Hi,

I try to port linux kernel 2.6.23 on TMS320DM355 DVEVM,
and the booting process is not action as following:

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2048 MiB
In:    serial
Out:   serial
Err:   serial
ARM Clock :- 216MHz
DDR Clock :- 171MHz
Hit any key to stop autoboot:  0
BOOTP broadcast 1
DHCP client bound to address 192.168.1.101
TFTP from server 192.168.1.12; our IP address is 192.168.1.101
Filename 'uImage-android'.
Load address: 0x80700000
Loading: #################################################################
       #################################################################
       #################################################################
       #################################################################
       #################################################################
       #################
done
Bytes transferred = 1746832 (1aa790 hex)
## Booting image at 80700000 ...
 Image Name:   Linux-2.6.23
 Image Type:   ARM Linux Kernel Image (uncompressed)
 Data Size:    1746768 Bytes =  1.7 MB
 Load Address: 80008000
 Entry Point:  80008000
 Verifying Checksum ... OK
OK

Starting kernel ...

Uncompressing Linux................................................................................................................... done, booting the kernel.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I try to trace code at file: kernel/arch/arm/boot/compressed/head.S (see the attached file)

I trace the code and don't know the next step at line 275:

add   pc, r5, r0   @ call relocation code

Could anyone tell me the possible running code at line 275,

Thanks

YenHung Chen
/*
 *  linux/arch/arm/boot/compressed/head.S
 *
 *  Copyright (C) 1996-2002 Russell King
 *  Copyright (C) 2004 Hyok S. Choi (MPU support)
 *
 * 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.
 */
#include <linux/linkage.h>

/*
 * Debugging stuff
 *
 * Note that these macros must not contain any code which is not
 * 100% relocatable.  Any attempt to do so will result in a crash.
 * Please select one of the following when turning on debugging.
 */
#ifdef DEBUG

#if defined(CONFIG_DEBUG_ICEDCC)

#ifdef CONFIG_CPU_V6
                .macro  loadsp, rb
                .endm
                .macro  writeb, ch, rb
                mcr     p14, 0, \ch, c0, c5, 0
                .endm
#else
                .macro  loadsp, rb
                .endm
                .macro  writeb, ch, rb
                mcr     p14, 0, \ch, c0, c1, 0
                .endm
#endif

#else

#include <asm/arch/debug-macro.S>

                .macro  writeb, ch, rb
                senduart \ch, \rb
                .endm

#if defined(CONFIG_ARCH_SA1100)
                .macro  loadsp, rb
                mov     \rb, #0x80000000        @ physical base address
#ifdef CONFIG_DEBUG_LL_SER3
                add     \rb, \rb, #0x00050000   @ Ser3
#else
                add     \rb, \rb, #0x00010000   @ Ser1
#endif
                .endm
#elif defined(CONFIG_ARCH_S3C2410)
                .macro loadsp, rb
                mov     \rb, #0x50000000
                add     \rb, \rb, #0x4000 * CONFIG_S3C_LOWLEVEL_UART_PORT
                .endm
#else
                .macro  loadsp, rb
                addruart \rb
                .endm
#endif
#endif
#endif

                .macro  kputc,val
                mov     r0, \val
                bl      putc
                .endm

                .macro  kphex,val,len
                mov     r0, \val
                mov     r1, #\len
                bl      phex
                .endm

                .macro  debug_reloc_start
#ifdef DEBUG
                kputc   #'\n'
                kphex   r6, 8           /* processor id */
                kputc   #':'
                kphex   r7, 8           /* architecture id */
#ifdef CONFIG_CPU_CP15
                kputc   #':'
                mrc     p15, 0, r0, c1, c0
                kphex   r0, 8           /* control reg */
#endif
                kputc   #'\n'
                kphex   r5, 8           /* decompressed kernel start */
                kputc   #'-'
                kphex   r9, 8           /* decompressed kernel end  */
                kputc   #'>'
                kphex   r4, 8           /* kernel execution address */
                kputc   #'\n'
#endif
                .endm

                .macro  debug_reloc_end
#ifdef DEBUG
                kphex   r5, 8           /* end of kernel */
                kputc   #'\n'
                mov     r0, r4
                bl      memdump         /* dump 256 bytes at start of kernel */
#endif
                .endm

