LXR linux/arch/sh/boot/compressed/head

   1/*
   2 *  linux/arch/sh/boot/compressed/head.S
   3 *
   4 *  Copyright (C) 1999 Stuart Menefy
   5 *  Copyright (C) 2003 SUGIOKA Toshinobu
   6 */
   7
   8.text
   9
  10#include <asm/page.h>
  11
  12        .global startup
  13startup:
  14        /* Load initial status register */
  15        mov.l   init_sr, r1
  16        ldc     r1, sr
  17
  18        /* Move myself to proper location if necessary */
  19        mova    1f, r0
  20        mov.l   1f, r2
  21        cmp/eq  r2, r0
  22        bt      clear_bss
  23        sub     r0, r2
  24        mov.l   bss_start_addr, r0
  25        mov     #0xffffffe0, r1
  26        and     r1, r0                  ! align cache line
  27        mov.l   text_start_addr, r3
  28        mov     r0, r1
  29        sub     r2, r1
  303:
  31        mov.l   @r1, r4
  32        mov.l   @(4,r1), r5
  33        mov.l   @(8,r1), r6
  34        mov.l   @(12,r1), r7
  35        mov.l   @(16,r1), r8
  36        mov.l   @(20,r1), r9
  37        mov.l   @(24,r1), r10
  38        mov.l   @(28,r1), r11
  39        mov.l   r4, @r0
  40        mov.l   r5, @(4,r0)
  41        mov.l   r6, @(8,r0)
  42        mov.l   r7, @(12,r0)
  43        mov.l   r8, @(16,r0)
  44        mov.l   r9, @(20,r0)
  45        mov.l   r10, @(24,r0)
  46        mov.l   r11, @(28,r0)
  47#ifdef CONFIG_CPU_SH4
  48        ocbwb   @r0
  49#endif
  50        cmp/hi  r3, r0
  51        add     #-32, r0
  52        bt/s    3b
  53         add    #-32, r1
  54        mov.l   2f, r0
  55        jmp     @r0
  56         nop
  57
  58        .align 2
  591:      .long   1b
  602:      .long   clear_bss
  61text_start_addr:
  62        .long   startup
  63
  64        /* Clear BSS */
  65clear_bss:
  66        mov.l   end_addr, r1
  67        mov.l   bss_start_addr, r2
  68        mov     #0, r0
  69l1:
  70        mov.l   r0, @-r1
  71        cmp/eq  r1,r2
  72        bf      l1
  73
  74        /* Set the initial pointer. */
  75        mov.l   init_stack_addr, r0
  76        mov.l   @r0, r15
  77
  78        /* Decompress the kernel */
  79        mov.l   decompress_kernel_addr, r0
  80        jsr     @r0
  81        nop
  82
  83        /* Jump to the start of the decompressed kernel */
  84        mov.l   kernel_start_addr, r0
  85        jmp     @r0
  86        nop
  87        
  88        .align  2
  89bss_start_addr:
  90        .long   __bss_start
  91end_addr:
  92        .long   _end
  93init_sr:
  94        .long   0x500000F0      /* Privileged mode, Bank=0, Block=1, IMASK=0xF */
  95kexec_magic:
  96        .long   0x400000F0      /* magic used by kexec to parse zImage format */
  97init_stack_addr:
  98        .long   stack_start
  99decompress_kernel_addr:
 100        .long   decompress_kernel
 101kernel_start_addr:
 102#ifdef CONFIG_32BIT
 103        .long   ___pa(_text+PAGE_SIZE)
 104#else
 105        .long   _text+PAGE_SIZE
 106#endif
 107
 108        .align  9
 109fake_headers_as_bzImage:
 110        .word   0
 111        .ascii  "HdrS"          ! header signature
 112        .word   0x0202          ! header version number (>= 0x0105)
 113                                ! or else old loadlin-1.5 will fail)
 114        .word   0               ! default_switch
 115        .word   0               ! SETUPSEG
 116        .word   0x1000
 117        .word   0               ! pointing to kernel version string
 118        .byte   0               ! = 0, old one (LILO, Loadlin,
 119                                ! 0xTV: T=0 for LILO
 120                                !       V = version
 121        .byte   1               ! Load flags bzImage=1
 122        .word   0x8000          ! size to move, when setup is not
 123        .long   0x100000        ! 0x100000 = default for big kernel
 124        .long   0               ! address of loaded ramdisk image
 125        .long   0               # its size in bytes
 126