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authorRussell King <rmk+kernel@arm.linux.org.uk>2013-05-19 01:22:53 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-05-22 10:52:24 +0100
commitf150abe1012f2fc7d444d33d651db32435038c11 (patch)
treec42777a7237d97a32692ed41e174fbe92a32f69a
parent519fe2ecb755b875d9814cdda19778c2e88c6901 (diff)
parent6fae9cdafc92ae9958a3a45dd68205f72e3ad900 (diff)
Merge branch 'for-next' of git://git.pengutronix.de/git/ukl/linux into devel-stable
Pull ARM-v7M support from Uwe Kleine-König: "All but the last patch were in next since next-20130418 without issues. The last patch fixes a problem in combination with 8164f7a (ARM: 7680/1: Detect support for SDIV/UDIV from ISAR0 register) which triggers a WARN_ON without an implemented read_cpuid_ext. The branch merges fine into v3.10-rc1 and I'd be happy if you pulled it for 3.11-rc1. The only missing piece to be able to run a Cortex-M3 is the irqchip driver that will go in via Thomas Gleixner and platform specific stuff."
-rw-r--r--arch/arm/Kconfig4
-rw-r--r--arch/arm/Kconfig-nommu2
-rw-r--r--arch/arm/Makefile1
-rw-r--r--arch/arm/include/asm/assembler.h17
-rw-r--r--arch/arm/include/asm/cputype.h44
-rw-r--r--arch/arm/include/asm/glue-cache.h27
-rw-r--r--arch/arm/include/asm/glue-df.h8
-rw-r--r--arch/arm/include/asm/glue-proc.h9
-rw-r--r--arch/arm/include/asm/irqflags.h22
-rw-r--r--arch/arm/include/asm/ptrace.h4
-rw-r--r--arch/arm/include/asm/system_info.h1
-rw-r--r--arch/arm/include/asm/v7m.h44
-rw-r--r--arch/arm/include/uapi/asm/ptrace.h35
-rw-r--r--arch/arm/kernel/Makefile8
-rw-r--r--arch/arm/kernel/entry-common.S4
-rw-r--r--arch/arm/kernel/entry-header.S124
-rw-r--r--arch/arm/kernel/entry-v7m.S143
-rw-r--r--arch/arm/kernel/head-nommu.S10
-rw-r--r--arch/arm/kernel/setup.c17
-rw-r--r--arch/arm/kernel/traps.c8
-rw-r--r--arch/arm/mm/Kconfig21
-rw-r--r--arch/arm/mm/Makefile2
-rw-r--r--arch/arm/mm/cache-nop.S50
-rw-r--r--arch/arm/mm/nommu.c7
-rw-r--r--arch/arm/mm/proc-v7m.S157
25 files changed, 742 insertions, 27 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 49d993cee512..5543d36c2834 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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
@@ -1585,7 +1585,7 @@ 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
diff --git a/arch/arm/Kconfig-nommu b/arch/arm/Kconfig-nommu
index 2cef8e13f9f8..c859495da480 100644
--- a/arch/arm/Kconfig-nommu
+++ b/arch/arm/Kconfig-nommu
@@ -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.
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 1ba358ba16b8..3380c4f51757 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -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
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 05ee9eebad6b..a5fef710af32 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -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
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index 7652712d1d14..ec635ff32f49 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -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)
{
diff --git a/arch/arm/include/asm/glue-cache.h b/arch/arm/include/asm/glue-cache.h
index ea289e1435e7..c81adc08b3fb 100644
--- a/arch/arm/include/asm/glue-cache.h
+++ b/arch/arm/include/asm/glue-cache.h
@@ -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)
diff --git a/arch/arm/include/asm/glue-df.h b/arch/arm/include/asm/glue-df.h
index b6e9f2c108b5..6b70f1b46a6e 100644
--- a/arch/arm/include/asm/glue-df.h
+++ b/arch/arm/include/asm/glue-df.h
@@ -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
diff --git a/arch/arm/include/asm/glue-proc.h b/arch/arm/include/asm/glue-proc.h
index ac1dd54724b6..f2f39bcf7945 100644
--- a/arch/arm/include/asm/glue-proc.h
+++ b/arch/arm/include/asm/glue-proc.h
@@ -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)
diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
index 1e6cca55c750..3b763d6652a0 100644
--- a/arch/arm/include/asm/irqflags.h
+++ b/arch/arm/include/asm/irqflags.h
@@ -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 */
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 3d52ee1bfb31..04c99f36ff7f 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -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)
diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h
index dfd386d0c022..720ea0320a6d 100644
--- a/arch/arm/include/asm/system_info.h
+++ b/arch/arm/include/asm/system_info.h
@@ -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__
diff --git a/arch/arm/include/asm/v7m.h b/arch/arm/include/asm/v7m.h
new file mode 100644
index 000000000000..fa88d09fa3d9
--- /dev/null
+++ b/arch/arm/include/asm/v7m.h
@@ -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
diff --git a/arch/arm/include/uapi/asm/ptrace.h b/arch/arm/include/uapi/asm/ptrace.h
index 96ee0929790f..5af0ed1b825a 100644
--- a/arch/arm/include/uapi/asm/ptrace.h
+++ b/arch/arm/include/uapi/asm/ptrace.h
@@ -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
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5f3338eacad2..00d703c49f82 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -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
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index bc5bc0a97131..85a72b0809ca 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -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
/*
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 160f3376ba6d..de23a9beed13 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -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
diff --git a/arch/arm/kernel/entry-v7m.S b/arch/arm/kernel/entry-v7m.S
new file mode 100644
index 000000000000..e00621f1403f
--- /dev/null
+++ b/arch/arm/kernel/entry-v7m.S
@@ -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
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 6a2e09c952c7..8812ce88f7a1 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -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)?
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1522c7ae31b0..ea5cd6e3beb6 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -128,7 +128,9 @@ 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 +209,7 @@ static const char *proc_arch[] = {
"5TEJ",
"6TEJ",
"7",
- "?(11)",
+ "7M",
"?(12)",
"?(13)",
"?(14)",
@@ -216,6 +218,12 @@ 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 +256,7 @@ static int __get_cpu_architecture(void)
return cpu_arch;
}
+#endif
int __pure cpu_architecture(void)
{
@@ -293,7 +302,9 @@ 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 +403,7 @@ 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 +454,7 @@ 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];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 18b32e8e4497..486e12a0f26a 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -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
}
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 35955b54944c..9e8101ecd63e 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -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
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 9e51be96f635..ee558a01f390 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -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
diff --git a/arch/arm/mm/cache-nop.S b/arch/arm/mm/cache-nop.S
new file mode 100644
index 000000000000..8e12ddca0031
--- /dev/null
+++ b/arch/arm/mm/cache-nop.S
@@ -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
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index d51225f90ae2..dd3a6c670f08 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -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)
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
new file mode 100644
index 000000000000..0c93588fcb91
--- /dev/null
+++ b/arch/arm/mm/proc-v7m.S
@@ -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: