diff options
Diffstat (limited to 'arch/arm/kernel/head-nommu.S')
-rw-r--r-- | arch/arm/kernel/head-nommu.S | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S new file mode 100644 index 00000000..278cfc14 --- /dev/null +++ b/arch/arm/kernel/head-nommu.S @@ -0,0 +1,98 @@ +/* + * linux/arch/arm/kernel/head-nommu.S + * + * Copyright (C) 1994-2002 Russell King + * Copyright (C) 2003-2006 Hyok S. Choi + * + * 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. + * + * Common kernel startup code (non-paged MM) + * + */ +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/assembler.h> +#include <asm/ptrace.h> +#include <asm/asm-offsets.h> +#include <asm/cp15.h> +#include <asm/thread_info.h> + +/* + * Kernel startup entry point. + * --------------------------- + * + * This is normally called from the decompressor code. The requirements + * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, + * r1 = machine nr. + * + * See linux/arch/arm/tools/mach-types for the complete list of machine + * numbers for r1. + * + */ + .arm + + __HEAD +ENTRY(stext) + + THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) + + 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 + mrc p15, 0, r9, c0, c0 @ get processor id +#endif + bl __lookup_processor_type @ r5=procinfo r9=cpuid + movs r10, r5 @ invalid processor (r5=0)? + beq __error_p @ yes, error 'p' + + adr lr, BSYM(__after_proc_init) @ return (PIC) address + ARM( add pc, r10, #PROCINFO_INITFUNC ) + THUMB( add r12, r10, #PROCINFO_INITFUNC ) + THUMB( mov pc, r12 ) +ENDPROC(stext) + +/* + * Set the Control Register and Read the process ID. + */ +__after_proc_init: +#ifdef CONFIG_CPU_CP15 + /* + * CP15 system control register value returned in r0 from + * the CPU init function. + */ +#ifdef CONFIG_ALIGNMENT_TRAP + orr r0, r0, #CR_A +#else + bic r0, r0, #CR_A +#endif +#ifdef CONFIG_CPU_DCACHE_DISABLE + bic r0, r0, #CR_C +#endif +#ifdef CONFIG_CPU_BPREDICT_DISABLE + bic r0, r0, #CR_Z +#endif +#ifdef CONFIG_CPU_ICACHE_DISABLE + bic r0, r0, #CR_I +#endif +#ifdef CONFIG_CPU_HIGH_VECTOR + orr r0, r0, #CR_V +#else + bic r0, r0, #CR_V +#endif + mcr p15, 0, r0, c1, c0, 0 @ write control reg +#endif /* CONFIG_CPU_CP15 */ + + b __mmap_switched @ clear the BSS and jump + @ to start_kernel +ENDPROC(__after_proc_init) + .ltorg + +#include "head-common.S" |