                .section ".start", #alloc, #execinstr
/*
 * sort out different calling conventions
 */
                .align
start:
                .type   start,#function
                .rept   8
                mov     r0, r0
                .endr

                b       1f
                .word   0x016f2818              @ Magic numbers to help the 
loader
                .word   start                   @ absolute load/run zImage 
address
                .word   _edata                  @ zImage end address
1:              mov     r7, r1                  @ save architecture ID
                mov     r8, r2                  @ save atags pointer

#ifndef __ARM_ARCH_2__
                /*
                 * Booting from Angel - need to enter SVC mode and disable
                 * FIQs/IRQs (numeric definitions from angel arm.h source).
                 * We only do this if we were in user mode on entry.
                 */
                mrs     r2, cpsr                @ get current mode
                tst     r2, #3                  @ not user?
                bne     not_angel
                mov     r0, #0x17               @ angel_SWIreason_EnterSVC
                swi     0x123456                @ angel_SWI_ARM
not_angel:
                mrs     r2, cpsr                @ turn off interrupts to
                orr     r2, r2, #0xc0           @ prevent angel from running
                msr     cpsr_c, r2
#else
                teqp    pc, #0x0c000003         @ turn off interrupts
#endif

                /*
                 * Note that some cache flushing and other stuff may
                 * be needed here - is there an Angel SWI call for this?
                 */

                /*
                 * some architecture specific code can be inserted
                 * by the linker here, but it should preserve r7, r8, and r9.
                 */

                .text
                adr     r0, LC0
                ldmia   r0, {r1, r2, r3, r4, r5, r6, ip, sp}
                subs    r0, r0, r1              @ calculate the delta offset

                                                @ if delta is zero, we are
                beq     not_relocated           @ running at the address we
                                                @ were linked at.

                /*
                 * We're running at a different address.  We need to fix
                 * up various pointers:
                 *   r5 - zImage base address
                 *   r6 - GOT start
                 *   ip - GOT end
                 */
                add     r5, r5, r0
                add     r6, r6, r0
                add     ip, ip, r0

#ifndef CONFIG_ZBOOT_ROM
                /*
                 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
                 * we need to fix up pointers into the BSS region.
                 *   r2 - BSS start
                 *   r3 - BSS end
                 *   sp - stack pointer
                 */
                add     r2, r2, r0
                add     r3, r3, r0
                add     sp, sp, r0

                /*
                 * Relocate all entries in the GOT table.
                 */
1:              ldr     r1, [r6, #0]            @ relocate entries in the GOT
                add     r1, r1, r0              @ table.  This fixes up the
                str     r1, [r6], #4            @ C references.
                cmp     r6, ip
                blo     1b
#else

                /*
                 * Relocate entries in the GOT table.  We only relocate
                 * the entries that are outside the (relocated) BSS region.
                 */
1:              ldr     r1, [r6, #0]            @ relocate entries in the GOT
                cmp     r1, r2                  @ entry < bss_start ||
                cmphs   r3, r1                  @ _end < entry
                addlo   r1, r1, r0              @ table.  This fixes up the
                str     r1, [r6], #4            @ C references.
                cmp     r6, ip
                blo     1b
#endif

not_relocated:  mov     r0, #0
1:              str     r0, [r2], #4            @ clear bss
                str     r0, [r2], #4
                str     r0, [r2], #4
                str     r0, [r2], #4
                cmp     r2, r3
                blo     1b

                /*
                 * The C runtime environment should now be setup
                 * sufficiently.  Turn the cache on, set up some
                 * pointers, and start decompressing.
                 */
                bl      cache_on

                mov     r1, sp                  @ malloc space above stack
                add     r2, sp, #0x10000        @ 64k max

