[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / head-common.S

/*
 *  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.
 *
 */

#define ATAG_CORE 0x54410001
#define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2)
#define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2)

/*
 * 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).
 */
	__HEAD
__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, __lookup_machine_type_data
	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
ENDPROC(__error_a)

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
#else
	b	__error
#endif

/*
 * 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
 */
__lookup_machine_type:
	adr	r3, __lookup_machine_type_data
	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
ENDPROC(__lookup_machine_type)

/*
 * Look in arch/arm/kernel/arch.[ch] for information about the
 * __arch_info structures.
 */
	.align	2
	.type	__lookup_machine_type_data, %object
__lookup_machine_type_data:
	.long	.
	.long	__arch_info_begin
	.long	__arch_info_end
	.size	__lookup_machine_type_data, . - __lookup_machine_type_data

/* Determine validity of the r2 atags pointer.  The heuristic requires
 * that the pointer be aligned, in the first 16k of physical RAM and
 * that the ATAG_CORE marker is first and present.  Future revisions
 * of this function may be more lenient with the physical address and
 * may also be able to move the ATAGS block if necessary.
 *
 * r8  = machinfo
 *
 * Returns:
 *  r2 either valid atags pointer, or zero
 *  r5, r6 corrupted
 */
__vet_atags:
	tst	r2, #0x3			@ aligned?
	bne	1f

	ldr	r5, [r2, #0]			@ is first tag ATAG_CORE?
	cmp	r5, #ATAG_CORE_SIZE
	cmpne	r5, #ATAG_CORE_SIZE_EMPTY
	bne	1f
	ldr	r5, [r2, #4]
	ldr	r6, =ATAG_CORE
	cmp	r5, r6
	bne	1f

	mov	pc, lr				@ atag pointer is ok

1:	mov	r2, #0
	mov	pc, lr
ENDPROC(__vet_atags)

/*
 * 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
 *  r2  = atags pointer
 *  r9  = processor ID
 */
	__INIT
__mmap_switched:
	adr	r3, __mmap_switched_data

	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

 ARM(	ldmia	r3, {r4, r5, r6, r7, sp})
 THUMB(	ldmia	r3, {r4, r5, r6, r7}	)
 THUMB(	ldr	sp, [r3, #16]		)
	str	r9, [r4]			@ Save processor ID
	str	r1, [r5]			@ Save machine type
	str	r2, [r6]			@ Save atags pointer
	bic	r4, r0, #CR_A			@ Clear 'A' bit
	stmia	r7, {r0, r4}			@ Save control register values
	b	start_kernel
ENDPROC(__mmap_switched)

	.align	2
	.type	__mmap_switched_data, %object
__mmap_switched_data:
	.long	__data_loc			@ r4
	.long	_sdata				@ r5
	.long	__bss_start			@ r6
	.long	_end				@ r7
	.long	processor_id			@ r4
	.long	__machine_arch_type		@ r5
	.long	__atags_pointer			@ r6
	.long	cr_alignment			@ r7
	.long	init_thread_union + THREAD_START_SP @ sp
	.size	__mmap_switched_data, . - __mmap_switched_data

/*
 * This provides a C-API version of __lookup_machine_type
 */
ENTRY(lookup_machine_type)
	stmfd	sp!, {r4 - r6, lr}
	mov	r1, r0
	bl	__lookup_machine_type
	mov	r0, r5
	ldmfd	sp!, {r4 - r6, pc}
ENDPROC(lookup_machine_type)

/*
 * This provides a C-API version of __lookup_processor_type
 */
ENTRY(lookup_processor_type)
	stmfd	sp!, {r4 - r6, r9, lr}
	mov	r9, r0
	bl	__lookup_processor_type
	mov	r0, r5
	ldmfd	sp!, {r4 - r6, r9, pc}
ENDPROC(lookup_processor_type)

/*
 * 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)
 */
	__CPUINIT
__lookup_processor_type:
	adr	r3, __lookup_processor_type_data
	ldmia	r3, {r4 - 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:	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
ENDPROC(__lookup_processor_type)

/*
 * Look in <asm/procinfo.h> for information about the __proc_info structure.
 */
	.align	2
	.type	__lookup_processor_type_data, %object
__lookup_processor_type_data:
	.long	.
	.long	__proc_info_begin
	.long	__proc_info_end
	.size	__lookup_processor_type_data, . - __lookup_processor_type_data

__error_p:
#ifdef CONFIG_DEBUG_LL
	adr	r0, str_p1
	bl	printascii
	mov	r0, r9
	bl	printhex8
	adr	r0, str_p2
	bl	printascii
	b	__error
str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant (0x"
str_p2:	.asciz	").\n"
	.align
#endif
ENDPROC(__error_p)

__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
ENDPROC(__error)
Commit	Line	Data
75d90832 HC	1	/*
	2	* linux/arch/arm/kernel/head-common.S
	3	*
	4	* Copyright (C) 1994-2002 Russell King
	5	* Copyright (c) 2003 ARM Limited
	6	* All Rights Reserved
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
9c4c9f38 GU	14	#define ATAG_CORE 0x54410001
9c4c9f38 GU	15	#define ATAG_CORE_SIZE ((24 + 34) >> 2)
31abdb74	16	#define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2)
9c4c9f38	17
75d90832 HC	18	/*
	19	* Exception handling. Something went wrong and we can't proceed. We
	20	* ought to tell the user, but since we don't have any guarantee that
	21	* we're even running on the right architecture, we do virtually nothing.
	22	*
	23	* If CONFIG_DEBUG_LL is set we try to print out something about the error
	24	* and hope for the best (useful if bootloader fails to pass a proper
	25	* machine ID for example).
	26	*/
80924ac5	27	__HEAD
75d90832 HC	28	__error_a:
	29	#ifdef CONFIG_DEBUG_LL
	30	mov r4, r1 @ preserve machine ID
	31	adr r0, str_a1
	32	bl printascii
	33	mov r0, r4
	34	bl printhex8
	35	adr r0, str_a2
	36	bl printascii
80924ac5	37	adr r3, __lookup_machine_type_data
75d90832 HC	38	ldmia r3, {r4, r5, r6} @ get machine desc list
	39	sub r4, r3, r4 @ get offset between virt&phys
	40	add r5, r5, r4 @ convert virt addresses to
	41	add r6, r6, r4 @ physical address space
	42	1: ldr r0, [r5, #MACHINFO_TYPE] @ get machine type
	43	bl printhex8
	44	mov r0, #'\t'
	45	bl printch
	46	ldr r0, [r5, #MACHINFO_NAME] @ get machine name
	47	add r0, r0, r4
	48	bl printascii
	49	mov r0, #'\n'
	50	bl printch
	51	add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
	52	cmp r5, r6
	53	blo 1b
	54	adr r0, str_a3
	55	bl printascii
	56	b __error
93ed3970 CM	57	ENDPROC(__error_a)
93ed3970 CM	58
75d90832 HC	59	str_a1: .asciz "\nError: unrecognized/unsupported machine ID (r1 = 0x"
	60	str_a2: .asciz ").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"
	61	str_a3: .asciz "\nPlease check your kernel config and/or bootloader.\n"
	62	.align
cb4d3eae RK	63	#else
cb4d3eae RK	64	b __error
75d90832 HC	65	#endif
75d90832 HC	66
75d90832 HC	67	/*
	68	* Lookup machine architecture in the linker-build list of architectures.
	69	* Note that we can't use the absolute addresses for the __arch_info
	70	* lists since we aren't running with the MMU on (and therefore, we are
	71	* not in the correct address space). We have to calculate the offset.
	72	*
	73	* r1 = machine architecture number
	74	* Returns:
	75	* r3, r4, r6 corrupted
	76	* r5 = mach_info pointer in physical address space
	77	*/
75d90832	78	__lookup_machine_type:
80924ac5	79	adr r3, __lookup_machine_type_data
75d90832 HC	80	ldmia r3, {r4, r5, r6}
	81	sub r3, r3, r4 @ get offset between virt&phys
	82	add r5, r5, r3 @ convert virt addresses to
	83	add r6, r6, r3 @ physical address space
	84	1: ldr r3, [r5, #MACHINFO_TYPE] @ get machine type
	85	teq r3, r1 @ matches loader number?
	86	beq 2f @ found
	87	add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
	88	cmp r5, r6
	89	blo 1b
	90	mov r5, #0 @ unknown machine
	91	2: mov pc, lr
93ed3970	92	ENDPROC(__lookup_machine_type)
75d90832 HC	93
75d90832 HC	94	/*
80924ac5 RK	95	* Look in arch/arm/kernel/arch.[ch] for information about the
80924ac5 RK	96	* __arch_info structures.
75d90832	97	*/
80924ac5 RK	98	.align 2
	99	.type __lookup_machine_type_data, %object
	100	__lookup_machine_type_data:
	101	.long .
	102	.long __arch_info_begin
	103	.long __arch_info_end
	104	.size __lookup_machine_type_data, . - __lookup_machine_type_data
9d20fdd5 BG	105
	106	/* Determine validity of the r2 atags pointer. The heuristic requires
	107	* that the pointer be aligned, in the first 16k of physical RAM and
	108	* that the ATAG_CORE marker is first and present. Future revisions
	109	* of this function may be more lenient with the physical address and
	110	* may also be able to move the ATAGS block if necessary.
	111	*
	112	* r8 = machinfo
	113	*
	114	* Returns:
	115	* r2 either valid atags pointer, or zero
	116	* r5, r6 corrupted
	117	*/
9d20fdd5 BG	118	__vet_atags:
	119	tst r2, #0x3 @ aligned?
	120	bne 1f
	121
	122	ldr r5, [r2, #0] @ is first tag ATAG_CORE?
31abdb74 DB	123	cmp r5, #ATAG_CORE_SIZE
31abdb74 DB	124	cmpne r5, #ATAG_CORE_SIZE_EMPTY
9d20fdd5 BG	125	bne 1f
	126	ldr r5, [r2, #4]
	127	ldr r6, =ATAG_CORE
	128	cmp r5, r6
	129	bne 1f
	130
	131	mov pc, lr @ atag pointer is ok
	132
	133	1: mov r2, #0
	134	mov pc, lr
93ed3970	135	ENDPROC(__vet_atags)
5085f3ff	136
17bb5e2c RK	137	/*
	138	* The following fragment of code is executed with the MMU on in MMU mode,
	139	* and uses absolute addresses; this is not position independent.
	140	*
	141	* r0 = cp#15 control register
	142	* r1 = machine ID
	143	* r2 = atags pointer
	144	* r9 = processor ID
	145	*/
	146	__INIT
	147	__mmap_switched:
	148	adr r3, __mmap_switched_data
	149
	150	ldmia r3!, {r4, r5, r6, r7}
	151	cmp r4, r5 @ Copy data segment if needed
	152	1: cmpne r5, r6
	153	ldrne fp, [r4], #4
	154	strne fp, [r5], #4
	155	bne 1b
	156
	157	mov fp, #0 @ Clear BSS (and zero fp)
	158	1: cmp r6, r7
	159	strcc fp, [r6],#4
	160	bcc 1b
	161
	162	ARM( ldmia r3, {r4, r5, r6, r7, sp})
	163	THUMB( ldmia r3, {r4, r5, r6, r7} )
	164	THUMB( ldr sp, [r3, #16] )
	165	str r9, [r4] @ Save processor ID
	166	str r1, [r5] @ Save machine type
	167	str r2, [r6] @ Save atags pointer
	168	bic r4, r0, #CR_A @ Clear 'A' bit
	169	stmia r7, {r0, r4} @ Save control register values
	170	b start_kernel
	171	ENDPROC(__mmap_switched)
	172
	173	.align 2
	174	.type __mmap_switched_data, %object
	175	__mmap_switched_data:
	176	.long __data_loc @ r4
a0a55682	177	.long _sdata @ r5
17bb5e2c RK	178	.long __bss_start @ r6
	179	.long _end @ r7
	180	.long processor_id @ r4
	181	.long __machine_arch_type @ r5
	182	.long __atags_pointer @ r6
	183	.long cr_alignment @ r7
	184	.long init_thread_union + THREAD_START_SP @ sp
	185	.size __mmap_switched_data, . - __mmap_switched_data
	186
	187	/*
	188	* This provides a C-API version of __lookup_machine_type
	189	*/
	190	ENTRY(lookup_machine_type)
	191	stmfd sp!, {r4 - r6, lr}
	192	mov r1, r0
	193	bl __lookup_machine_type
	194	mov r0, r5
	195	ldmfd sp!, {r4 - r6, pc}
	196	ENDPROC(lookup_machine_type)
	197
	198	/*
	199	* This provides a C-API version of __lookup_processor_type
	200	*/
	201	ENTRY(lookup_processor_type)
	202	stmfd sp!, {r4 - r6, r9, lr}
	203	mov r9, r0
	204	bl __lookup_processor_type
	205	mov r0, r5
	206	ldmfd sp!, {r4 - r6, r9, pc}
	207	ENDPROC(lookup_processor_type)
	208
5085f3ff RK	209	/*
	210	* Read processor ID register (CP#15, CR0), and look up in the linker-built
	211	* supported processor list. Note that we can't use the absolute addresses
	212	* for the __proc_info lists since we aren't running with the MMU on
	213	* (and therefore, we are not in the correct address space). We have to
	214	* calculate the offset.
	215	*
	216	* r9 = cpuid
	217	* Returns:
	218	* r3, r4, r6 corrupted
	219	* r5 = proc_info pointer in physical address space
	220	* r9 = cpuid (preserved)
	221	*/
	222	__CPUINIT
	223	__lookup_processor_type:
	224	adr r3, __lookup_processor_type_data
	225	ldmia r3, {r4 - r6}
	226	sub r3, r3, r4 @ get offset between virt&phys
	227	add r5, r5, r3 @ convert virt addresses to
	228	add r6, r6, r3 @ physical address space
	229	1: ldmia r5, {r3, r4} @ value, mask
	230	and r4, r4, r9 @ mask wanted bits
	231	teq r3, r4
	232	beq 2f
	233	add r5, r5, #PROC_INFO_SZ @ sizeof(proc_info_list)
	234	cmp r5, r6
	235	blo 1b
	236	mov r5, #0 @ unknown processor
	237	2: mov pc, lr
	238	ENDPROC(__lookup_processor_type)
	239
	240	/*
	241	* Look in <asm/procinfo.h> for information about the __proc_info structure.
	242	*/
	243	.align 2
	244	.type __lookup_processor_type_data, %object
	245	__lookup_processor_type_data:
	246	.long .
	247	.long __proc_info_begin
	248	.long __proc_info_end
	249	.size __lookup_processor_type_data, . - __lookup_processor_type_data
c083c660 RK	250
	251	__error_p:
	252	#ifdef CONFIG_DEBUG_LL
	253	adr r0, str_p1
	254	bl printascii
	255	mov r0, r9
	256	bl printhex8
	257	adr r0, str_p2
	258	bl printascii
	259	b __error
	260	str_p1: .asciz "\nError: unrecognized/unsupported processor variant (0x"
	261	str_p2: .asciz ").\n"
	262	.align
	263	#endif
	264	ENDPROC(__error_p)
	265
	266	__error:
	267	#ifdef CONFIG_ARCH_RPC
	268	/*
	269	* Turn the screen red on a error - RiscPC only.
	270	*/
	271	mov r0, #0x02000000
	272	mov r3, #0x11
	273	orr r3, r3, r3, lsl #8
	274	orr r3, r3, r3, lsl #16
	275	str r3, [r0], #4
	276	str r3, [r0], #4
	277	str r3, [r0], #4
	278	str r3, [r0], #4
	279	#endif
	280	1: mov r0, r0
	281	b 1b
	282	ENDPROC(__error)