#define read_cpuid(reg) \
({ \
WARN_ON_ONCE(1); \
0; \
})
static inline unsigned int __attribute_const__ read_cpuid_ext(unsigned offset)
{
return readl(BASEADDR_V7M_SCB + offset);
}
#else /* ifdef CONFIG_CPU_CP15 / elif defined (CONFIG_CPU_V7M) */
/*
* read_cpuid and read_cpuid_ext should only ever be called on machines that
@ -106,7 +139,14 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
return read_cpuid(CPUID_ID);
}
#else /* ifdef CONFIG_CPU_CP15 */
#elif defined(CONFIG_CPU_V7M)
static inline unsigned int __attribute_const__ read_cpuid_id(void)
{
return readl(BASEADDR_V7M_SCB + V7M_SCB_CPUID);
}
#else /* ifdef CONFIG_CPU_CP15 / elif defined(CONFIG_CPU_V7M) */
static inline unsigned int __attribute_const__ read_cpuid_id(void)
{

27
arch/arm/include/asm/glue-cache.h
View file

@ -117,10 +117,37 @@
# endif
#endif
#if defined(CONFIG_CPU_V7M)
# ifdef _CACHE
# define MULTI_CACHE 1
# else
# define _CACHE nop
# endif
#endif
#if !defined(_CACHE) && !defined(MULTI_CACHE)
#error Unknown cache maintenance model
#endif
#ifndef __ASSEMBLER__
extern inline void nop_flush_icache_all(void) { }
extern inline void nop_flush_kern_cache_all(void) { }
extern inline void nop_flush_kern_cache_louis(void) { }
extern inline void nop_flush_user_cache_all(void) { }
extern inline void nop_flush_user_cache_range(unsigned long a,
unsigned long b, unsigned int c) { }
extern inline void nop_coherent_kern_range(unsigned long a, unsigned long b) { }
extern inline int nop_coherent_user_range(unsigned long a,
unsigned long b) { return 0; }
extern inline void nop_flush_kern_dcache_area(void *a, size_t s) { }
extern inline void nop_dma_flush_range(const void *a, const void *b) { }
extern inline void nop_dma_map_area(const void *s, size_t l, int f) { }
extern inline void nop_dma_unmap_area(const void *s, size_t l, int f) { }
#endif
#ifndef MULTI_CACHE
#define __cpuc_flush_icache_all __glue(_CACHE,_flush_icache_all)
#define __cpuc_flush_kern_all __glue(_CACHE,_flush_kern_cache_all)

8
arch/arm/include/asm/glue-df.h
View file

@ -95,6 +95,14 @@
# endif
#endif
#ifdef CONFIG_CPU_ABRT_NOMMU
# ifdef CPU_DABORT_HANDLER
# define MULTI_DABORT 1
# else
# define CPU_DABORT_HANDLER nommu_early_abort
# endif
#endif
#ifndef CPU_DABORT_HANDLER
#error Unknown data abort handler type
#endif

9
arch/arm/include/asm/glue-proc.h
View file

@ -230,6 +230,15 @@
# endif
#endif
#ifdef CONFIG_CPU_V7M
# ifdef CPU_NAME
# undef MULTI_CPU
# define MULTI_CPU
# else
# define CPU_NAME cpu_v7m
# endif
#endif
#ifndef MULTI_CPU
#define cpu_proc_init __glue(CPU_NAME,_proc_init)
#define cpu_proc_fin __glue(CPU_NAME,_proc_fin)

22
arch/arm/include/asm/irqflags.h
View file

@ -8,6 +8,16 @@
/*
* CPU interrupt mask handling.
*/
#ifdef CONFIG_CPU_V7M
#define IRQMASK_REG_NAME_R "primask"
#define IRQMASK_REG_NAME_W "primask"
#define IRQMASK_I_BIT 1
#else
#define IRQMASK_REG_NAME_R "cpsr"
#define IRQMASK_REG_NAME_W "cpsr_c"
#define IRQMASK_I_BIT PSR_I_BIT
#endif
#if __LINUX_ARM_ARCH__ >= 6
static inline unsigned long arch_local_irq_save(void)
@ -15,7 +25,7 @@ static inline unsigned long arch_local_irq_save(void)
unsigned long flags;
asm volatile(
" mrs %0, cpsr @ arch_local_irq_save\n"
" mrs %0, " IRQMASK_REG_NAME_R " @ arch_local_irq_save\n"
" cpsid i"
: "=r" (flags) : : "memory", "cc");
return flags;
@ -129,7 +139,7 @@ static inline unsigned long arch_local_save_flags(void)
{
unsigned long flags;
asm volatile(
" mrs %0, cpsr @ local_save_flags"
" mrs %0, " IRQMASK_REG_NAME_R " @ local_save_flags"
: "=r" (flags) : : "memory", "cc");
return flags;
}
@ -140,7 +150,7 @@ static inline unsigned long arch_local_save_flags(void)
static inline void arch_local_irq_restore(unsigned long flags)
{
asm volatile(
" msr cpsr_c, %0 @ local_irq_restore"
" msr " IRQMASK_REG_NAME_W ", %0 @ local_irq_restore"
:
: "r" (flags)
: "memory", "cc");
@ -148,8 +158,8 @@ static inline void arch_local_irq_restore(unsigned long flags)
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
return flags & PSR_I_BIT;
return flags & IRQMASK_I_BIT;
}
#endif
#endif
#endif /* ifdef __KERNEL__ */
#endif /* ifndef __ASM_ARM_IRQFLAGS_H */

