diff options
Diffstat (limited to 'arch/arm/kernel/head-common.S')
| -rw-r--r-- | arch/arm/kernel/head-common.S | 48 |
1 files changed, 39 insertions, 9 deletions
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index c84b57d27d0..572a38335c9 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -15,6 +15,12 @@ #define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2) #define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2) +#ifdef CONFIG_CPU_BIG_ENDIAN +#define OF_DT_MAGIC 0xd00dfeed +#else +#define OF_DT_MAGIC 0xedfe0dd0 /* 0xd00dfeed in big-endian */ +#endif + /* * 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 @@ -28,20 +34,26 @@ /* 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 + * that the ATAG_CORE marker is first and present. If CONFIG_OF_FLATTREE + * is selected, then it will also accept a dtb pointer. 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. * * Returns: - * r2 either valid atags pointer, or zero + * r2 either valid atags pointer, valid dtb 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 + ldr r5, [r2, #0] +#ifdef CONFIG_OF_FLATTREE + ldr r6, =OF_DT_MAGIC @ is it a DTB? + cmp r5, r6 + beq 2f +#endif + cmp r5, #ATAG_CORE_SIZE @ is first tag ATAG_CORE? cmpne r5, #ATAG_CORE_SIZE_EMPTY bne 1f ldr r5, [r2, #4] @@ -49,7 +61,7 @@ __vet_atags: cmp r5, r6 bne 1f - mov pc, lr @ atag pointer is ok +2: mov pc, lr @ atag/dtb pointer is ok 1: mov r2, #0 mov pc, lr @@ -61,7 +73,7 @@ ENDPROC(__vet_atags) * * r0 = cp#15 control register * r1 = machine ID - * r2 = atags pointer + * r2 = atags/dtb pointer * r9 = processor ID */ __INIT @@ -86,8 +98,8 @@ __mmap_switched: 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 + cmp r7, #0 + strne r0, [r7] @ Save control register values b start_kernel ENDPROC(__mmap_switched) @@ -101,7 +113,11 @@ __mmap_switched_data: .long processor_id @ r4 .long __machine_arch_type @ r5 .long __atags_pointer @ r6 +#ifdef CONFIG_CPU_CP15 .long cr_alignment @ r7 +#else + .long 0 @ r7 +#endif .long init_thread_union + THREAD_START_SP @ sp .size __mmap_switched_data, . - __mmap_switched_data @@ -116,6 +132,9 @@ ENTRY(lookup_processor_type) ldmfd sp!, {r4 - r6, r9, pc} ENDPROC(lookup_processor_type) + __FINIT + .text + /* * 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 @@ -129,7 +148,6 @@ ENDPROC(lookup_processor_type) * 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} @@ -158,6 +176,18 @@ __lookup_processor_type_data: .long __proc_info_end .size __lookup_processor_type_data, . - __lookup_processor_type_data +__error_lpae: +#ifdef CONFIG_DEBUG_LL + adr r0, str_lpae + bl printascii + b __error +str_lpae: .asciz "\nError: Kernel with LPAE support, but CPU does not support LPAE.\n" +#else + b __error +#endif + .align +ENDPROC(__error_lpae) + __error_p: #ifdef CONFIG_DEBUG_LL adr r0, str_p1 |