diff options
Diffstat (limited to 'arch/arm/kernel/head-common.S')
| -rw-r--r-- | arch/arm/kernel/head-common.S | 309 |
1 files changed, 132 insertions, 177 deletions
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index b9505aa267c..572a38335c9 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -15,19 +15,57 @@ #define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2) #define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2) - .align 2 - .type __switch_data, %object -__switch_data: - .long __mmap_switched - .long __data_loc @ r4 - .long _data @ 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 +#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 + * 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 + +/* 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. 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, valid dtb pointer, or zero + * r5, r6 corrupted + */ +__vet_atags: + tst r2, #0x3 @ aligned? + bne 1f + + 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] + ldr r6, =ATAG_CORE + cmp r5, r6 + bne 1f + +2: mov pc, lr @ atag/dtb 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, @@ -35,11 +73,12 @@ __switch_data: * * r0 = cp#15 control register * r1 = machine ID - * r2 = atags pointer + * r2 = atags/dtb pointer * r9 = processor ID */ + __INIT __mmap_switched: - adr r3, __switch_data + 4 + adr r3, __mmap_switched_data ldmia r3!, {r4, r5, r6, r7} cmp r4, r5 @ Copy data segment if needed @@ -59,90 +98,42 @@ __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) -/* - * 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). - */ -__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_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, 4f - 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 + .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 +#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 -__error: -#ifdef CONFIG_ARCH_RPC /* - * Turn the screen red on a error - RiscPC only. + * This provides a C-API version of __lookup_processor_type */ - 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) +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) + __FINIT + .text /* * Read processor ID register (CP#15, CR0), and look up in the linker-built @@ -158,10 +149,9 @@ ENDPROC(__error) * r9 = cpuid (preserved) */ __lookup_processor_type: - adr r3, 3f - ldmia r3, {r5 - r7} - add r3, r3, #8 - sub r3, r3, r7 @ get offset between virt&phys + 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 @@ -176,92 +166,57 @@ __lookup_processor_type: ENDPROC(__lookup_processor_type) /* - * 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} -ENDPROC(lookup_processor_type) - -/* - * Look in <asm/procinfo.h> and arch/arm/kernel/arch.[ch] for - * more information about the __proc_info and __arch_info structures. + * Look in <asm/procinfo.h> for information about the __proc_info structure. */ .align 2 -3: .long __proc_info_begin + .type __lookup_processor_type_data, %object +__lookup_processor_type_data: + .long . + .long __proc_info_begin .long __proc_info_end -4: .long . - .long __arch_info_begin - .long __arch_info_end + .size __lookup_processor_type_data, . - __lookup_processor_type_data -/* - * 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, 4b - 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) +__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) -/* - * 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} -ENDPROC(lookup_machine_type) +__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) -/* 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 +__error: +#ifdef CONFIG_ARCH_RPC +/* + * Turn the screen red on a error - RiscPC only. */ -__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) + 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) |