/*
 * Check to see if we will overwrite ourselves.
 *   r4 = final kernel address
 *   r5 = start of this image
 *   r2 = end of malloc space (and therefore this image)
 * We basically want:
 *   r4 >= r2 -> OK
 *   r4 + image length <= r5 -> OK
 */
                cmp     r4, r2
                bhs     wont_overwrite
                sub     r3, sp, r5              @ > compressed kernel size
                add     r0, r4, r3, lsl #2      @ allow for 4x expansion
                cmp     r0, r5
                bls     wont_overwrite

                mov     r5, r2                  @ decompress after malloc space
                mov     r0, r5
                mov     r3, r7
                bl      decompress_kernel

                add     r0, r0, #127 + 128      @ alignment + stack
                bic     r0, r0, #127            @ align the kernel length
/*
 * r0     = decompressed kernel length
 * r1-r3  = unused
 * r4     = kernel execution address
 * r5     = decompressed kernel start
 * r6     = processor ID
 * r7     = architecture ID
 * r8     = atags pointer
 * r9-r14 = corrupted
 */
                add     r1, r5, r0              @ end of decompressed kernel
                adr     r2, reloc_start
                ldr     r3, LC1
                add     r3, r2, r3
1:              ldmia   r2!, {r9 - r14}         @ copy relocation code
                stmia   r1!, {r9 - r14}
                ldmia   r2!, {r9 - r14}
                stmia   r1!, {r9 - r14}
                cmp     r2, r3
                blo     1b
                add     sp, r1, #128            @ relocate the stack

                bl      cache_clean_flush
                add     pc, r5, r0              @ call relocation code

/*
 * We're not in danger of overwriting ourselves.  Do this the simple way.
 *
 * r4     = kernel execution address
 * r7     = architecture ID
 */
wont_overwrite: mov     r0, r4
                mov     r3, r7
                bl      decompress_kernel
                b       call_kernel

                .type   LC0, #object
LC0:            .word   LC0                     @ r1
                .word   __bss_start             @ r2
                .word   _end                    @ r3
                .word   zreladdr                @ r4
                .word   _start                  @ r5
                .word   _got_start              @ r6
                .word   _got_end                @ ip
                .word   user_stack+4096         @ sp
LC1:            .word   reloc_end - reloc_start
                .size   LC0, . - LC0

#ifdef CONFIG_ARCH_RPC
                .globl  params
params:         ldr     r0, =params_phys
                mov     pc, lr
                .ltorg
                .align
#endif

/*
 * Turn on the cache.  We need to setup some page tables so that we
 * can have both the I and D caches on.
 *
 * We place the page tables 16k down from the kernel execution address,
 * and we hope that nothing else is using it.  If we're using it, we
 * will go pop!
 *
 * On entry,
 *  r4 = kernel execution address
 *  r6 = processor ID
 *  r7 = architecture number
 *  r8 = atags pointer
 *  r9 = run-time address of "start"  (???)
 * On exit,
 *  r1, r2, r3, r9, r10, r12 corrupted
 * This routine must preserve:
 *  r4, r5, r6, r7, r8
 */
                .align  5
cache_on:       mov     r3, #8                  @ cache_on function
                b       call_cache_fn

/*
 * Initialize the highest priority protection region, PR7
 * to cover all 32bit address and cacheable and bufferable.
 */
__armv4_mpu_cache_on:
                mov     r0, #0x3f               @ 4G, the whole
                mcr     p15, 0, r0, c6, c7, 0   @ PR7 Area Setting
                mcr     p15, 0, r0, c6, c7, 1

                mov     r0, #0x80               @ PR7
                mcr     p15, 0, r0, c2, c0, 0   @ D-cache on
                mcr     p15, 0, r0, c2, c0, 1   @ I-cache on
                mcr     p15, 0, r0, c3, c0, 0   @ write-buffer on

                mov     r0, #0xc000
                mcr     p15, 0, r0, c5, c0, 1   @ I-access permission
                mcr     p15, 0, r0, c5, c0, 0   @ D-access permission

                mov     r0, #0
                mcr     p15, 0, r0, c7, c10, 4  @ drain write buffer
                mcr     p15, 0, r0, c7, c5, 0   @ flush(inval) I-Cache
                mcr     p15, 0, r0, c7, c6, 0   @ flush(inval) D-Cache
                mrc     p15, 0, r0, c1, c0, 0   @ read control reg
                                                @ ...I .... ..D. WC.M
                orr     r0, r0, #0x002d         @ .... .... ..1. 11.1
                orr     r0, r0, #0x1000         @ ...1 .... .... ....

                mcr     p15, 0, r0, c1, c0, 0   @ write control reg

                mov     r0, #0
                mcr     p15, 0, r0, c7, c5, 0   @ flush(inval) I-Cache
                mcr     p15, 0, r0, c7, c6, 0   @ flush(inval) D-Cache
                mov     pc, lr