5
arch/arm/include/asm/mach/arch.h
View file

@ -8,6 +8,8 @@
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#ifndef __ASSEMBLY__
struct tag;
@ -16,8 +18,10 @@ struct pt_regs;
struct smp_operations;
#ifdef CONFIG_SMP
#define smp_ops(ops) (&(ops))
#define smp_init_ops(ops) (&(ops))
#else
#define smp_ops(ops) (struct smp_operations *)NULL
#define smp_init_ops(ops) (bool (*)(void))NULL
#endif
struct machine_desc {
@ -41,6 +45,7 @@ struct machine_desc {
unsigned char reserve_lp2 :1; /* never has lp2 */
char restart_mode; /* default restart mode */
struct smp_operations *smp; /* SMP operations */
bool (*smp_init)(void);
void (*fixup)(struct tag *, char **,
struct meminfo *);
void (*reserve)(void);/* reserve mem blocks */

9
arch/arm/include/asm/psci.h
View file

@ -32,5 +32,14 @@ struct psci_operations {
};
extern struct psci_operations psci_ops;
extern struct smp_operations psci_smp_ops;
#ifdef CONFIG_ARM_PSCI
void psci_init(void);
bool psci_smp_available(void);
#else
static inline void psci_init(void) { }
static inline bool psci_smp_available(void) { return false; }
#endif
#endif /* __ASM_ARM_PSCI_H */

4
arch/arm/include/asm/ptrace.h
View file

@ -45,6 +45,7 @@ struct pt_regs {
*/
static inline int valid_user_regs(struct pt_regs *regs)
{
#ifndef CONFIG_CPU_V7M
unsigned long mode = regs->ARM_cpsr & MODE_MASK;
/*
@ -67,6 +68,9 @@ static inline int valid_user_regs(struct pt_regs *regs)
regs->ARM_cpsr |= USR_MODE;
return 0;
#else /* ifndef CONFIG_CPU_V7M */
return 1;
#endif
}
static inline long regs_return_value(struct pt_regs *regs)

1
arch/arm/include/asm/system_info.h
View file

@ -11,6 +11,7 @@
#define CPU_ARCH_ARMv5TEJ 7
#define CPU_ARCH_ARMv6 8
#define CPU_ARCH_ARMv7 9
#define CPU_ARCH_ARMv7M 10
#ifndef __ASSEMBLY__

44
arch/arm/include/asm/v7m.h Normal file
View file

@ -0,0 +1,44 @@
/*
* Common defines for v7m cpus
*/
#define V7M_SCS_ICTR IOMEM(0xe000e004)
#define V7M_SCS_ICTR_INTLINESNUM_MASK 0x0000000f
#define BASEADDR_V7M_SCB IOMEM(0xe000ed00)
#define V7M_SCB_CPUID 0x00
#define V7M_SCB_ICSR 0x04
#define V7M_SCB_ICSR_PENDSVSET (1 << 28)
#define V7M_SCB_ICSR_PENDSVCLR (1 << 27)
#define V7M_SCB_ICSR_RETTOBASE (1 << 11)
#define V7M_SCB_VTOR 0x08
#define V7M_SCB_SCR 0x10
#define V7M_SCB_SCR_SLEEPDEEP (1 << 2)
#define V7M_SCB_CCR 0x14
#define V7M_SCB_CCR_STKALIGN (1 << 9)
#define V7M_SCB_SHPR2 0x1c
#define V7M_SCB_SHPR3 0x20
#define V7M_SCB_SHCSR 0x24
#define V7M_SCB_SHCSR_USGFAULTENA (1 << 18)
#define V7M_SCB_SHCSR_BUSFAULTENA (1 << 17)
#define V7M_SCB_SHCSR_MEMFAULTENA (1 << 16)
#define V7M_xPSR_FRAMEPTRALIGN 0x00000200
#define V7M_xPSR_EXCEPTIONNO 0x000001ff
/*
* When branching to an address that has bits [31:28] == 0xf an exception return
* occurs. Bits [27:5] are reserved (SBOP). If the processor implements the FP
* extension Bit [4] defines if the exception frame has space allocated for FP
* state information, SBOP otherwise. Bit [3] defines the mode that is returned
* to (0 -> handler mode; 1 -> thread mode). Bit [2] defines which sp is used
* (0 -> msp; 1 -> psp). Bits [1:0] are fixed to 0b01.
*/
#define EXC_RET_STACK_MASK 0x00000004
#define EXC_RET_THREADMODE_PROCESSSTACK 0xfffffffd

