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Hyok S. Choi75d90832006-03-27 14:58:25 +01001/*
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 */
Hyok S. Choi75d90832006-03-27 14:58:25 +010015#include <linux/linkage.h>
16#include <linux/init.h>
17
18#include <asm/assembler.h>
19#include <asm/mach-types.h>
20#include <asm/procinfo.h>
21#include <asm/ptrace.h>
Uwe Zeisberger2eb9d312006-05-05 15:11:14 +010022#include <asm/asm-offsets.h>
Hyok S. Choi3b920ce2006-04-24 09:45:35 +010023#include <asm/thread_info.h>
Hyok S. Choi75d90832006-03-27 14:58:25 +010024#include <asm/system.h>
25
Hyok S. Choi75d90832006-03-27 14:58:25 +010026/*
27 * Kernel startup entry point.
28 * ---------------------------
29 *
30 * This is normally called from the decompressor code. The requirements
31 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
32 * r1 = machine nr.
33 *
34 * See linux/arch/arm/tools/mach-types for the complete list of machine
35 * numbers for r1.
36 *
37 */
38 __INIT
39 .type stext, %function
40ENTRY(stext)
Russell King801194e2006-06-25 12:01:48 +010041 msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode
Hyok S. Choi75d90832006-03-27 14:58:25 +010042 @ and irqs disabled
43 mrc p15, 0, r9, c0, c0 @ get processor id
44 bl __lookup_processor_type @ r5=procinfo r9=cpuid
45 movs r10, r5 @ invalid processor (r5=0)?
46 beq __error_p @ yes, error 'p'
47 bl __lookup_machine_type @ r5=machinfo
48 movs r8, r5 @ invalid machine (r5=0)?
49 beq __error_a @ yes, error 'a'
50
51 ldr r13, __switch_data @ address to jump to after
52 @ the initialization is done
53 adr lr, __after_proc_init @ return (PIC) address
54 add pc, r10, #PROCINFO_INITFUNC
55
56/*
57 * Set the Control Register and Read the process ID.
58 */
59 .type __after_proc_init, %function
60__after_proc_init:
61 mrc p15, 0, r0, c1, c0, 0 @ read control reg
62#ifdef CONFIG_ALIGNMENT_TRAP
63 orr r0, r0, #CR_A
64#else
65 bic r0, r0, #CR_A
66#endif
67#ifdef CONFIG_CPU_DCACHE_DISABLE
68 bic r0, r0, #CR_C
69#endif
70#ifdef CONFIG_CPU_BPREDICT_DISABLE
71 bic r0, r0, #CR_Z
72#endif
73#ifdef CONFIG_CPU_ICACHE_DISABLE
74 bic r0, r0, #CR_I
75#endif
76 mcr p15, 0, r0, c1, c0, 0 @ write control reg
77
78 mov pc, r13 @ clear the BSS and jump
79 @ to start_kernel
Hyok S. Choi3b920ce2006-04-24 09:45:35 +010080 .ltorg
Hyok S. Choi75d90832006-03-27 14:58:25 +010081
82#include "head-common.S"