__armv3_mpu_cache_on:
                mov     r0, #0x3f               @ 4G, the whole
                mcr     p15, 0, r0, c6, c7, 0   @ PR7 Area Setting

                mov     r0, #0x80               @ PR7
                mcr     p15, 0, r0, c2, c0, 0   @ cache on
                mcr     p15, 0, r0, c3, c0, 0   @ write-buffer on

                mov     r0, #0xc000
                mcr     p15, 0, r0, c5, c0, 0   @ access permission

                mov     r0, #0
                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mrc     p15, 0, r0, c1, c0, 0   @ read control reg
                                                @ .... .... .... WC.M
                orr     r0, r0, #0x000d         @ .... .... .... 11.1
                mov     r0, #0
                mcr     p15, 0, r0, c1, c0, 0   @ write control reg

                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mov     pc, lr

__setup_mmu:    sub     r3, r4, #16384          @ Page directory size
                bic     r3, r3, #0xff           @ Align the pointer
                bic     r3, r3, #0x3f00
/*
 * Initialise the page tables, turning on the cacheable and bufferable
 * bits for the RAM area only.
 */
                mov     r0, r3
                mov     r9, r0, lsr #18
                mov     r9, r9, lsl #18         @ start of RAM
                add     r10, r9, #0x10000000    @ a reasonable RAM size
                mov     r1, #0x12
                orr     r1, r1, #3 << 10
                add     r2, r3, #16384
1:              cmp     r1, r9                  @ if virt > start of RAM
                orrhs   r1, r1, #0x0c           @ set cacheable, bufferable
                cmp     r1, r10                 @ if virt > end of RAM
                bichs   r1, r1, #0x0c           @ clear cacheable, bufferable
                str     r1, [r0], #4            @ 1:1 mapping
                add     r1, r1, #1048576
                teq     r0, r2
                bne     1b
/*
 * If ever we are running from Flash, then we surely want the cache
 * to be enabled also for our execution instance...  We map 2MB of it
 * so there is no map overlap problem for up to 1 MB compressed kernel.
 * If the execution is in RAM then we would only be duplicating the above.
 */
                mov     r1, #0x1e
                orr     r1, r1, #3 << 10
                mov     r2, pc, lsr #20
                orr     r1, r1, r2, lsl #20
                add     r0, r3, r2, lsl #2
                str     r1, [r0], #4
                add     r1, r1, #1048576
                str     r1, [r0]
                mov     pc, lr

__armv4_mmu_cache_on:
                mov     r12, lr
                bl      __setup_mmu
                mov     r0, #0
                mcr     p15, 0, r0, c7, c10, 4  @ drain write buffer
                mcr     p15, 0, r0, c8, c7, 0   @ flush I,D TLBs
                mrc     p15, 0, r0, c1, c0, 0   @ read control reg
                orr     r0, r0, #0x5000         @ I-cache enable, RR cache 
replacement
                orr     r0, r0, #0x0030
                bl      __common_mmu_cache_on
                mov     r0, #0
                mcr     p15, 0, r0, c8, c7, 0   @ flush I,D TLBs
                mov     pc, r12

__armv7_mmu_cache_on:
                mov     r12, lr
                mrc     p15, 0, r11, c0, c1, 4  @ read ID_MMFR0
                tst     r11, #0xf               @ VMSA
                blne    __setup_mmu
                mov     r0, #0
                mcr     p15, 0, r0, c7, c10, 4  @ drain write buffer
                tst     r11, #0xf               @ VMSA
                mcrne   p15, 0, r0, c8, c7, 0   @ flush I,D TLBs
                mrc     p15, 0, r0, c1, c0, 0   @ read control reg
                orr     r0, r0, #0x5000         @ I-cache enable, RR cache 
replacement
                orr     r0, r0, #0x003c         @ write buffer
                orrne   r0, r0, #1              @ MMU enabled
                movne   r1, #-1
                mcrne   p15, 0, r3, c2, c0, 0   @ load page table pointer
                mcrne   p15, 0, r1, c3, c0, 0   @ load domain access control
                mcr     p15, 0, r0, c1, c0, 0   @ load control register
                mrc     p15, 0, r0, c1, c0, 0   @ and read it back
                mov     r0, #0
                mcr     p15, 0, r0, c7, c5, 4   @ ISB
                mov     pc, r12

