* linux/arch/arm/kernel/head.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
*
* Kernel startup code for all 32-bit CPUs
*/
-#include <linux/config.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/domain.h>
-#include <asm/mach-types.h>
-#include <asm/procinfo.h>
#include <asm/ptrace.h>
-#include <asm/constants.h>
+#include <asm/asm-offsets.h>
+#include <asm/memory.h>
+#include <asm/thread_info.h>
#include <asm/system.h>
-#define PROCINFO_MMUFLAGS 8
-#define PROCINFO_INITFUNC 12
-
-#define MACHINFO_PHYSRAM 4
-#define MACHINFO_PHYSIO 8
-#define MACHINFO_PGOFFIO 12
-
-#ifndef CONFIG_XIP_KERNEL
-/*
- * We place the page tables 16K below TEXTADDR. Therefore, we must make sure
- * that TEXTADDR is correctly set. Currently, we expect the least significant
- * 16 bits to be 0x8000, but we could probably relax this restriction to
- * TEXTADDR >= PAGE_OFFSET + 0x4000
- *
- * Note that swapper_pg_dir is the virtual address of the page tables, and
- * pgtbl gives us a position-independent reference to these tables. We can
- * do this because stext == TEXTADDR
- */
-#if (TEXTADDR & 0xffff) != 0x8000
-#error TEXTADDR must start at 0xXXXX8000
+#if (PHYS_OFFSET & 0x001fffff)
+#error "PHYS_OFFSET must be at an even 2MiB boundary!"
#endif
- .globl swapper_pg_dir
- .equ swapper_pg_dir, TEXTADDR - 0x4000
+#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
+#define KERNEL_RAM_PADDR (PHYS_OFFSET + TEXT_OFFSET)
- .macro pgtbl, rd, phys
- adr \rd, stext
- sub \rd, \rd, #0x4000
- .endm
-#else
/*
- * XIP Kernel:
- *
- * We place the page tables 16K below DATAADDR. Therefore, we must make sure
- * that DATAADDR is correctly set. Currently, we expect the least significant
- * 16 bits to be 0x8000, but we could probably relax this restriction to
- * DATAADDR >= PAGE_OFFSET + 0x4000
- *
- * Note that pgtbl is meant to return the physical address of swapper_pg_dir.
- * We can't make it relative to the kernel position in this case since
- * the kernel can physically be anywhere.
+ * swapper_pg_dir is the virtual address of the initial page table.
+ * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must
+ * make sure that KERNEL_RAM_VADDR is correctly set. Currently, we expect
+ * the least significant 16 bits to be 0x8000, but we could probably
+ * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
*/
-#if (DATAADDR & 0xffff) != 0x8000
-#error DATAADDR must start at 0xXXXX8000
+#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
+#error KERNEL_RAM_VADDR must start at 0xXXXX8000
#endif
.globl swapper_pg_dir
- .equ swapper_pg_dir, DATAADDR - 0x4000
+ .equ swapper_pg_dir, KERNEL_RAM_VADDR - 0x4000
- .macro pgtbl, rd, phys
- ldr \rd, =((DATAADDR - 0x4000) - VIRT_OFFSET)
- add \rd, \rd, \phys
+ .macro pgtbl, rd
+ ldr \rd, =(KERNEL_RAM_PADDR - 0x4000)
.endm
+
+#ifdef CONFIG_XIP_KERNEL
+#define TEXTADDR XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
+#else
+#define TEXTADDR KERNEL_RAM_VADDR
#endif
/*
__INIT
.type stext, %function
ENTRY(stext)
- msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ ensure svc mode
+ msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ 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)?
- moveq r0, #'p' @ yes, error 'p'
- beq __error
+ beq __error_p @ yes, error 'p'
bl __lookup_machine_type @ r5=machinfo
movs r8, r5 @ invalid machine (r5=0)?
- moveq r0, #'a' @ yes, error 'a'
- beq __error
+ beq __error_a @ yes, error 'a'
bl __create_page_tables
/*
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+8192 @ 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
+#if defined(CONFIG_SMP)
+ .type secondary_startup, #function
+ENTRY(secondary_startup)
+ /*
+ * Common entry point for secondary CPUs.
+ *
+ * Ensure that we're in SVC mode, and IRQs are disabled. Lookup
+ * the processor type - there is no need to check the machine type
+ * as it has already been validated by the primary processor.
+ */
+ msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
+ mrc p15, 0, r9, c0, c0 @ get processor id
+ bl __lookup_processor_type
+ movs r10, r5 @ invalid processor?
+ moveq r0, #'p' @ yes, error 'p'
+ beq __error
- 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
+ /*
+ * Use the page tables supplied from __cpu_up.
+ */
+ adr r4, __secondary_data
+ ldmia r4, {r5, r7, r13} @ address to jump to after
+ sub r4, r4, r5 @ mmu has been enabled
+ ldr r4, [r7, r4] @ get secondary_data.pgdir
+ adr lr, __enable_mmu @ return address
+ add pc, r10, #PROCINFO_INITFUNC @ initialise processor
+ @ (return control reg)
- mov fp, #0 @ Clear BSS (and zero fp)
-1: cmp r6, r7
- strcc fp, [r6],#4
- bcc 1b
+ /*
+ * r6 = &secondary_data
+ */
+ENTRY(__secondary_switched)
+ ldr sp, [r7, #4] @ get secondary_data.stack
+ mov fp, #0
+ b secondary_start_kernel
- 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
+ .type __secondary_data, %object
+__secondary_data:
+ .long .