35
arch/arm/include/uapi/asm/ptrace.h
View file

@ -34,28 +34,47 @@
/*
* PSR bits
* Note on V7M there is no mode contained in the PSR
*/
#define USR26_MODE 0x00000000
#define FIQ26_MODE 0x00000001
#define IRQ26_MODE 0x00000002
#define SVC26_MODE 0x00000003
#if defined(__KERNEL__) && defined(CONFIG_CPU_V7M)
/*
* Use 0 here to get code right that creates a userspace
* or kernel space thread.
*/
#define USR_MODE 0x00000000
#define SVC_MODE 0x00000000
#else
#define USR_MODE 0x00000010
#define SVC_MODE 0x00000013
#endif
#define FIQ_MODE 0x00000011
#define IRQ_MODE 0x00000012
#define SVC_MODE 0x00000013
#define ABT_MODE 0x00000017
#define HYP_MODE 0x0000001a
#define UND_MODE 0x0000001b
#define SYSTEM_MODE 0x0000001f
#define MODE32_BIT 0x00000010
#define MODE_MASK 0x0000001f
#define PSR_T_BIT 0x00000020
#define PSR_F_BIT 0x00000040
#define PSR_I_BIT 0x00000080
#define PSR_A_BIT 0x00000100
#define PSR_E_BIT 0x00000200
#define PSR_J_BIT 0x01000000
#define PSR_Q_BIT 0x08000000
#define V4_PSR_T_BIT 0x00000020 /* >= V4T, but not V7M */
#define V7M_PSR_T_BIT 0x01000000
#if defined(__KERNEL__) && defined(CONFIG_CPU_V7M)
#define PSR_T_BIT V7M_PSR_T_BIT
#else
/* for compatibility */
#define PSR_T_BIT V4_PSR_T_BIT
#endif
#define PSR_F_BIT 0x00000040 /* >= V4, but not V7M */
#define PSR_I_BIT 0x00000080 /* >= V4, but not V7M */
#define PSR_A_BIT 0x00000100 /* >= V6, but not V7M */
#define PSR_E_BIT 0x00000200 /* >= V6, but not V7M */
#define PSR_J_BIT 0x01000000 /* >= V5J, but not V7M */
#define PSR_Q_BIT 0x08000000 /* >= V5E, including V7M */
#define PSR_V_BIT 0x10000000
#define PSR_C_BIT 0x20000000
#define PSR_Z_BIT 0x40000000

13
arch/arm/kernel/Makefile
View file

@ -15,7 +15,7 @@ CFLAGS_REMOVE_return_address.o = -pg
# Object file lists.
obj-y := elf.o entry-armv.o entry-common.o irq.o opcodes.o \
obj-y := elf.o entry-common.o irq.o opcodes.o \
process.o ptrace.o return_address.o sched_clock.o \
setup.o signal.o stacktrace.o sys_arm.o time.o traps.o
@ -23,6 +23,12 @@ obj-$(CONFIG_ATAGS) += atags_parse.o
obj-$(CONFIG_ATAGS_PROC) += atags_proc.o
obj-$(CONFIG_DEPRECATED_PARAM_STRUCT) += atags_compat.o
ifeq ($(CONFIG_CPU_V7M),y)
obj-y += entry-v7m.o
else
obj-y += entry-armv.o
endif
obj-$(CONFIG_OC_ETM) += etm.o
obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_ISA_DMA_API) += dma.o
@ -82,6 +88,9 @@ obj-$(CONFIG_DEBUG_LL) += debug.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o
obj-$(CONFIG_ARM_PSCI) += psci.o
ifeq ($(CONFIG_ARM_PSCI),y)
obj-y += psci.o
obj-$(CONFIG_SMP) += psci_smp.o
endif
extra-y := $(head-y) vmlinux.lds

4
arch/arm/kernel/entry-common.S
View file

@ -350,6 +350,9 @@ ENDPROC(ftrace_stub)
.align 5
ENTRY(vector_swi)
#ifdef CONFIG_CPU_V7M
v7m_exception_entry
#else
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} @ Calling r0 - r12
ARM( add r8, sp, #S_PC )
@ -360,6 +363,7 @@ ENTRY(vector_swi)
str lr, [sp, #S_PC] @ Save calling PC
str r8, [sp, #S_PSR] @ Save CPSR
str r0, [sp, #S_OLD_R0] @ Save OLD_R0
#endif
zero_fp
/*

124
arch/arm/kernel/entry-header.S
View file

@ -5,6 +5,7 @@
#include <asm/asm-offsets.h>
#include <asm/errno.h>
#include <asm/thread_info.h>
#include <asm/v7m.h>
@ Bad Abort numbers
@ -----------------
@ -44,6 +45,116 @@
#endif
.endm
#ifdef CONFIG_CPU_V7M
/*
* ARMv7-M exception entry/exit macros.
*
* xPSR, ReturnAddress(), LR (R14), R12, R3, R2, R1, and R0 are
* automatically saved on the current stack (32 words) before
* switching to the exception stack (SP_main).
*
* If exception is taken while in user mode, SP_main is
* empty. Otherwise, SP_main is aligned to 64 bit automatically
* (CCR.STKALIGN set).
*
* Linux assumes that the interrupts are disabled when entering an
* exception handler and it may BUG if this is not the case. Interrupts
* are disabled during entry and reenabled in the exit macro.
*
* v7m_exception_slow_exit is used when returning from SVC or PendSV.
* When returning to kernel mode, we don't return from exception.
*/
.macro v7m_exception_entry
@ determine the location of the registers saved by the core during
@ exception entry. Depending on the mode the cpu was in when the
@ exception happend that is either on the main or the process stack.
@ Bit 2 of EXC_RETURN stored in the lr register specifies which stack
@ was used.
tst lr, #EXC_RET_STACK_MASK
mrsne r12, psp
moveq r12, sp
@ we cannot rely on r0-r3 and r12 matching the value saved in the
@ exception frame because of tail-chaining. So these have to be
@ reloaded.
ldmia r12!, {r0-r3}
@ Linux expects to have irqs off. Do it here before taking stack space
cpsid i
sub sp, #S_FRAME_SIZE-S_IP
stmdb sp!, {r0-r11}
@ load saved r12, lr, return address and xPSR.
@ r0-r7 are used for signals and never touched from now on. Clobbering
@ r8-r12 is OK.
mov r9, r12
ldmia r9!, {r8, r10-r12}
@ calculate the original stack pointer value.
@ r9 currently points to the memory location just above the auto saved
@ xPSR.
@ The cpu might automatically 8-byte align the stack. Bit 9
@ of the saved xPSR specifies if stack aligning took place. In this case
@ another 32-bit value is included in the stack.
tst r12, V7M_xPSR_FRAMEPTRALIGN
addne r9, r9, #4
@ store saved r12 using str to have a register to hold the base for stm
str r8, [sp, #S_IP]
add r8, sp, #S_SP
@ store r13-r15, xPSR
stmia r8!, {r9-r12}
@ store old_r0
str r0, [r8]
.endm
/*
* PENDSV and SVCALL are configured to have the same exception
* priorities. As a kernel thread runs at SVCALL execution priority it
* can never be preempted and so we will never have to return to a
* kernel thread here.
*/
.macro v7m_exception_slow_exit ret_r0
cpsid i
ldr lr, =EXC_RET_THREADMODE_PROCESSSTACK
@ read original r12, sp, lr, pc and xPSR
add r12, sp, #S_IP
ldmia r12, {r1-r5}
@ an exception frame is always 8-byte aligned. To tell the hardware if
@ the sp to be restored is aligned or not set bit 9 of the saved xPSR
@ accordingly.
tst r2, #4
subne r2, r2, #4
orrne r5, V7M_xPSR_FRAMEPTRALIGN
biceq r5, V7M_xPSR_FRAMEPTRALIGN
@ write basic exception frame
stmdb r2!, {r1, r3-r5}
ldmia sp, {r1, r3-r5}
.if \ret_r0
stmdb r2!, {r0, r3-r5}
.else
stmdb r2!, {r1, r3-r5}
.endif
@ restore process sp
msr psp, r2
@ restore original r4-r11
ldmia sp!, {r0-r11}
@ restore main sp
add sp, sp, #S_FRAME_SIZE-S_IP
cpsie i
bx lr
.endm
#endif /* CONFIG_CPU_V7M */
@
@ Store/load the USER SP and LR registers by switching to the SYS
@ mode. Useful in Thumb-2 mode where "stm/ldm rd, {sp, lr}^" is not
@ -165,6 +276,18 @@
rfeia sp!
.endm
#ifdef CONFIG_CPU_V7M
/*
* Note we don't need to do clrex here as clearing the local monitor is
* part of each exception entry and exit sequence.
*/
.macro restore_user_regs, fast = 0, offset = 0
.if \offset
add sp, #\offset
.endif
v7m_exception_slow_exit ret_r0 = \fast
.endm
#else /* ifdef CONFIG_CPU_V7M */
.macro restore_user_regs, fast = 0, offset = 0
clrex @ clear the exclusive monitor
mov r2, sp
@ -181,6 +304,7 @@
add sp, sp, #S_FRAME_SIZE - S_SP
movs pc, lr @ return & move spsr_svc into cpsr
.endm
#endif /* ifdef CONFIG_CPU_V7M / else */
.macro get_thread_info, rd
mov \rd, sp

143
arch/arm/kernel/entry-v7m.S Normal file
View file

@ -0,0 +1,143 @@
/*
* linux/arch/arm/kernel/entry-v7m.S
*
* Copyright (C) 2008 ARM 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.
*
* Low-level vector interface routines for the ARMv7-M architecture
*/
#include <asm/memory.h>
#include <asm/glue.h>
#include <asm/thread_notify.h>
#include <asm/v7m.h>
#include <mach/entry-macro.S>
#include "entry-header.S"
#ifdef CONFIG_TRACE_IRQFLAGS
#error "CONFIG_TRACE_IRQFLAGS not supported on the current ARMv7M implementation"
#endif
__invalid_entry:
v7m_exception_entry
adr r0, strerr
mrs r1, ipsr
mov r2, lr
bl printk
mov r0, sp
bl show_regs
1: b 1b
ENDPROC(__invalid_entry)
strerr: .asciz "\nUnhandled exception: IPSR = %08lx LR = %08lx\n"
.align 2
__irq_entry:
v7m_exception_entry
@
@ Invoke the IRQ handler
@
mrs r0, ipsr
ldr r1, =V7M_xPSR_EXCEPTIONNO
and r0, r1
sub r0, #16
mov r1, sp
stmdb sp!, {lr}
@ routine called with r0 = irq number, r1 = struct pt_regs *
bl nvic_do_IRQ
pop {lr}
@
@ Check for any pending work if returning to user
@
ldr r1, =BASEADDR_V7M_SCB
ldr r0, [r1, V7M_SCB_ICSR]
tst r0, V7M_SCB_ICSR_RETTOBASE
beq 2f
get_thread_info tsk
ldr r2, [tsk, #TI_FLAGS]
tst r2, #_TIF_WORK_MASK
beq 2f @ no work pending
mov r0, #V7M_SCB_ICSR_PENDSVSET
str r0, [r1, V7M_SCB_ICSR] @ raise PendSV
2:
@ registers r0-r3 and r12 are automatically restored on exception
@ return. r4-r7 were not clobbered in v7m_exception_entry so for
@ correctness they don't need to be restored. So only r8-r11 must be
@ restored here. The easiest way to do so is to restore r0-r7, too.
ldmia sp!, {r0-r11}
add sp, #S_FRAME_SIZE-S_IP
cpsie i
bx lr
ENDPROC(__irq_entry)
__pendsv_entry:
v7m_exception_entry
ldr r1, =BASEADDR_V7M_SCB
mov r0, #V7M_SCB_ICSR_PENDSVCLR
str r0, [r1, V7M_SCB_ICSR] @ clear PendSV
@ execute the pending work, including reschedule
get_thread_info tsk
mov why, #0
b ret_to_user
ENDPROC(__pendsv_entry)
/*
* Register switch for ARMv7-M processors.
* r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
* previous and next are guaranteed not to be the same.
*/
ENTRY(__switch_to)
.fnstart
.cantunwind
add ip, r1, #TI_CPU_SAVE
stmia ip!, {r4 - r11} @ Store most regs on stack
str sp, [ip], #4
str lr, [ip], #4
mov r5, r0
add r4, r2, #TI_CPU_SAVE
ldr r0, =thread_notify_head
mov r1, #THREAD_NOTIFY_SWITCH
bl atomic_notifier_call_chain
mov ip, r4
mov r0, r5
ldmia ip!, {r4 - r11} @ Load all regs saved previously
ldr sp, [ip]
ldr pc, [ip, #4]!
.fnend
ENDPROC(__switch_to)
.data
.align 8
/*
* Vector table (64 words => 256 bytes natural alignment)
*/
ENTRY(vector_table)
.long 0 @ 0 - Reset stack pointer
.long __invalid_entry @ 1 - Reset
.long __invalid_entry @ 2 - NMI
.long __invalid_entry @ 3 - HardFault
.long __invalid_entry @ 4 - MemManage
.long __invalid_entry @ 5 - BusFault
.long __invalid_entry @ 6 - UsageFault
.long __invalid_entry @ 7 - Reserved
.long __invalid_entry @ 8 - Reserved
.long __invalid_entry @ 9 - Reserved
.long __invalid_entry @ 10 - Reserved
.long vector_swi @ 11 - SVCall
.long __invalid_entry @ 12 - Debug Monitor
.long __invalid_entry @ 13 - Reserved
.long __pendsv_entry @ 14 - PendSV
.long __invalid_entry @ 15 - SysTick
.rept 64 - 16
.long __irq_entry @ 16..64 - External Interrupts
.endr

