From patchwork Fri Aug 3 10:10:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1270261 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 0A28ADF25A for ; Fri, 3 Aug 2012 10:14:28 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SxEqd-0005ML-CZ; Fri, 03 Aug 2012 10:11:11 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SxEqM-0005FI-CL for linux-arm-kernel@lists.infradead.org; Fri, 03 Aug 2012 10:10:58 +0000 Received: from dude.hi.pengutronix.de ([2001:6f8:1178:2:21e:67ff:fe11:9c5c]) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1SxEpn-0002Pi-QL; Fri, 03 Aug 2012 12:10:19 +0200 Received: from ukl by dude.hi.pengutronix.de with local (Exim 4.80) (envelope-from ) id 1SxEpn-0001Rb-NX; Fri, 03 Aug 2012 12:10:19 +0200 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= To: Russell King Subject: [PATCH v6 2/3] Cortex-M3: Add base support for Cortex-M3 Date: Fri, 3 Aug 2012 12:10:13 +0200 Message-Id: <1343988614-5508-3-git-send-email-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1343988614-5508-1-git-send-email-u.kleine-koenig@pengutronix.de> References: <1343988614-5508-1-git-send-email-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:6f8:1178:2:21e:67ff:fe11:9c5c X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Arnd Bergmann , Nicolas Pitre , Catalin Marinas , Will Deacon , kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Catalin Marinas This patch adds the base support for the Cortex-M3 processor (ARMv7-M architecture). It consists of the corresponding arch/arm/mm/ files and various #ifdef's around the kernel. Exception handling is implemented by a subsequent patch. [ukleinek: squash in some changes originating from commit b5717ba (Cortex-M3: Add support for the Microcontroller Prototyping System) from the v2.6.33-arm1 patch stack, port to post 3.4, drop zImage support, drop reorganisation of pt_regs, assert CONFIG_V7M doesn't leak into installed headers and a few cosmetic changes] Signed-off-by: Catalin Marinas Signed-off-by: Uwe Kleine-König --- Changes since v4, id:1333573807-23709-2-git-send-email-u.kleine-koenig@pengutronix.de - simplify irq enable/disable ops as suggested by Russell - don't leak kernel config symbols into userspace headers and add some comments --- arch/arm/include/asm/assembler.h | 13 ++- arch/arm/include/asm/cputype.h | 3 + arch/arm/include/asm/glue-cache.h | 24 ++++++ arch/arm/include/asm/glue-df.h | 8 ++ arch/arm/include/asm/glue-proc.h | 9 ++ arch/arm/include/asm/irqflags.h | 22 +++-- arch/arm/include/asm/processor.h | 7 ++ arch/arm/include/asm/ptrace.h | 44 ++++++++-- arch/arm/include/asm/system_info.h | 1 + arch/arm/kernel/asm-offsets.c | 3 + arch/arm/kernel/head-nommu.S | 9 +- arch/arm/kernel/setup.c | 13 ++- arch/arm/kernel/traps.c | 2 + arch/arm/mm/nommu.c | 2 + arch/arm/mm/proc-v7m.S | 161 ++++++++++++++++++++++++++++++++++++ 15 files changed, 302 insertions(+), 19 deletions(-) create mode 100644 arch/arm/mm/proc-v7m.S diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 03fb936..705d108 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -135,7 +135,11 @@ * 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 @@ -149,7 +153,11 @@ * 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 @@ -228,7 +236,10 @@ #endif .endm -#ifdef CONFIG_THUMB2_KERNEL +#if defined(CONFIG_CPU_V7M) + .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 cb47d28..5bd8cb6 100644 --- a/arch/arm/include/asm/cputype.h +++ b/arch/arm/include/asm/cputype.h @@ -46,6 +46,9 @@ extern unsigned int processor_id; : "cc"); \ __val; \ }) +#elif defined(CONFIG_CPU_V7M) +#define read_cpuid(reg) (*(unsigned int *)0xe000ed00) +#define read_cpuid_ext(reg) 0 #else #define read_cpuid(reg) (processor_id) #define read_cpuid_ext(reg) 0 diff --git a/arch/arm/include/asm/glue-cache.h b/arch/arm/include/asm/glue-cache.h index 7e30874..a02fd01 100644 --- a/arch/arm/include/asm/glue-cache.h +++ b/arch/arm/include/asm/glue-cache.h @@ -125,10 +125,34 @@ //# endif #endif +#if defined(CONFIG_CPU_V7M) +# ifdef _CACHE +# error "Multi-cache not supported on ARMv7-M" +# else +# define _CACHE nop +# endif +#endif + #if !defined(_CACHE) && !defined(MULTI_CACHE) #error Unknown cache maintenance model #endif +#ifndef __ASSEMBLER__ +static inline void nop_flush_icache_all(void) { } +static inline void nop_flush_kern_cache_all(void) { } +static inline void nop_flush_user_cache_all(void) { } +static inline void nop_flush_user_cache_range(unsigned long a, unsigned long b, unsigned int c) { } + +static inline void nop_coherent_kern_range(unsigned long a, unsigned long b) { } +static inline int nop_coherent_user_range(unsigned long a, unsigned long b) { return 0; } +static inline void nop_flush_kern_dcache_area(void *a, size_t s) { } + +static inline void nop_dma_flush_range(const void *a, const void *b) { } + +static inline void nop_dma_map_area(const void *s, size_t l, int f) { } +static 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 8cacbcd..1f2339c 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 ac1dd54..f2f39bc 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 1e6cca5..3b763d6 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/processor.h b/arch/arm/include/asm/processor.h index 99afa74..dc82aa0 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -49,7 +49,14 @@ struct thread_struct { #ifdef CONFIG_MMU #define nommu_start_thread(regs) do { } while (0) #else +#ifndef CONFIG_CPU_V7M #define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data +#else +#define nommu_start_thread(regs) do { \ + regs->ARM_r10 = current->mm->start_data; \ + regs->ARM_EXC_RET = 0xfffffffdL; \ +} while (0) +#endif #endif #define start_thread(regs,pc,sp) \ diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 355ece5..090fea7 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -34,27 +34,46 @@ /* * 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 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 @@ -106,7 +125,11 @@ struct pt_regs { }; #else /* __KERNEL__ */ struct pt_regs { +#ifdef CONFIG_CPU_V7M + unsigned long uregs[20]; +#else unsigned long uregs[18]; +#endif }; #endif /* __KERNEL__ */ @@ -128,6 +151,7 @@ struct pt_regs { #define ARM_r1 uregs[1] #define ARM_r0 uregs[0] #define ARM_ORIG_r0 uregs[17] +#define ARM_EXC_RET uregs[18] /* * The size of the user-visible VFP state as seen by PTRACE_GET/SETVFPREGS @@ -165,6 +189,7 @@ 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; /* @@ -187,6 +212,9 @@ 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 dfd386d..720ea03 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/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 1429d89..6f6b5b6 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -91,6 +91,9 @@ int main(void) DEFINE(S_PC, offsetof(struct pt_regs, ARM_pc)); DEFINE(S_PSR, offsetof(struct pt_regs, ARM_cpsr)); DEFINE(S_OLD_R0, offsetof(struct pt_regs, ARM_ORIG_r0)); +#ifdef CONFIG_CPU_V7M + DEFINE(S_EXC_RET, offsetof(struct pt_regs, ARM_EXC_RET)); +#endif DEFINE(S_FRAME_SIZE, sizeof(struct pt_regs)); BLANK(); #ifdef CONFIG_CACHE_L2X0 diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index 278cfc1..c391c05 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -44,10 +44,13 @@ 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, =0xe000ed00 @ CPUID register address + ldr r9, [r9] +#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 e15d83b..e80ccab 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -135,7 +135,9 @@ 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); @@ -215,7 +217,7 @@ static const char *proc_arch[] = { "5TEJ", "6TEJ", "7", - "?(11)", + "7M", "?(12)", "?(13)", "?(14)", @@ -224,6 +226,12 @@ 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; @@ -256,6 +264,7 @@ static int __get_cpu_architecture(void) return cpu_arch; } +#endif int __pure cpu_architecture(void) { @@ -383,6 +392,7 @@ 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]; @@ -427,6 +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 3647170..7c62282 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -792,6 +792,7 @@ 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[]; @@ -825,4 +826,5 @@ void __init early_trap_init(void *vectors_base) flush_icache_range(vectors, vectors + PAGE_SIZE); modify_domain(DOMAIN_USER, DOMAIN_CLIENT); +#endif } diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c index d51225f..4bc8ae5 100644 --- a/arch/arm/mm/nommu.c +++ b/arch/arm/mm/nommu.c @@ -20,12 +20,14 @@ 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); +#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 0000000..2b8eb97 --- /dev/null +++ b/arch/arm/mm/proc-v7m.S @@ -0,0 +1,161 @@ +/* + * 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 +#include + +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) + +cpu_v7m_name: + .ascii "ARMv7-M Processor" + .align + + .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, =0xe000ed08 @ vector table base address + ldr r12, =vector_table + str r12, [r0] + + @ Lower the priority of the SVC and PendSV exceptions + ldr r0, =0xe000ed1c + mov r5, #0x80000000 + str r5, [r0] @ set SVC priority + ldr r0, =0xe000ed20 + mov r5, #0x00800000 + str r5, [r0] @ set PendSV priority + + @ SVC to run the kernel in this mode + adr r0, BSYM(1f) + ldr r5, [r12, #11 * 4] @ read the SVC vector entry + str r0, [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 r0, #1 + msr control, r0 @ Thread mode has unpriviledged access + + @ Configure the System Control Register + ldr r0, =0xe000ed14 @ system control register + ldr r12, [r0] + orr r12, #1 << 9 @ STKALIGN + str r12, [r0] + mov pc, lr +ENDPROC(__v7m_setup) + + .align 2 + .type v7m_processor_functions, #object +ENTRY(v7m_processor_functions) + .word nommu_early_abort + .word cpu_v7m_proc_init + .word cpu_v7m_proc_fin + .word cpu_v7m_reset + .word cpu_v7m_do_idle + .word cpu_v7m_dcache_clean_area + .word cpu_v7m_switch_mm + .word 0 @ cpu_v7m_set_pte_ext + .word legacy_pabort + .size v7m_processor_functions, . - v7m_processor_functions + + .type cpu_arch_name, #object +cpu_arch_name: + .asciz "armv7m" + .size cpu_arch_name, . - cpu_arch_name + + .type cpu_elf_name, #object +cpu_elf_name: + .asciz "v7m" + .size cpu_elf_name, . - cpu_elf_name + .align + + .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_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP + .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 0 @ proc_info_list.cache + .size __v7m_proc_info, . - __v7m_proc_info + +__v7m_setup_stack: + .space 4 * 8 @ 8 registers +__v7m_setup_stack_top: