Commit 75d90832 authored by Hyok S. Choi's avatar Hyok S. Choi Committed by Russell King
Browse files

[ARM] nommu: start-up code 



This patch adds nommu version start-up code head-nommu.S.
The common part of the start-up codes is moved to head-common.S.

Signed-off-by: default avatarHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 10c2df65

arch/arm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ AFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float 
CHECKFLAGS	+= -D__arm__



#Default value

head-y		:= arch/arm/kernel/head.o arch/arm/kernel/init_task.o

head-y		:= arch/arm/kernel/head$(MMUEXT).o arch/arm/kernel/init_task.o

textofs-y	:= 0x00008000



 machine-$(CONFIG_ARCH_RPC)	   := rpc

arch/arm/kernel/head-common.S

0 → 100644
+217 −0
Original line number Diff line number Diff line 
/*

 *  linux/arch/arm/kernel/head-common.S

 *

 *  Copyright (C) 1994-2002 Russell King

 *  Copyright (c) 2003 ARM Limited

 *  All Rights Reserved

 *

 * 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.

 *

 */



	.type	__switch_data, %object

__switch_data:

	.long	__mmap_switched

	.long	__data_loc			@ r4

	.long	__data_start			@ r5

	.long	__bss_start			@ r6

	.long	_end				@ r7

	.long	processor_id			@ r4

	.long	__machine_arch_type		@ r5

	.long	cr_alignment			@ r6

	.long	init_thread_union + THREAD_START_SP @ sp



/*

 * The following fragment of code is executed with the MMU on in MMU mode,

 * and uses absolute addresses; this is not position independent.

 *

 *  r0  = cp#15 control register

 *  r1  = machine ID

 *  r9  = processor ID

 */

	.type	__mmap_switched, %function

__mmap_switched:

	adr	r3, __switch_data + 4



	ldmia	r3!, {r4, r5, r6, r7}

	cmp	r4, r5				@ Copy data segment if needed

1:	cmpne	r5, r6

	ldrne	fp, [r4], #4

	strne	fp, [r5], #4

	bne	1b



	mov	fp, #0				@ Clear BSS (and zero fp)

1:	cmp	r6, r7

	strcc	fp, [r6],#4

	bcc	1b



	ldmia	r3, {r4, r5, r6, sp}

	str	r9, [r4]			@ Save processor ID

	str	r1, [r5]			@ Save machine type

	bic	r4, r0, #CR_A			@ Clear 'A' bit

	stmia	r6, {r0, r4}			@ Save control register values

	b	start_kernel



/*

 * Exception handling.  Something went wrong and we can't proceed.  We

 * ought to tell the user, but since we don't have any guarantee that

 * we're even running on the right architecture, we do virtually nothing.

 *

 * If CONFIG_DEBUG_LL is set we try to print out something about the error

 * and hope for the best (useful if bootloader fails to pass a proper

 * machine ID for example).

 */



	.type	__error_p, %function

__error_p:

#ifdef CONFIG_DEBUG_LL

	adr	r0, str_p1

	bl	printascii

	b	__error

str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant.\n"

	.align

#endif



	.type	__error_a, %function

__error_a:

#ifdef CONFIG_DEBUG_LL

	mov	r4, r1				@ preserve machine ID

	adr	r0, str_a1

	bl	printascii

	mov	r0, r4

	bl	printhex8

	adr	r0, str_a2

	bl	printascii

	adr	r3, 3f

	ldmia	r3, {r4, r5, r6}		@ get machine desc list

	sub	r4, r3, r4			@ get offset between virt&phys

	add	r5, r5, r4			@ convert virt addresses to

	add	r6, r6, r4			@ physical address space

1:	ldr	r0, [r5, #MACHINFO_TYPE]	@ get machine type

	bl	printhex8

	mov	r0, #'\t'

	bl	printch

	ldr     r0, [r5, #MACHINFO_NAME]	@ get machine name

	add	r0, r0, r4

	bl	printascii

	mov	r0, #'\n'

	bl	printch

	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc

	cmp	r5, r6

	blo	1b

	adr	r0, str_a3

	bl	printascii

	b	__error

str_a1:	.asciz	"\nError: unrecognized/unsupported machine ID (r1 = 0x"

str_a2:	.asciz	").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"

str_a3:	.asciz	"\nPlease check your kernel config and/or bootloader.\n"

	.align

#endif



	.type	__error, %function

__error:

#ifdef CONFIG_ARCH_RPC

/*

 * Turn the screen red on a error - RiscPC only.

 */

	mov	r0, #0x02000000

	mov	r3, #0x11

	orr	r3, r3, r3, lsl #8

	orr	r3, r3, r3, lsl #16

	str	r3, [r0], #4

	str	r3, [r0], #4

	str	r3, [r0], #4

	str	r3, [r0], #4

#endif

1:	mov	r0, r0

	b	1b





/*

 * Read processor ID register (CP#15, CR0), and look up in the linker-built

 * supported processor list.  Note that we can't use the absolute addresses

 * for the __proc_info lists since we aren't running with the MMU on

 * (and therefore, we are not in the correct address space).  We have to

 * calculate the offset.

