diff options
Diffstat (limited to 'arch/arm/kernel/head-nommu.S')
| -rw-r--r-- | arch/arm/kernel/head-nommu.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S new file mode 100644 index 00000000000..b093ab8738b --- /dev/null +++ b/arch/arm/kernel/head-nommu.S @@ -0,0 +1,83 @@ +/* + * 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) + * for 32-bit CPUs which has a process ID register(CP15). + * + */ +#include <linux/config.h> +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/assembler.h> +#include <asm/mach-types.h> +#include <asm/procinfo.h> +#include <asm/ptrace.h> +#include <asm/constants.h> +#include <asm/system.h> + +#define PROCINFO_INITFUNC 12 + +/* + * 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. + * + */ + __INIT + .type stext, %function +ENTRY(stext) + msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode + @ and irqs disabled + mrc p15, 0, r9, c0, c0 @ get processor id + bl __lookup_processor_type @ r5=procinfo r9=cpuid + movs r10, r5 @ invalid processor (r5=0)? + beq __error_p @ yes, error 'p' + bl __lookup_machine_type @ r5=machinfo + movs r8, r5 @ invalid machine (r5=0)? + beq __error_a @ yes, error 'a' + + ldr r13, __switch_data @ address to jump to after + @ the initialization is done + adr lr, __after_proc_init @ return (PIC) address + add pc, r10, #PROCINFO_INITFUNC + +/* + * Set the Control Register and Read the process ID. + */ + .type __after_proc_init, %function +__after_proc_init: + mrc p15, 0, r0, c1, c0, 0 @ read control reg +#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 + mcr p15, 0, r0, c1, c0, 0 @ write control reg + + mov pc, r13 @ clear the BSS and jump + @ to start_kernel + +#include "head-common.S" |