10
arch/arm/kernel/head-nommu.S
View file

@ -19,6 +19,7 @@
#include <asm/asm-offsets.h>
#include <asm/cp15.h>
#include <asm/thread_info.h>
#include <asm/v7m.h>
/*
* Kernel startup entry point.
@ -50,10 +51,13 @@ ENTRY(stext)
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
@ and irqs disabled
#ifndef CONFIG_CPU_CP15
ldr r9, =CONFIG_PROCESSOR_ID
#else
#if defined(CONFIG_CPU_CP15)
mrc p15, 0, r9, c0, c0 @ get processor id
#elif defined(CONFIG_CPU_V7M)
ldr r9, =BASEADDR_V7M_SCB
ldr r9, [r9, V7M_SCB_CPUID]
#else
ldr r9, =CONFIG_PROCESSOR_ID
#endif
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?

7
arch/arm/kernel/psci.c
View file

@ -158,7 +158,7 @@ static const struct of_device_id psci_of_match[] __initconst = {
{},
};
static int __init psci_init(void)
void __init psci_init(void)
{
struct device_node *np;
const char *method;
@ -166,7 +166,7 @@ static int __init psci_init(void)
np = of_find_matching_node(NULL, psci_of_match);
if (!np)
return 0;
return;
pr_info("probing function IDs from device-tree\n");
@ -206,6 +206,5 @@ static int __init psci_init(void)
out_put_node:
of_node_put(np);
return 0;
return;
}
early_initcall(psci_init);

84
arch/arm/kernel/psci_smp.c Normal file
View file

@ -0,0 +1,84 @@
/*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2012 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#include <linux/init.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/smp.h>
#include <linux/of.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
/*
* psci_smp assumes that the following is true about PSCI:
*
* cpu_suspend Suspend the execution on a CPU
* @state we don't currently describe affinity levels, so just pass 0.
* @entry_point the first instruction to be executed on return
* returns 0 success, < 0 on failure
*
* cpu_off Power down a CPU
* @state we don't currently describe affinity levels, so just pass 0.
* no return on successful call
*
* cpu_on Power up a CPU
* @cpuid cpuid of target CPU, as from MPIDR
* @entry_point the first instruction to be executed on return
* returns 0 success, < 0 on failure
*
* migrate Migrate the context to a different CPU
* @cpuid cpuid of target CPU, as from MPIDR
* returns 0 success, < 0 on failure
*
*/
extern void secondary_startup(void);
static int __cpuinit psci_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
if (psci_ops.cpu_on)
return psci_ops.cpu_on(cpu_logical_map(cpu),
__pa(secondary_startup));
return -ENODEV;
}
#ifdef CONFIG_HOTPLUG_CPU
void __ref psci_cpu_die(unsigned int cpu)
{
const struct psci_power_state ps = {
.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
};
if (psci_ops.cpu_off)
psci_ops.cpu_off(ps);
/* We should never return */
panic("psci: cpu %d failed to shutdown\n", cpu);
}
#else
#define psci_cpu_die NULL
#endif
bool __init psci_smp_available(void)
{
/* is cpu_on available at least? */
return (psci_ops.cpu_on != NULL);
}
struct smp_operations __initdata psci_smp_ops = {
.smp_boot_secondary = psci_boot_secondary,
.cpu_die = psci_cpu_die,
};

