[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: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 302 insertions, 207 deletions

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index fbfc14a..e3770ed 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -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
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
new file mode 100644
index 0000000..a52da0d
--- /dev/null
+++ b/arch/arm/kernel/head-common.S
@@ -0,0 +1,217 @@
+/*
+ *  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}
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
new file mode 100644
index 0000000..b093ab8
--- /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"
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 571d6d5..d848f3a 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -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"