[ARM] nommu: start-up code
Hyok S. Choi [Mon, 27 Mar 2006 13:58:25 +0000 (14:58 +0100)]
This patch adds nommu version start-up code head-nommu.S.
The common part of the start-up codes is moved to head-common.S.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Makefile
arch/arm/kernel/head-common.S [new file with mode: 0644]
arch/arm/kernel/head-nommu.S [new file with mode: 0644]
arch/arm/kernel/head.S

index fbfc14a..e3770ed 100644 (file)
@@ -69,7 +69,7 @@ AFLAGS                +=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float
 CHECKFLAGS     += -D__arm__
 
 #Default value
-head-y         := arch/arm/kernel/head.o arch/arm/kernel/init_task.o
+head-y         := arch/arm/kernel/head$(MMUEXT).o arch/arm/kernel/init_task.o
 textofs-y      := 0x00008000
 
  machine-$(CONFIG_ARCH_RPC)       := rpc
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
new file mode 100644 (file)
index 0000000..a52da0d
--- /dev/null
@@ -0,0 +1,217 @@
+/*
+ *  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.
+ *
+ */
+
+       .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 + THREAD_START_SP @ sp
+
+/*
+ * 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
+ *  r9  = processor ID
+ */
+       .type   __mmap_switched, %function
+__mmap_switched:
+       adr     r3, __switch_data + 4
+
+       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
+
+       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
+
+/*
+ * 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).
+ */
+
+       .type   __error_p, %function
+__error_p:
+#ifdef CONFIG_DEBUG_LL
+       adr     r0, str_p1
+       bl      printascii
+       b       __error
+str_p1:        .asciz  "\nError: unrecognized/unsupported processor variant.\n"
+       .align
+#endif
+
+       .type   __error_a, %function
+__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, 3f
+       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
+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
+/*
+ * 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
+
+
+/*
+ * 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)
+ */
+       .type   __lookup_processor_type, %function
+__lookup_processor_type:
+       adr     r3, 3f
+       ldmda   r3, {r5 - r7}
+       sub     r3, r3, r7                      @ 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
+
+/*
+ * 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}
+
+/*
+ * 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, #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
+
+/*
+ * 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}
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
new file mode 100644 (file)
index 0000000..b093ab8
--- /dev/null
@@ -0,0 +1,83 @@
+/*
+ *  linux/arch/arm/kernel/head-nommu.S
+ *
+ *  Copyright (C) 1994-2002 Russell King
+ *  Copyright (C) 2003-2006 Hyok S. Choi
+ *
+ * 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.
+ *
+ *  Common kernel startup code (non-paged MM)
+ *    for 32-bit CPUs which has a process ID register(CP15).
+ *
+ */
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include <asm/assembler.h>
+#include <asm/mach-types.h>
+#include <asm/procinfo.h>
+#include <asm/ptrace.h>
+#include <asm/constants.h>
+#include <asm/system.h>
+
+#define PROCINFO_INITFUNC       12
+
+/*
+ * Kernel startup entry point.
+ * ---------------------------
+ *
+ * This is normally called from the decompressor code.  The requirements
+ * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
+ * r1 = machine nr.
+ *
+ * See linux/arch/arm/tools/mach-types for the complete list of machine
+ * numbers for r1.
+ *
+ */
+       __INIT
+       .type   stext, %function
+ENTRY(stext)
+       msr     cpsr_c, #PSR_F_BIT | PSR_I_BIT | MODE_SVC @ 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)?
+       beq     __error_p                               @ yes, error 'p'
+       bl      __lookup_machine_type           @ r5=machinfo
+       movs    r8, r5                          @ invalid machine (r5=0)?
+       beq     __error_a                       @ yes, error 'a'
+
+       ldr     r13, __switch_data              @ address to jump to after
+                                               @ the initialization is done
+       adr     lr, __after_proc_init           @ return (PIC) address
+       add     pc, r10, #PROCINFO_INITFUNC
+
+/*
+ * Set the Control Register and Read the process ID.
+ */
+       .type   __after_proc_init, %function
+__after_proc_init:
+       mrc     p15, 0, r0, c1, c0, 0           @ read control reg
+#ifdef CONFIG_ALIGNMENT_TRAP
+       orr     r0, r0, #CR_A
+#else
+       bic     r0, r0, #CR_A
+#endif
+#ifdef CONFIG_CPU_DCACHE_DISABLE
+       bic     r0, r0, #CR_C
+#endif
+#ifdef CONFIG_CPU_BPREDICT_DISABLE
+       bic     r0, r0, #CR_Z
+#endif
+#ifdef CONFIG_CPU_ICACHE_DISABLE
+       bic     r0, r0, #CR_I
+#endif
+       mcr     p15, 0, r0, c1, c0, 0           @ write control reg
+
+       mov     pc, r13                         @ clear the BSS and jump
+                                               @ to start_kernel
+
+#include "head-common.S"
index 571d6d5..d848f3a 100644 (file)
@@ -103,49 +103,6 @@ ENTRY(stext)
        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 + THREAD_START_SP @ 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
-
-       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
-
-       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
-
 #if defined(CONFIG_SMP)
        .type   secondary_startup, #function
 ENTRY(secondary_startup)
@@ -368,166 +325,4 @@ __create_page_tables:
        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.
- *
- * 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).
- */
-
-       .type   __error_p, %function
-__error_p:
-#ifdef CONFIG_DEBUG_LL
-       adr     r0, str_p1
-       bl      printascii
-       b       __error
-str_p1:        .asciz  "\nError: unrecognized/unsupported processor variant.\n"
-       .align
-#endif
-
-       .type   __error_a, %function
-__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, 3f
-       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
-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
-/*
- * 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
-
-
-/*
- * 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)
- */
-       .type   __lookup_processor_type, %function
-__lookup_processor_type:
-       adr     r3, 3f
-       ldmda   r3, {r5 - r7}
-       sub     r3, r3, r7                      @ 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
-
-/*
- * 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}
-
-/*
- * 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, #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
-
-/*
- * 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"