 *

 *	r9 = cpuid

 * Returns:

 *	r3, r4, r6 corrupted

 *	r5 = proc_info pointer in physical address space

 *	r9 = cpuid (preserved)

 */

	.type	__lookup_processor_type, %function

__lookup_processor_type:

	adr	r3, 3f

	ldmda	r3, {r5 - r7}

	sub	r3, r3, r7			@ get offset between virt&phys

	add	r5, r5, r3			@ convert virt addresses to

	add	r6, r6, r3			@ physical address space

1:	ldmia	r5, {r3, r4}			@ value, mask

	and	r4, r4, r9			@ mask wanted bits

	teq	r3, r4

	beq	2f

	add	r5, r5, #PROC_INFO_SZ		@ sizeof(proc_info_list)

	cmp	r5, r6

	blo	1b

	mov	r5, #0				@ unknown processor

2:	mov	pc, lr



/*

 * This provides a C-API version of the above function.

 */

ENTRY(lookup_processor_type)

	stmfd	sp!, {r4 - r7, r9, lr}

	mov	r9, r0

	bl	__lookup_processor_type

	mov	r0, r5

	ldmfd	sp!, {r4 - r7, r9, pc}



/*

 * Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for

 * more information about the __proc_info and __arch_info structures.

 */

	.long	__proc_info_begin

	.long	__proc_info_end

3:	.long	.

	.long	__arch_info_begin

	.long	__arch_info_end



/*

 * Lookup machine architecture in the linker-build list of architectures.

 * Note that we can't use the absolute addresses for the __arch_info

 * lists since we aren't running with the MMU on (and therefore, we are

 * not in the correct address space).  We have to calculate the offset.

 *

 *  r1 = machine architecture number

 * Returns:

 *  r3, r4, r6 corrupted

 *  r5 = mach_info pointer in physical address space

 */

	.type	__lookup_machine_type, %function

__lookup_machine_type:

	adr	r3, 3b

	ldmia	r3, {r4, r5, r6}

	sub	r3, r3, r4			@ get offset between virt&phys

	add	r5, r5, r3			@ convert virt addresses to

	add	r6, r6, r3			@ physical address space

1:	ldr	r3, [r5, #MACHINFO_TYPE]	@ get machine type

	teq	r3, r1				@ matches loader number?

	beq	2f				@ found

	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc

	cmp	r5, r6

	blo	1b

	mov	r5, #0				@ unknown machine

2:	mov	pc, lr



/*

 * This provides a C-API version of the above function.

 */

ENTRY(lookup_machine_type)

	stmfd	sp!, {r4 - r6, lr}

	mov	r1, r0

	bl	__lookup_machine_type

	mov	r0, r5

	ldmfd	sp!, {r4 - r6, pc}

arch/arm/kernel/head-nommu.S

0 → 100644
+83 −0
Original line number Diff line number Diff line 
/*

 *  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"

arch/arm/kernel/head.S

+1 −206
Original line number Diff line number Diff line
@@ -103,49 +103,6 @@ ENTRY(stext) 
	adr	lr, __enable_mmu		@ return (PIC) address

	add	pc, r10, #PROCINFO_INITFUNC



	.type	__switch_data, %object

__switch_data:

	.long	__mmap_switched

	.long	__data_loc			@ r4

	.long	__data_start			@ r5

	.long	__bss_start			@ r6

	.long	_end				@ r7

	.long	processor_id			@ r4

	.long	__machine_arch_type		@ r5

	.long	cr_alignment			@ r6

	.long	init_thread_union + THREAD_START_SP @ sp



/*

 * The following fragment of code is executed with the MMU on, and uses

 * absolute addresses; this is not position independent.

 *

 *  r0  = cp#15 control register

 *  r1  = machine ID

 *  r9  = processor ID

 */

	.type	__mmap_switched, %function

__mmap_switched:

	adr	r3, __switch_data + 4



	ldmia	r3!, {r4, r5, r6, r7}

	cmp	r4, r5				@ Copy data segment if needed

1:	cmpne	r5, r6

	ldrne	fp, [r4], #4

	strne	fp, [r5], #4

	bne	1b



	mov	fp, #0				@ Clear BSS (and zero fp)

1:	cmp	r6, r7

	strcc	fp, [r6],#4

	bcc	1b



	ldmia	r3, {r4, r5, r6, sp}

	str	r9, [r4]			@ Save processor ID

	str	r1, [r5]			@ Save machine type

	bic	r4, r0, #CR_A			@ Clear 'A' bit

	stmia	r6, {r0, r4}			@ Save control register values

	b	start_kernel



#if defined(CONFIG_SMP)

	.type   secondary_startup, #function

ENTRY(secondary_startup)
@@ -368,166 +325,4 @@ __create_page_tables: 
	mov	pc, lr

	.ltorg







/*

 * Exception handling.  Something went wrong and we can't proceed.  We

 * ought to tell the user, but since we don't have any guarantee that

 * we're even running on the right architecture, we do virtually nothing.

 *

 * If CONFIG_DEBUG_LL is set we try to print out something about the error

 * and hope for the best (useful if bootloader fails to pass a proper

 * machine ID for example).

 */



	.type	__error_p, %function

__error_p:

#ifdef CONFIG_DEBUG_LL

	adr	r0, str_p1

	bl	printascii

	b	__error

str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant.\n"

	.align

#endif



	.type	__error_a, %function

__error_a:

#ifdef CONFIG_DEBUG_LL

	mov	r4, r1				@ preserve machine ID

	adr	r0, str_a1

	bl	printascii

	mov	r0, r4

	bl	printhex8

	adr	r0, str_a2

	bl	printascii

	adr	r3, 3f

	ldmia	r3, {r4, r5, r6}		@ get machine desc list

	sub	r4, r3, r4			@ get offset between virt&phys

	add	r5, r5, r4			@ convert virt addresses to

	add	r6, r6, r4			@ physical address space

1:	ldr	r0, [r5, #MACHINFO_TYPE]	@ get machine type

	bl	printhex8

	mov	r0, #'\t'

	bl	printch

	ldr     r0, [r5, #MACHINFO_NAME]	@ get machine name

	add	r0, r0, r4

	bl	printascii

	mov	r0, #'\n'

	bl	printch

	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc

	cmp	r5, r6

	blo	1b

	adr	r0, str_a3

	bl	printascii

	b	__error

str_a1:	.asciz	"\nError: unrecognized/unsupported machine ID (r1 = 0x"

str_a2:	.asciz	").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"

str_a3:	.asciz	"\nPlease check your kernel config and/or bootloader.\n"

	.align

#endif



	.type	__error, %function

__error:

#ifdef CONFIG_ARCH_RPC

/*

 * Turn the screen red on a error - RiscPC only.

 */

	mov	r0, #0x02000000

	mov	r3, #0x11

	orr	r3, r3, r3, lsl #8

	orr	r3, r3, r3, lsl #16

	str	r3, [r0], #4

	str	r3, [r0], #4

	str	r3, [r0], #4

	str	r3, [r0], #4

#endif

1:	mov	r0, r0

	b	1b





/*

 * Read processor ID register (CP#15, CR0), and look up in the linker-built

 * supported processor list.  Note that we can't use the absolute addresses

 * for the __proc_info lists since we aren't running with the MMU on

 * (and therefore, we are not in the correct address space).  We have to

 * calculate the offset.

 *

 *	r9 = cpuid

 * Returns:

 *	r3, r4, r6 corrupted

 *	r5 = proc_info pointer in physical address space

 *	r9 = cpuid (preserved)

 */

	.type	__lookup_processor_type, %function

__lookup_processor_type:

	adr	r3, 3f

	ldmda	r3, {r5 - r7}

	sub	r3, r3, r7			@ get offset between virt&phys

	add	r5, r5, r3			@ convert virt addresses to

	add	r6, r6, r3			@ physical address space

1:	ldmia	r5, {r3, r4}			@ value, mask

	and	r4, r4, r9			@ mask wanted bits

	teq	r3, r4

	beq	2f

	add	r5, r5, #PROC_INFO_SZ		@ sizeof(proc_info_list)

	cmp	r5, r6

	blo	1b

	mov	r5, #0				@ unknown processor

2:	mov	pc, lr



/*

 * This provides a C-API version of the above function.

 */

ENTRY(lookup_processor_type)

	stmfd	sp!, {r4 - r7, r9, lr}

	mov	r9, r0

	bl	__lookup_processor_type

	mov	r0, r5

	ldmfd	sp!, {r4 - r7, r9, pc}



/*

 * Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for

 * more information about the __proc_info and __arch_info structures.

 */

	.long	__proc_info_begin

	.long	__proc_info_end

3:	.long	.

	.long	__arch_info_begin

	.long	__arch_info_end



/*

 * Lookup machine architecture in the linker-build list of architectures.

 * Note that we can't use the absolute addresses for the __arch_info

 * lists since we aren't running with the MMU on (and therefore, we are

 * not in the correct address space).  We have to calculate the offset.

 *

 *  r1 = machine architecture number

 * Returns:

 *  r3, r4, r6 corrupted

 *  r5 = mach_info pointer in physical address space

 */

	.type	__lookup_machine_type, %function

__lookup_machine_type:

	adr	r3, 3b

	ldmia	r3, {r4, r5, r6}

	sub	r3, r3, r4			@ get offset between virt&phys

	add	r5, r5, r3			@ convert virt addresses to

	add	r6, r6, r3			@ physical address space

1:	ldr	r3, [r5, #MACHINFO_TYPE]	@ get machine type

	teq	r3, r1				@ matches loader number?

	beq	2f				@ found

	add	r5, r5, #SIZEOF_MACHINE_DESC	@ next machine_desc

	cmp	r5, r6

	blo	1b

	mov	r5, #0				@ unknown machine

2:	mov	pc, lr



/*

 * This provides a C-API version of the above function.

 */

ENTRY(lookup_machine_type)

	stmfd	sp!, {r4 - r6, lr}

	mov	r1, r0

	bl	__lookup_machine_type

	mov	r0, r5

	ldmfd	sp!, {r4 - r6, pc}
 
#include "head-common.S"

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