X-Git-Url: http://nv-tegra.nvidia.com/gitweb/?p=linux-3.10.git;a=blobdiff_plain;f=arch%2Farm%2Fkernel%2Fhead-common.S;h=93ad576b2d74b311331542f6a79fc4054a0306d8;hp=a52da0ddb43d01b26821c4e6c98f59bbe92d4f84;hb=b86040a59feb255a8193173caa4d5199464433d5;hpb=75d90832d58aa5855972cfc2bdaa94970ccd4aca

diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index a52da0d..93ad576 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -11,16 +11,21 @@
  *
  */
 
+#define ATAG_CORE 0x54410001
+#define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2)
+
+	.align	2
 	.type	__switch_data, %object
 __switch_data:
 	.long	__mmap_switched
 	.long	__data_loc			@ r4
-	.long	__data_start			@ r5
+	.long	_data				@ r5
 	.long	__bss_start			@ r6
 	.long	_end				@ r7
 	.long	processor_id			@ r4
 	.long	__machine_arch_type		@ r5
-	.long	cr_alignment			@ r6
+	.long	__atags_pointer			@ r6
+	.long	cr_alignment			@ r7
 	.long	init_thread_union + THREAD_START_SP @ sp
 
 /*
@@ -29,9 +34,9 @@ __switch_data:
  *
  *  r0  = cp#15 control register
  *  r1  = machine ID
+ *  r2  = atags pointer
  *  r9  = processor ID
  */
-	.type	__mmap_switched, %function
 __mmap_switched:
 	adr	r3, __switch_data + 4
 
@@ -47,12 +52,16 @@ __mmap_switched:
 	strcc	fp, [r6],#4
 	bcc	1b
 
-	ldmia	r3, {r4, r5, r6, sp}
+ 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	r6, {r0, r4}			@ Save control register values
+	stmia	r7, {r0, r4}			@ Save control register values
 	b	start_kernel
+ENDPROC(__mmap_switched)
 
 /*
  * Exception handling.  Something went wrong and we can't proceed.  We
@@ -63,18 +72,21 @@ __mmap_switched:
  * 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
+	mov	r0, r9
+	bl	printhex8
+	adr	r0, str_p2
+	bl	printascii
 	b	__error
-str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant.\n"
+str_p1:	.asciz	"\nError: unrecognized/unsupported processor variant (0x"
+str_p2:	.asciz	").\n"
 	.align
 #endif
+ENDPROC(__error_p)
 
-	.type	__error_a, %function
 __error_a:
 #ifdef CONFIG_DEBUG_LL
 	mov	r4, r1				@ preserve machine ID
@@ -104,13 +116,14 @@ __error_a:
 	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
 #endif
 
-	.type	__error, %function
 __error:
 #ifdef CONFIG_ARCH_RPC
 /*
@@ -127,6 +140,7 @@ __error:
 #endif
 1:	mov	r0, r0
 	b	1b
+ENDPROC(__error)
 
 
 /*
@@ -142,10 +156,10 @@ __error:
  *	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}
+	ldmia	r3, {r5 - r7}
+	add	r3, r3, #8
 	sub	r3, r3, r7			@ get offset between virt&phys
 	add	r5, r5, r3			@ convert virt addresses to
 	add	r6, r6, r3			@ physical address space
@@ -158,6 +172,7 @@ __lookup_processor_type:
 	blo	1b
 	mov	r5, #0				@ unknown processor
 2:	mov	pc, lr
+ENDPROC(__lookup_processor_type)
 
 /*
  * This provides a C-API version of the above function.
@@ -168,14 +183,16 @@ ENTRY(lookup_processor_type)
 	bl	__lookup_processor_type
 	mov	r0, r5
 	ldmfd	sp!, {r4 - r7, r9, pc}
+ENDPROC(lookup_processor_type)
 
 /*
- * Look in include/asm-arm/procinfo.h and arch/arm/kernel/arch.[ch] for
+ * Look in <asm/procinfo.h> and arch/arm/kernel/arch.[ch] for
  * more information about the __proc_info and __arch_info structures.
  */
-	.long	__proc_info_begin
+	.align	2
+3:	.long	__proc_info_begin
 	.long	__proc_info_end
-3:	.long	.
+4:	.long	.
 	.long	__arch_info_begin
 	.long	__arch_info_end
 
@@ -190,9 +207,8 @@ ENTRY(lookup_processor_type)
  *  r3, r4, r6 corrupted
  *  r5 = mach_info pointer in physical address space
  */
-	.type	__lookup_machine_type, %function
 __lookup_machine_type:
-	adr	r3, 3b
+	adr	r3, 4b
 	ldmia	r3, {r4, r5, r6}
 	sub	r3, r3, r4			@ get offset between virt&phys
 	add	r5, r5, r3			@ convert virt addresses to
@@ -205,6 +221,7 @@ __lookup_machine_type:
 	blo	1b
 	mov	r5, #0				@ unknown machine
 2:	mov	pc, lr
+ENDPROC(__lookup_machine_type)
 
 /*
  * This provides a C-API version of the above function.
@@ -215,3 +232,34 @@ ENTRY(lookup_machine_type)
 	bl	__lookup_machine_type
 	mov	r0, r5
 	ldmfd	sp!, {r4 - r6, pc}
+ENDPROC(lookup_machine_type)
+
+/* 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?
+	subs	r5, r5, #ATAG_CORE_SIZE
+	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)