__arm6_mmu_cache_on:
                mov     r12, lr
                bl      __setup_mmu
                mov     r0, #0
                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mcr     p15, 0, r0, c5, c0, 0   @ invalidate whole TLB v3
                mov     r0, #0x30
                bl      __common_mmu_cache_on
                mov     r0, #0
                mcr     p15, 0, r0, c5, c0, 0   @ invalidate whole TLB v3
                mov     pc, r12

__common_mmu_cache_on:
#ifndef DEBUG
                orr     r0, r0, #0x000d         @ Write buffer, mmu
#endif
                mov     r1, #-1
                mcr     p15, 0, r3, c2, c0, 0   @ load page table pointer
                mcr     p15, 0, r1, c3, c0, 0   @ load domain access control
                b       1f
                .align  5                       @ cache line aligned
1:              mcr     p15, 0, r0, c1, c0, 0   @ load control register
                mrc     p15, 0, r0, c1, c0, 0   @ and read it back to
                sub     pc, lr, r0, lsr #32     @ properly flush pipeline

/*
 * All code following this line is relocatable.  It is relocated by
 * the above code to the end of the decompressed kernel image and
 * executed there.  During this time, we have no stacks.
 *
 * r0     = decompressed kernel length
 * r1-r3  = unused
 * r4     = kernel execution address
 * r5     = decompressed kernel start
 * r6     = processor ID
 * r7     = architecture ID
 * r8     = atags pointer
 * r9-r14 = corrupted
 */
                .align  5
reloc_start:    add     r9, r5, r0
                sub     r9, r9, #128            @ do not copy the stack
                debug_reloc_start
                mov     r1, r4
1:
                .rept   4
                ldmia   r5!, {r0, r2, r3, r10 - r14}    @ relocate kernel
                stmia   r1!, {r0, r2, r3, r10 - r14}
                .endr

                cmp     r5, r9
                blo     1b
                add     sp, r1, #128            @ relocate the stack
                debug_reloc_end

call_kernel:    bl      cache_clean_flush
                bl      cache_off
                mov     r0, #0                  @ must be zero
                mov     r1, r7                  @ restore architecture number
                mov     r2, r8                  @ restore atags pointer
                mov     pc, r4                  @ call kernel

/*
 * Here follow the relocatable cache support functions for the
 * various processors.  This is a generic hook for locating an
 * entry and jumping to an instruction at the specified offset
 * from the start of the block.  Please note this is all position
 * independent code.
 *
 *  r1  = corrupted
 *  r2  = corrupted
 *  r3  = block offset
 *  r6  = corrupted
 *  r12 = corrupted
 */

call_cache_fn:  adr     r12, proc_types
#ifdef CONFIG_CPU_CP15
                mrc     p15, 0, r6, c0, c0      @ get processor ID
#else
                ldr     r6, =CONFIG_PROCESSOR_ID
#endif
1:              ldr     r1, [r12, #0]           @ get value
                ldr     r2, [r12, #4]           @ get mask
                eor     r1, r1, r6              @ (real ^ match)
                tst     r1, r2                  @       & mask
                addeq   pc, r12, r3             @ call cache function
                add     r12, r12, #4*5
                b       1b

/*
 * Table for cache operations.  This is basically:
 *   - CPU ID match
 *   - CPU ID mask
 *   - 'cache on' method instruction
 *   - 'cache off' method instruction
 *   - 'cache flush' method instruction
 *
 * We match an entry using: ((real_id ^ match) & mask) == 0
 *
 * Writethrough caches generally only need 'on' and 'off'
 * methods.  Writeback caches _must_ have the flush method
 * defined.
 */
                .type   proc_types,#object
proc_types:
                .word   0x41560600              @ ARM6/610
                .word   0xffffffe0
                b       __arm6_mmu_cache_off    @ works, but slow
                b       __arm6_mmu_cache_off
                mov     pc, lr
@               b       __arm6_mmu_cache_on             @ untested
@               b       __arm6_mmu_cache_off
@               b       __armv3_mmu_cache_flush

                .word   0x00000000              @ old ARM ID
                .word   0x0000f000
                mov     pc, lr
                mov     pc, lr
                mov     pc, lr

                .word   0x41007000              @ ARM7/710
                .word   0xfff8fe00
                b       __arm7_mmu_cache_off
                b       __arm7_mmu_cache_off
                mov     pc, lr

                .word   0x41807200              @ ARM720T (writethrough)
                .word   0xffffff00
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                mov     pc, lr

                .word   0x41007400              @ ARM74x
                .word   0xff00ff00
                b       __armv3_mpu_cache_on
                b       __armv3_mpu_cache_off
                b       __armv3_mpu_cache_flush
                
                .word   0x41009400              @ ARM94x
                .word   0xff00ff00
                b       __armv4_mpu_cache_on
                b       __armv4_mpu_cache_off
                b       __armv4_mpu_cache_flush

                .word   0x00007000              @ ARM7 IDs
                .word   0x0000f000
                mov     pc, lr
                mov     pc, lr
                mov     pc, lr

                @ Everything from here on will be the new ID system.

                .word   0x4401a100              @ sa110 / sa1100
                .word   0xffffffe0
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv4_mmu_cache_flush

                .word   0x6901b110              @ sa1110
                .word   0xfffffff0
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv4_mmu_cache_flush

                @ These match on the architecture ID

                .word   0x00020000              @ ARMv4T
                .word   0x000f0000
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv4_mmu_cache_flush

                .word   0x00050000              @ ARMv5TE
                .word   0x000f0000
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv4_mmu_cache_flush

                .word   0x00060000              @ ARMv5TEJ
                .word   0x000f0000
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv4_mmu_cache_flush

                .word   0x0007b000              @ ARMv6
                .word   0x000ff000
                b       __armv4_mmu_cache_on
                b       __armv4_mmu_cache_off
                b       __armv6_mmu_cache_flush

                .word   0x000f0000              @ new CPU Id
                .word   0x000f0000
                b       __armv7_mmu_cache_on
                b       __armv7_mmu_cache_off
                b       __armv7_mmu_cache_flush

                .word   0                       @ unrecognised type
                .word   0
                mov     pc, lr
                mov     pc, lr
                mov     pc, lr

                .size   proc_types, . - proc_types

/*
 * Turn off the Cache and MMU.  ARMv3 does not support
 * reading the control register, but ARMv4 does.
 *
 * On entry,  r6 = processor ID
 * On exit,   r0, r1, r2, r3, r12 corrupted
 * This routine must preserve: r4, r6, r7
 */
                .align  5
cache_off:      mov     r3, #12                 @ cache_off function
                b       call_cache_fn

__armv4_mpu_cache_off:
                mrc     p15, 0, r0, c1, c0
                bic     r0, r0, #0x000d
                mcr     p15, 0, r0, c1, c0      @ turn MPU and cache off
                mov     r0, #0
                mcr     p15, 0, r0, c7, c10, 4  @ drain write buffer
                mcr     p15, 0, r0, c7, c6, 0   @ flush D-Cache
                mcr     p15, 0, r0, c7, c5, 0   @ flush I-Cache
                mov     pc, lr

__armv3_mpu_cache_off:
                mrc     p15, 0, r0, c1, c0
                bic     r0, r0, #0x000d
                mcr     p15, 0, r0, c1, c0, 0   @ turn MPU and cache off
                mov     r0, #0
                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mov     pc, lr

__armv4_mmu_cache_off:
                mrc     p15, 0, r0, c1, c0
                bic     r0, r0, #0x000d
                mcr     p15, 0, r0, c1, c0      @ turn MMU and cache off
                mov     r0, #0
                mcr     p15, 0, r0, c7, c7      @ invalidate whole cache v4
                mcr     p15, 0, r0, c8, c7      @ invalidate whole TLB v4
                mov     pc, lr

__armv7_mmu_cache_off:
                mrc     p15, 0, r0, c1, c0
                bic     r0, r0, #0x000d
                mcr     p15, 0, r0, c1, c0      @ turn MMU and cache off
                mov     r12, lr
                bl      __armv7_mmu_cache_flush
                mov     r0, #0
                mcr     p15, 0, r0, c8, c7, 0   @ invalidate whole TLB
                mov     pc, r12

__arm6_mmu_cache_off:
                mov     r0, #0x00000030         @ ARM6 control reg.
                b       __armv3_mmu_cache_off

__arm7_mmu_cache_off:
                mov     r0, #0x00000070         @ ARM7 control reg.
                b       __armv3_mmu_cache_off

__armv3_mmu_cache_off:
                mcr     p15, 0, r0, c1, c0, 0   @ turn MMU and cache off
                mov     r0, #0
                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mcr     p15, 0, r0, c5, c0, 0   @ invalidate whole TLB v3
                mov     pc, lr

/*
 * Clean and flush the cache to maintain consistency.
 *
 * On entry,
 *  r6 = processor ID
 * On exit,
 *  r1, r2, r3, r11, r12 corrupted
 * This routine must preserve:
 *  r0, r4, r5, r6, r7
 */
                .align  5
cache_clean_flush:
                mov     r3, #16
                b       call_cache_fn

__armv4_mpu_cache_flush:
                mov     r2, #1
                mov     r3, #0
                mcr     p15, 0, ip, c7, c6, 0   @ invalidate D cache
                mov     r1, #7 << 5             @ 8 segments
1:              orr     r3, r1, #63 << 26       @ 64 entries
2:              mcr     p15, 0, r3, c7, c14, 2  @ clean & invalidate D index
                subs    r3, r3, #1 << 26
                bcs     2b                      @ entries 63 to 0
                subs    r1, r1, #1 << 5
                bcs     1b                      @ segments 7 to 0

                teq     r2, #0
                mcrne   p15, 0, ip, c7, c5, 0   @ invalidate I cache
                mcr     p15, 0, ip, c7, c10, 4  @ drain WB
                mov     pc, lr
                

__armv6_mmu_cache_flush:
                mov     r1, #0
                mcr     p15, 0, r1, c7, c14, 0  @ clean+invalidate D
                mcr     p15, 0, r1, c7, c5, 0   @ invalidate I+BTB
                mcr     p15, 0, r1, c7, c15, 0  @ clean+invalidate unified
                mcr     p15, 0, r1, c7, c10, 4  @ drain WB
                mov     pc, lr

__armv7_mmu_cache_flush:
                mrc     p15, 0, r10, c0, c1, 5  @ read ID_MMFR1
                tst     r10, #0xf << 16         @ hierarchical cache (ARMv7)
                beq     hierarchical
                mov     r10, #0
                mcr     p15, 0, r10, c7, c14, 0 @ clean+invalidate D
                b       iflush
hierarchical:
                stmfd   sp!, {r0-r5, r7, r9-r11}
                mrc     p15, 1, r0, c0, c0, 1   @ read clidr
                ands    r3, r0, #0x7000000      @ extract loc from clidr
                mov     r3, r3, lsr #23         @ left align loc bit field
                beq     finished                @ if loc is 0, then no need to 
clean
                mov     r10, #0                 @ start clean at cache level 0
loop1:
                add     r2, r10, r10, lsr #1    @ work out 3x current cache 
level
                mov     r1, r0, lsr r2          @ extract cache type bits from 
clidr
                and     r1, r1, #7              @ mask of the bits for current 
cache only
                cmp     r1, #2                  @ see what cache we have at 
this level
                blt     skip                    @ skip if no cache, or just 
i-cache
                mcr     p15, 2, r10, c0, c0, 0  @ select current cache level in 
cssr
                mcr     p15, 0, r10, c7, c5, 4  @ isb to sych the new cssr&csidr
                mrc     p15, 1, r1, c0, c0, 0   @ read the new csidr
                and     r2, r1, #7              @ extract the length of the 
cache lines
                add     r2, r2, #4              @ add 4 (line length offset)
                ldr     r4, =0x3ff
                ands    r4, r4, r1, lsr #3      @ find maximum number on the 
way size
                .word   0xe16f5f14              @ clz r5, r4 - find bit 
position of way size increment
                ldr     r7, =0x7fff
                ands    r7, r7, r1, lsr #13     @ extract max number of the 
index size
loop2:
                mov     r9, r4                  @ create working copy of max 
way size
loop3:
                orr     r11, r10, r9, lsl r5    @ factor way and cache number 
into r11
                orr     r11, r11, r7, lsl r2    @ factor index number into r11
                mcr     p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
                subs    r9, r9, #1              @ decrement the way
                bge     loop3
                subs    r7, r7, #1              @ decrement the index
                bge     loop2
skip:
                add     r10, r10, #2            @ increment cache number
                cmp     r3, r10
                bgt     loop1
finished:
                mov     r10, #0                 @ swith back to cache level 0
                mcr     p15, 2, r10, c0, c0, 0  @ select current cache level in 
cssr
                ldmfd   sp!, {r0-r5, r7, r9-r11}
iflush:
                mcr     p15, 0, r10, c7, c5, 0  @ invalidate I+BTB
                mcr     p15, 0, r10, c7, c10, 4 @ drain WB
                mov     pc, lr

__armv4_mmu_cache_flush:
                mov     r2, #64*1024            @ default: 32K dcache size (*2)
                mov     r11, #32                @ default: 32 byte line size
                mrc     p15, 0, r3, c0, c0, 1   @ read cache type
                teq     r3, r6                  @ cache ID register present?
                beq     no_cache_id
                mov     r1, r3, lsr #18
                and     r1, r1, #7
                mov     r2, #1024
                mov     r2, r2, lsl r1          @ base dcache size *2
                tst     r3, #1 << 14            @ test M bit
                addne   r2, r2, r2, lsr #1      @ +1/2 size if M == 1
                mov     r3, r3, lsr #12
                and     r3, r3, #3
                mov     r11, #8
                mov     r11, r11, lsl r3        @ cache line size in bytes
no_cache_id:
                bic     r1, pc, #63             @ align to longest cache line
                add     r2, r1, r2
1:              ldr     r3, [r1], r11           @ s/w flush D cache
                teq     r1, r2
                bne     1b

                mcr     p15, 0, r1, c7, c5, 0   @ flush I cache
                mcr     p15, 0, r1, c7, c6, 0   @ flush D cache
                mcr     p15, 0, r1, c7, c10, 4  @ drain WB
                mov     pc, lr

__armv3_mmu_cache_flush:
__armv3_mpu_cache_flush:
                mov     r1, #0
                mcr     p15, 0, r0, c7, c0, 0   @ invalidate whole cache v3
                mov     pc, lr

/*
 * Various debugging routines for printing hex characters and
 * memory, which again must be relocatable.
 */

#ifdef DEBUG
                .type   phexbuf,#object
phexbuf:        .space  12
                .size   phexbuf, . - phexbuf

phex:           adr     r3, phexbuf
                mov     r2, #0
                strb    r2, [r3, r1]
1:              subs    r1, r1, #1
                movmi   r0, r3
                bmi     puts
                and     r2, r0, #15
                mov     r0, r0, lsr #4
                cmp     r2, #10
                addge   r2, r2, #7
                add     r2, r2, #'0'
                strb    r2, [r3, r1]
                b       1b

puts:           loadsp  r3
1:              ldrb    r2, [r0], #1
                teq     r2, #0
                moveq   pc, lr
2:              writeb  r2, r3
                mov     r1, #0x00020000
3:              subs    r1, r1, #1
                bne     3b
                teq     r2, #'\n'
                moveq   r2, #'\r'
                beq     2b
                teq     r0, #0
                bne     1b
                mov     pc, lr
putc:
                mov     r2, r0
                mov     r0, #0
                loadsp  r3
                b       2b

memdump:        mov     r12, r0
                mov     r10, lr
                mov     r11, #0
2:              mov     r0, r11, lsl #2
                add     r0, r0, r12
                mov     r1, #8
                bl      phex
                mov     r0, #':'
                bl      putc
1:              mov     r0, #' '
                bl      putc
                ldr     r0, [r12, r11, lsl #2]
                mov     r1, #8
                bl      phex
                and     r0, r11, #7
                teq     r0, #3
                moveq   r0, #' '
                bleq    putc
                and     r0, r11, #7
                add     r11, r11, #1
                teq     r0, #7
                bne     1b
                mov     r0, #'\n'
                bl      putc
                cmp     r11, #64
                blt     2b
                mov     pc, r10
#endif

                .ltorg
reloc_end:

                .align
                .section ".stack", "w"
user_stack:     .space  4096
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