arm-linux head.s 分析 基于mini2440 uboot后的解压过程

/*
 *  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.
 */


#define DEBUG 23453
#undef  DEBUG


#ifdef DEBUG




#if defined(CONFIG_DEBUG_ICEDCC)
fff
#ifdef CONFIG_CPU_V6
.macro loadsp, rb
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c0, c5, 0
.endm
#elif defined(CONFIG_CPU_XSCALE)
.macro loadsp, rb
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c8, c0, 0
.endm
#else
.macro loadsp, rb
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c1, c0, 0
.endm
#endif


#else
//eee
#include <mach/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


//启动参数的首地址通过r2传递 r0-->0 r1-->机器号 机器id
        //uboot的bootm提交cpu权限之前 要设置好r0,r1,r2寄存器,然后cpu权限赋给了内核
        //首先保存机器号与启动参数地址指针,因为后面会用到r1,r2
        //kphex sp, 8
//kputc #'\n'
//kphex r15, 8
//kputc #'\n'


#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
 //ARM( swi 0x123456 ) @ angel_SWI_ARM
 //THUMB( svc 0xab ) @ angel_SWI_THUMB
 //没有jtag调试器
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
        //获取LC0的绝对运行地址 与pc相关 pc加偏移
        //ARM( ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp} )


ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp}


        //THUMB( ldmia r0, {r1, r2, r3, r4, r5, r6, ip} )
        //THUMB( ldr sp, [r0, #28] )
        
        subs r0, r0, r1
        //r1 LC0的相对地址 与pc无关 即与位置无关 由编译器决定
        //计算其与绝对地址的偏移
        @ calculate the delta offset
        //30008040
        //kphex sp, 8
//kputc #'\n'

beq not_relocated
   //if delta is zero, we are running at the address we
   //were linked at.
        //不是 现在delta是30008040
/*
* 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


//kphex sp, 8
//kputc #'\n'
        
        #if 0
stmfd sp!, {r0 - r12, r14}
        adr r0,str_p1
bl puts
ldmfd sp!, {r0 - r12, r14}
#endif









/*
* Relocate all entries in the GOT table.
*/


        //ldr r1, [r6, #0]
//add r1, r1, r0
        //kphex r1, 8
//kputc #'\n'


        //stmfd   sp!, {r0 - r12, r14}
        //kphex r2, 8
//3025A754
//kputc   #'\n'
//ldmfd sp!, {r0 - r12, r14}


1: ldr r1, [r6, #0]
add r1, r1, r0
str r1, [r6], #4
cmp r6, ip
blo 1b
//relocate entries in the GOT table.  
//This fixes up the C references.
//重新定位 全局变量区 已初始化的全局变量 data段
//全局变量的地址要重新定位 即都加一个偏移30008040
//由于got表中的入口项描述符所描述的是各全局变量相对于0地址的偏移量,
//而我们的加载运行地址是30008040
#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
        //bss段清零 无需复制 只需知道起始地址与长度即可
        //未初始化的全局变量
        
/*
* The C runtime environment should now be setup
* sufficiently.  Turn the cache on, set up some
* pointers, and start decompressing.
*/
//至此,C运行环境已经完全建立起来了.
//打开cache,设置一些相关的指针,然后开始解压压缩内核
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)
     malloc区的上方,存放解压后的内核
     
 * We basically want:
 *   r4 >= r2 -> OK
 *   r4 + image length <= r5 -> OK
 */   


/*
 .align  2
 .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
 


  r2 解压后的内核  
  malloc 64k
  sp 堆栈4k bss段的结尾即_end r3
  __bss_start bss段 r2
  data 
  .got.plt
---------------------------------------------------|
  _got_end  ip                                     |
___________________________________________________|  
  _got_start r6
  rodata
  piggydata 
  head.s gzip.c
  _start  r5
*/


        #if 0
stmfd   sp!, {r0 - r12, r14}
        kphex r2, 8
//3025A754
kputc   #'\n'
ldmfd sp!, {r0 - r12, r14}
#endif



//r4-->30008000
//r4 = final kernel address
//解压后内核的运行地址


           
//r5-->30008040
//r5 = start of this image
//本执行映像的起始地址
            
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-r12,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 - r12, r14} @ copy relocation code
stmia r1!, {r9 - r12, r14}
ldmia r2!, {r9 - r12, r14}
stmia r1!, {r9 - r12, r14}
cmp r2, r3
blo 1b
mov sp, r1
add sp, sp, #128 @ relocate the stack


bl cache_clean_flush
 ARM( add pc, r5, r0 ) @ call relocation code
 THUMB( add r12, r5, r0 )
 THUMB( mov pc, r12 ) @ 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


.align 2
.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


#if 1
ENTRY(printascii)

b 2f
1:
       kputc r1
//teq r1, #'\n'
//moveq r1, #'\r'
//beq 1b
2: teq r0, #0
ldrneb r1, [r0], #1
teqne r1, #0
bne 1b
mov pc, lr
ENDPROC(printascii)


str_p1: .asciz "\nin arch/arm/boot/compressed/head.s\n"
str_p2: .asciz ").\n"
.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
ENDPROC(__setup_mmu)


__armv4_mmu_cache_on:
mov r12, lr
#ifdef CONFIG_MMU
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
#ifdef CONFIG_CPU_ENDIAN_BE8
orr r0, r0, #1 << 25 @ big-endian page tables
#endif
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
#endif
mov pc, r12


__armv7_mmu_cache_on:
mov r12, lr
#ifdef CONFIG_MMU
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
#endif
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
#ifdef CONFIG_MMU
#ifdef CONFIG_CPU_ENDIAN_BE8
orr r0, r0, #1 << 25 @ big-endian page tables
#endif
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
#endif
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


__fa526_cache_on:
mov r12, lr
bl __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 @ Invalidate whole cache
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
mrc p15, 0, r0, c1, c0, 0 @ read control reg
orr r0, r0, #0x1000 @ I-cache enable
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
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 CONFIG_THUMB2_KERNEL
#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
#endif


/*
 * 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-r12,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 - r12, r14} @ relocate kernel
stmia r1!, {r0, r2, r3, r10 - r12, r14}
.endr
//解压后的内核重新加载到 30008000
//由于会加载到本代码的地方,所以本代码提前搬运到其他地方,再执行本代码
        //自身就不会被覆盖 
cmp r5, r9
blo 1b
mov sp, r1
add sp, sp, #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
//跳到30008000地址,执行解压缩后的内核-->  :-) 
//这部分代码还是挺有技巧的,gzip解压的细节过程没有看明白,只知道解压了,
//解压到什么地方等.
                                                            
/*
 * 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
 ARM( addeq pc, r12, r3 ) @ call cache function
 THUMB( addeq r12, r3 )
 THUMB( moveq pc, r12 ) @ 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.
 */
.align 2
.type proc_types,#object
proc_types:
.word 0x41560600 @ ARM6/610
.word 0xffffffe0
W(b) __arm6_mmu_cache_off @ works, but slow
W(b) __arm6_mmu_cache_off
mov pc, lr
 THUMB( nop )
@ 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
 THUMB( nop )
mov pc, lr
 THUMB( nop )
mov pc, lr
 THUMB( nop )


.word 0x41007000 @ ARM7/710
.word 0xfff8fe00
W(b) __arm7_mmu_cache_off
W(b) __arm7_mmu_cache_off
mov pc, lr
 THUMB( nop )


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


.word 0x41007400 @ ARM74x
.word 0xff00ff00
W(b) __armv3_mpu_cache_on
W(b) __armv3_mpu_cache_off
W(b) __armv3_mpu_cache_flush

.word 0x41009400 @ ARM94x
.word 0xff00ff00
W(b) __armv4_mpu_cache_on
W(b) __armv4_mpu_cache_off
W(b) __armv4_mpu_cache_flush


.word 0x00007000 @ ARM7 IDs
.word 0x0000f000
mov pc, lr
 THUMB( nop )
mov pc, lr
 THUMB( nop )
mov pc, lr
 THUMB( nop )


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


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


.word 0x6901b110 @ sa1110
.word 0xfffffff0
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x56056930
.word 0xff0ffff0 @ PXA935
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x56158000 @ PXA168
.word 0xfffff000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv5tej_mmu_cache_flush


.word 0x56056930
.word 0xff0ffff0 @ PXA935
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x56050000 @ Feroceon
.word 0xff0f0000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv5tej_mmu_cache_flush


#ifdef CONFIG_CPU_FEROCEON_OLD_ID
/* this conflicts with the standard ARMv5TE entry */
.long 0x41009260 @ Old Feroceon
.long 0xff00fff0
b __armv4_mmu_cache_on
b __armv4_mmu_cache_off
b __armv5tej_mmu_cache_flush
#endif


.word 0x66015261 @ FA526
.word 0xff01fff1
W(b) __fa526_cache_on
W(b) __armv4_mmu_cache_off
W(b) __fa526_cache_flush


@ These match on the architecture ID


.word 0x00020000 @ ARMv4T
.word 0x000f0000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x00050000 @ ARMv5TE
.word 0x000f0000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x00060000 @ ARMv5TEJ
.word 0x000f0000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv4_mmu_cache_flush


.word 0x0007b000 @ ARMv6
.word 0x000ff000
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv6_mmu_cache_flush


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


.word 0 @ unrecognised type
.word 0
mov pc, lr
 THUMB( nop )
mov pc, lr
 THUMB( nop )
mov pc, lr
 THUMB( nop )


.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:
#ifdef CONFIG_MMU
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
#endif
mov pc, lr


__armv7_mmu_cache_off:
mrc p15, 0, r0, c1, c0
#ifdef CONFIG_MMU
bic r0, r0, #0x000d
#else
bic r0, r0, #0x000c
#endif
mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
mov r12, lr
bl __armv7_mmu_cache_flush
mov r0, #0
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7, 0 @ invalidate whole TLB
#endif
mcr p15, 0, r0, c7, c5, 6 @ invalidate BTC
mcr p15, 0, r0, c7, c10, 4 @ DSB
mcr p15, 0, r0, c7, c5, 4 @ ISB
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

__fa526_cache_flush:
mov r1, #0
mcr p15, 0, r1, c7, c14, 0 @ clean and invalidate D cache
mcr p15, 0, r1, c7, c5, 0 @ flush I cache
mcr p15, 0, r1, 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)
mov r10, #0
beq hierarchical
mcr p15, 0, r10, c7, c14, 0 @ clean+invalidate D
b iflush
hierarchical:
mcr p15, 0, r10, c7, c10, 5 @ DMB
stmfd sp!, {r0-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
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:
 ARM( orr r11, r10, r9, lsl r5 ) @ factor way and cache number into r11
 ARM( orr r11, r11, r7, lsl r2 ) @ factor index number into r11
 THUMB( lsl r6, r9, r5 )
 THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11
 THUMB( lsl r6, r7, r2 )
 THUMB( orr r11, r11, r6 ) @ 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:
ldmfd sp!, {r0-r7, r9-r11}
mov r10, #0 @ swith back to cache level 0
mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
iflush:
mcr p15, 0, r10, c7, c10, 4 @ DSB
mcr p15, 0, r10, c7, c5, 0 @ invalidate I+BTB
mcr p15, 0, r10, c7, c10, 4 @ DSB
mcr p15, 0, r10, c7, c5, 4 @ ISB
mov pc, lr


__armv5tej_mmu_cache_flush:
1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate D cache
bne 1b
mcr p15, 0, r0, c7, c5, 0 @ flush I cache
mcr p15, 0, r0, 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:
mov r1, pc
bic r1, r1, #63 @ align to longest cache line
add r2, r1, r2
1:
 ARM( ldr r3, [r1], r11 ) @ s/w flush D cache
 THUMB( ldr     r3, [r1] ) @ s/w flush D cache
 THUMB( add     r1, r1, r11 )
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
.align 2
.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