diff options
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 17 | ||||
| -rw-r--r-- | arch/arm/include/asm/cputype.h | 12 | ||||
| -rw-r--r-- | arch/arm/include/asm/glue-cache.h | 27 | ||||
| -rw-r--r-- | arch/arm/include/asm/glue-df.h | 8 | ||||
| -rw-r--r-- | arch/arm/include/asm/glue-proc.h | 9 | ||||
| -rw-r--r-- | arch/arm/include/asm/irqflags.h | 22 | ||||
| -rw-r--r-- | arch/arm/include/asm/ptrace.h | 4 | ||||
| -rw-r--r-- | arch/arm/include/asm/system_info.h | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/v7m.h | 44 | ||||
| -rw-r--r-- | arch/arm/include/uapi/asm/ptrace.h | 35 | ||||
| -rw-r--r-- | arch/arm/kernel/head-nommu.S | 10 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 17 | ||||
| -rw-r--r-- | arch/arm/kernel/traps.c | 8 | ||||
| -rw-r--r-- | arch/arm/mm/cache-nop.S | 50 | ||||
| -rw-r--r-- | arch/arm/mm/nommu.c | 7 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7m.S | 157 |
16 files changed, 407 insertions, 21 deletions
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..4eb94a3add3c 100644 --- a/arch/arm/include/asm/cputype.h +++ b/arch/arm/include/asm/cputype.h @@ -106,7 +106,17 @@ 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) + +#include <asm/io.h> +#include <asm/v7m.h> + +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 cca9f15704ed..65c9faf7a34a 100644 --- a/arch/arm/include/asm/glue-cache.h +++ b/arch/arm/include/asm/glue-cache.h @@ -125,10 +125,37 @@ # 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/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 1cc9e1796415..829124590e4c 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 */ @@ -375,6 +386,7 @@ static void __init feat_v6_fixup(void) */ void cpu_init(void) { +#ifndef CONFIG_CPU_V7M unsigned int cpu = smp_processor_id(); struct stack *stk = &stacks[cpu]; @@ -425,6 +437,7 @@ void 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 1c089119b2d7..ec64571462d2 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -819,6 +819,7 @@ 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[]; @@ -850,4 +851,11 @@ 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/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..000499cfceb3 --- /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|HWCAP_IDIVT + .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: |