+ .long secondary_data
+ .long __secondary_switched
+#endif /* defined(CONFIG_SMP) */
* r10 = procinfo
*
* Returns:
- * r0, r3, r5, r6, r7 corrupted
+ * r0, r3, r6, r7 corrupted
* r4 = physical page table address
*/
.type __create_page_tables, %function
__create_page_tables:
- ldr r5, [r8, #MACHINFO_PHYSRAM] @ physram
- pgtbl r4, r5 @ page table address
+ pgtbl r4 @ page table address
/*
* Clear the 16K level 1 swapper page table
teq r0, r6
bne 1b
- ldr r7, [r10, #PROCINFO_MMUFLAGS] @ mmuflags
+ ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
/*
* Create identity mapping for first MB of kernel to
/*
* Now setup the pagetables for our kernel direct
- * mapped region. We round TEXTADDR down to the
- * nearest megabyte boundary. It is assumed that
- * the kernel fits within 4 contigous 1MB sections.
+ * mapped region.
*/
add r0, r4, #(TEXTADDR & 0xff000000) >> 18 @ start of kernel
str r3, [r0, #(TEXTADDR & 0x00f00000) >> 18]!
- add r3, r3, #1 << 20
- str r3, [r0, #4]! @ KERNEL + 1MB
- add r3, r3, #1 << 20
- str r3, [r0, #4]! @ KERNEL + 2MB
- add r3, r3, #1 << 20
- str r3, [r0, #4] @ KERNEL + 3MB
+
+ ldr r6, =(_end - PAGE_OFFSET - 1) @ r6 = number of sections
+ mov r6, r6, lsr #20 @ needed for kernel minus 1
+
+1: add r3, r3, #1 << 20
+ str r3, [r0, #4]!
+ subs r6, r6, #1
+ bgt 1b
/*
* Then map first 1MB of ram in case it contains our boot params.
*/
- add r0, r4, #VIRT_OFFSET >> 18
- orr r6, r5, r7
+ add r0, r4, #PAGE_OFFSET >> 18
+ orr r6, r7, #(PHYS_OFFSET & 0xff000000)
+ orr r6, r6, #(PHYS_OFFSET & 0x00e00000)
str r6, [r0]
#ifdef CONFIG_XIP_KERNEL
* Map some ram to cover our .data and .bss areas.
* Mapping 3MB should be plenty.
*/
- sub r3, r4, r5
+ sub r3, r4, #PHYS_OFFSET
mov r3, r3, lsr #20
add r0, r0, r3, lsl #2
add r6, r6, r3, lsl #20
str r6, [r0]
#endif
- bic r7, r7, #0x0c @ turn off cacheable
- @ and bufferable bits
#ifdef CONFIG_DEBUG_LL
+ ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
/*
* Map in IO space for serial debugging.
* This allows debug messages to be output
bne 1b
#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
/*
- * If we're using the NetWinder, we need to map in
- * the 16550-type serial port for the debug messages
+ * If we're using the NetWinder or CATS, we also need to map
+ * in the 16550-type serial port for the debug messages
*/
- teq r1, #MACH_TYPE_NETWINDER
- teqne r1, #MACH_TYPE_CATS
- bne 1f
- add r0, r4, #0x3fc0 @ ff000000
- mov r3, #0x7c000000
- orr r3, r3, r7
- str r3, [r0], #4
- add r3, r3, #1 << 20
- str r3, [r0], #4
-1:
-#endif
+ add r0, r4, #0xff000000 >> 18
+ orr r3, r7, #0x7c000000
+ str r3, [r0]
#endif
#ifdef CONFIG_ARCH_RPC
/*
* Similar reasons here - for debug. This is
* only for Acorn RiscPC architectures.
*/
- add r0, r4, #0x80 @ 02000000
- mov r3, #0x02000000
- orr r3, r3, r7
+ add r0, r4, #0x02000000 >> 18
+ orr r3, r7, #0x02000000
str r3, [r0]
- add r0, r4, #0x3600 @ d8000000
+ add r0, r4, #0xd8000000 >> 18
str r3, [r0]
+#endif
#endif
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.
- *
- * r0 = ascii error character:
- * a = invalid architecture
- * p = invalid processor
- * i = invalid calling convention
- *
- * Generally, only serious errors cause this.
- */
- .type __error, %function
-__error:
-#ifdef CONFIG_DEBUG_LL
- mov r8, r0 @ preserve r0
- adr r0, err_str
- bl printascii
- mov r0, r8
- bl printch
-#endif
-#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
-
-#ifdef CONFIG_DEBUG_LL
- .type err_str, %object
-err_str:
- .asciz "\nError: "
- .align
-#endif
-
-/*
- * 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.
- *
- * Returns:
- * r3, r4, r6 corrupted
- * r5 = proc_info pointer in physical address space
- * r9 = cpuid
- */
- .type __lookup_processor_type, %function
-__lookup_processor_type:
- adr r3, 3f
- ldmda r3, {r5, r6, r9}
- sub r3, r3, r9 @ get offset between virt&phys
- add r5, r5, r3 @ convert virt addresses to
- add r6, r6, r3 @ physical address space
- mrc p15, 0, r9, c0, c0 @ get processor id
-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
- blt 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 - r6, r9, lr}
- bl __lookup_processor_type
- mov r0, r5
- ldmfd sp!, {r4 - r6, 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] @ get machine type
- teq r3, r1 @ matches loader number?
- beq 2f @ found
- add r5, r5, #SIZEOF_MACHINE_DESC @ next machine_desc
- cmp r5, r6
- blt 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"
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