26
arch/arm/kernel/setup.c
View file

@ -37,6 +37,7 @@
#include <asm/cputype.h>
#include <asm/elf.h>
#include <asm/procinfo.h>
#include <asm/psci.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
@ -128,7 +129,9 @@ struct stack {
u32 und[3];
} ____cacheline_aligned;
#ifndef CONFIG_CPU_V7M
static struct stack stacks[NR_CPUS];
#endif
char elf_platform[ELF_PLATFORM_SIZE];
EXPORT_SYMBOL(elf_platform);
@ -207,7 +210,7 @@ static const char *proc_arch[] = {
"5TEJ",
"6TEJ",
"7",
"?(11)",
"7M",
"?(12)",
"?(13)",
"?(14)",
@ -216,6 +219,12 @@ static const char *proc_arch[] = {
"?(17)",
};
#ifdef CONFIG_CPU_V7M
static int __get_cpu_architecture(void)
{
return CPU_ARCH_ARMv7M;
}
#else
static int __get_cpu_architecture(void)
{
int cpu_arch;
@ -248,6 +257,7 @@ static int __get_cpu_architecture(void)
return cpu_arch;
}
#endif
int __pure cpu_architecture(void)
{
@ -293,7 +303,9 @@ static void __init cacheid_init(void)
{
unsigned int arch = cpu_architecture();
if (arch >= CPU_ARCH_ARMv6) {
if (arch == CPU_ARCH_ARMv7M) {
cacheid = 0;
} else if (arch >= CPU_ARCH_ARMv6) {
unsigned int cachetype = read_cpuid_cachetype();
if ((cachetype & (7 << 29)) == 4 << 29) {
/* ARMv7 register format */
@ -392,6 +404,7 @@ static void __init feat_v6_fixup(void)
*/
void notrace cpu_init(void)
{
#ifndef CONFIG_CPU_V7M
unsigned int cpu = smp_processor_id();
struct stack *stk = &stacks[cpu];
@ -442,6 +455,7 @@ void notrace cpu_init(void)
"I" (offsetof(struct stack, und[0])),
PLC (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
: "r14");
#endif
}
int __cpu_logical_map[NR_CPUS];
@ -796,9 +810,15 @@ void __init setup_arch(char **cmdline_p)
unflatten_device_tree();
arm_dt_init_cpu_maps();
psci_init();
#ifdef CONFIG_SMP
if (is_smp()) {
smp_set_ops(mdesc->smp);
if (!mdesc->smp_init || !mdesc->smp_init()) {
if (psci_smp_available())
smp_set_ops(&psci_smp_ops);
else if (mdesc->smp)
smp_set_ops(mdesc->smp);
}
smp_init_cpus();
}
#endif

8
arch/arm/kernel/traps.c
View file

@ -812,6 +812,7 @@ static void __init kuser_get_tls_init(unsigned long vectors)
void __init early_trap_init(void *vectors_base)
{
#ifndef CONFIG_CPU_V7M
unsigned long vectors = (unsigned long)vectors_base;
extern char __stubs_start[], __stubs_end[];
extern char __vectors_start[], __vectors_end[];
@ -843,4 +844,11 @@ void __init early_trap_init(void *vectors_base)
flush_icache_range(vectors, vectors + PAGE_SIZE);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
#else /* ifndef CONFIG_CPU_V7M */
/*
* on V7-M there is no need to copy the vector table to a dedicated
* memory area. The address is configurable and so a table in the kernel
* image can be used.
*/
#endif
}

1
arch/arm/mach-virt/Makefile
View file

@ -3,4 +3,3 @@
#
obj-y := virt.o
obj-$(CONFIG_SMP) += platsmp.o

50
arch/arm/mach-virt/platsmp.c
View file

@ -1,50 +0,0 @@
/*
* Dummy Virtual Machine - does what it says on the tin.
*
* Copyright (C) 2012 ARM Ltd
* Author: Will Deacon <will.deacon@arm.com>
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/of.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
extern void secondary_startup(void);
static void __init virt_smp_init_cpus(void)
{
}
static void __init virt_smp_prepare_cpus(unsigned int max_cpus)
{
}
static int __cpuinit virt_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
if (psci_ops.cpu_on)
return psci_ops.cpu_on(cpu_logical_map(cpu),
__pa(secondary_startup));
return -ENODEV;
}
struct smp_operations __initdata virt_smp_ops = {
.smp_init_cpus = virt_smp_init_cpus,
.smp_prepare_cpus = virt_smp_prepare_cpus,
.smp_boot_secondary = virt_boot_secondary,
};

3
arch/arm/mach-virt/virt.c
View file

@ -36,11 +36,8 @@ static const char *virt_dt_match[] = {
NULL
};
extern struct smp_operations virt_smp_ops;
DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
.init_irq = irqchip_init,
.init_machine = virt_init,
.smp = smp_ops(virt_smp_ops),
.dt_compat = virt_dt_match,
MACHINE_END

21
arch/arm/mm/Kconfig
View file

@ -397,6 +397,15 @@ config CPU_V7
select CPU_PABRT_V7
select CPU_TLB_V7 if MMU
# ARMv7M
config CPU_V7M
bool
select CPU_32v7M
select CPU_ABRT_NOMMU
select CPU_CACHE_NOP
select CPU_PABRT_LEGACY
select CPU_THUMBONLY
config CPU_THUMBONLY
bool
# There are no CPUs available with MMU that don't implement an ARM ISA:
@ -441,6 +450,9 @@ config CPU_32v6K
config CPU_32v7
bool
config CPU_32v7M
bool
# The abort model
config CPU_ABRT_NOMMU
bool
@ -491,6 +503,9 @@ config CPU_CACHE_V6
config CPU_CACHE_V7
bool
config CPU_CACHE_NOP
bool
config CPU_CACHE_VIVT
bool
@ -613,7 +628,11 @@ config ARCH_DMA_ADDR_T_64BIT
config ARM_THUMB
bool "Support Thumb user binaries" if !CPU_THUMBONLY
depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON
depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || \
CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || \
CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || \
CPU_V7 || CPU_FEROCEON || CPU_V7M
default y
help
Say Y if you want to include kernel support for running user space

2
arch/arm/mm/Makefile
View file

@ -39,6 +39,7 @@ obj-$(CONFIG_CPU_CACHE_V4WB) += cache-v4wb.o
obj-$(CONFIG_CPU_CACHE_V6) += cache-v6.o
obj-$(CONFIG_CPU_CACHE_V7) += cache-v7.o
obj-$(CONFIG_CPU_CACHE_FA) += cache-fa.o
obj-$(CONFIG_CPU_CACHE_NOP) += cache-nop.o
AFLAGS_cache-v6.o :=-Wa,-march=armv6
AFLAGS_cache-v7.o :=-Wa,-march=armv7-a
@ -87,6 +88,7 @@ obj-$(CONFIG_CPU_FEROCEON) += proc-feroceon.o
obj-$(CONFIG_CPU_V6) += proc-v6.o
obj-$(CONFIG_CPU_V6K) += proc-v6.o
obj-$(CONFIG_CPU_V7) += proc-v7.o
obj-$(CONFIG_CPU_V7M) += proc-v7m.o
AFLAGS_proc-v6.o :=-Wa,-march=armv6
AFLAGS_proc-v7.o :=-Wa,-march=armv7-a

50
arch/arm/mm/cache-nop.S Normal file
View file

@ -0,0 +1,50 @@
/*
* 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.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include "proc-macros.S"
ENTRY(nop_flush_icache_all)
mov pc, lr
ENDPROC(nop_flush_icache_all)
.globl nop_flush_kern_cache_all
.equ nop_flush_kern_cache_all, nop_flush_icache_all
.globl nop_flush_kern_cache_louis
.equ nop_flush_kern_cache_louis, nop_flush_icache_all
.globl nop_flush_user_cache_all
.equ nop_flush_user_cache_all, nop_flush_icache_all
.globl nop_flush_user_cache_range
.equ nop_flush_user_cache_range, nop_flush_icache_all
.globl nop_coherent_kern_range
.equ nop_coherent_kern_range, nop_flush_icache_all
ENTRY(nop_coherent_user_range)
mov r0, 0
mov pc, lr
ENDPROC(nop_coherent_user_range)
.globl nop_flush_kern_dcache_area
.equ nop_flush_kern_dcache_area, nop_flush_icache_all
.globl nop_dma_flush_range
.equ nop_dma_flush_range, nop_flush_icache_all
.globl nop_dma_map_area
.equ nop_dma_map_area, nop_flush_icache_all
.globl nop_dma_unmap_area
.equ nop_dma_unmap_area, nop_flush_icache_all
__INITDATA
@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
define_cache_functions nop

7
arch/arm/mm/nommu.c
View file

@ -20,12 +20,19 @@
void __init arm_mm_memblock_reserve(void)
{
#ifndef CONFIG_CPU_V7M
/*
* Register the exception vector page.
* some architectures which the DRAM is the exception vector to trap,
* alloc_page breaks with error, although it is not NULL, but "0."
*/
memblock_reserve(CONFIG_VECTORS_BASE, PAGE_SIZE);
#else /* ifndef CONFIG_CPU_V7M */
/*
* There is no dedicated vector page on V7-M. So nothing needs to be
* reserved here.
*/
#endif
}
void __init sanity_check_meminfo(void)

157
arch/arm/mm/proc-v7m.S Normal file
View file

@ -0,0 +1,157 @@
/*
* 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/v7m.h>
#include "proc-macros.S"
ENTRY(cpu_v7m_proc_init)
mov pc, lr
ENDPROC(cpu_v7m_proc_init)
ENTRY(cpu_v7m_proc_fin)
mov pc, 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)
mov pc, 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
mov pc, lr
ENDPROC(cpu_v7m_do_idle)
ENTRY(cpu_v7m_dcache_clean_area)
mov pc, lr
ENDPROC(cpu_v7m_dcache_clean_area)
/*
* There is no MMU, so here is nothing to do.
*/
ENTRY(cpu_v7m_switch_mm)
mov pc, 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)
mov pc, lr
ENDPROC(cpu_v7m_do_suspend)
ENTRY(cpu_v7m_do_resume)
mov pc, 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 run the kernel in this mode
adr r1, BSYM(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
mov r7, sp @ save SP
ldr sp, =__v7m_setup_stack_top
cpsie i
svc #0
1: cpsid i
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
mov lr, r6 @ restore LR
mov sp, r7 @ restore SP
@ 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]
mov pc, 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, #execinstr
/*
* 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
b __v7m_setup @ 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
__v7m_setup_stack:
.space 4 * 8 @ 8 registers
__v7m_setup_stack_top: