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1 | /* |
2 | * linux/arch/arm/kernel/head-nommu.S | |
3 | * | |
4 | * Copyright (C) 1994-2002 Russell King | |
5 | * Copyright (C) 2003-2006 Hyok S. Choi | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * Common kernel startup code (non-paged MM) | |
12 | * for 32-bit CPUs which has a process ID register(CP15). | |
13 | * | |
14 | */ | |
15 | #include <linux/config.h> | |
16 | #include <linux/linkage.h> | |
17 | #include <linux/init.h> | |
18 | ||
19 | #include <asm/assembler.h> | |
20 | #include <asm/mach-types.h> | |
21 | #include <asm/procinfo.h> | |
22 | #include <asm/ptrace.h> | |
3b920cef | 23 | #include <asm/thread_info.h> |
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24 | #include <asm/system.h> |
25 | ||
26 | #define PROCINFO_INITFUNC 12 | |
3b920cef | 27 | #define MACHINFO_TYPE 0 |
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28 | |
29 | /* | |
30 | * Kernel startup entry point. | |
31 | * --------------------------- | |
32 | * | |
33 | * This is normally called from the decompressor code. The requirements | |
34 | * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, | |
35 | * r1 = machine nr. | |
36 | * | |
37 | * See linux/arch/arm/tools/mach-types for the complete list of machine | |
38 | * numbers for r1. | |
39 | * | |
40 | */ | |
41 | __INIT | |
42 | .type stext, %function | |
43 | ENTRY(stext) | |
44 | msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode | |
45 | @ and irqs disabled | |
46 | mrc p15, 0, r9, c0, c0 @ get processor id | |
47 | bl __lookup_processor_type @ r5=procinfo r9=cpuid | |
48 | movs r10, r5 @ invalid processor (r5=0)? | |
49 | beq __error_p @ yes, error 'p' | |
50 | bl __lookup_machine_type @ r5=machinfo | |
51 | movs r8, r5 @ invalid machine (r5=0)? | |
52 | beq __error_a @ yes, error 'a' | |
53 | ||
54 | ldr r13, __switch_data @ address to jump to after | |
55 | @ the initialization is done | |
56 | adr lr, __after_proc_init @ return (PIC) address | |
57 | add pc, r10, #PROCINFO_INITFUNC | |
58 | ||
59 | /* | |
60 | * Set the Control Register and Read the process ID. | |
61 | */ | |
62 | .type __after_proc_init, %function | |
63 | __after_proc_init: | |
64 | mrc p15, 0, r0, c1, c0, 0 @ read control reg | |
65 | #ifdef CONFIG_ALIGNMENT_TRAP | |
66 | orr r0, r0, #CR_A | |
67 | #else | |
68 | bic r0, r0, #CR_A | |
69 | #endif | |
70 | #ifdef CONFIG_CPU_DCACHE_DISABLE | |
71 | bic r0, r0, #CR_C | |
72 | #endif | |
73 | #ifdef CONFIG_CPU_BPREDICT_DISABLE | |
74 | bic r0, r0, #CR_Z | |
75 | #endif | |
76 | #ifdef CONFIG_CPU_ICACHE_DISABLE | |
77 | bic r0, r0, #CR_I | |
78 | #endif | |
79 | mcr p15, 0, r0, c1, c0, 0 @ write control reg | |
80 | ||
81 | mov pc, r13 @ clear the BSS and jump | |
82 | @ to start_kernel | |
3b920cef | 83 | .ltorg |
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84 | |
85 | #include "head-common.S" |