LXR linux/arch/parisc/boot/compressed/head.S

   1/*
   2 * Startup glue code to uncompress the kernel
   3 *
   4 *   (C) 2017 Helge Deller <deller@gmx.de>
   5 */
   6
   7#include <linux/init.h>
   8#include <linux/linkage.h>
   9#include <asm/asm-offsets.h>
  10#include <asm/page.h>
  11#include <asm/psw.h>
  12#include <asm/pdc.h>
  13#include <asm/assembly.h>
  14#include "sizes.h"
  15
  16#define BOOTADDR(x)     (x)
  17
  18#ifndef CONFIG_64BIT
  19        .import $global$                /* forward declaration */
  20#endif /*!CONFIG_64BIT*/
  21
  22        __HEAD
  23
  24ENTRY(startup)
  25         .level LEVEL
  26
  27#define PSW_W_SM        0x200
  28#define PSW_W_BIT       36
  29
  30        ;! nuke the W bit, saving original value
  31        .level 2.0
  32        rsm     PSW_W_SM, %r1
  33
  34        .level 1.1
  35        extrw,u %r1, PSW_W_BIT-32, 1, %r1
  36        copy    %r1, %arg0
  37
  38        /* Make sure sr4-sr7 are set to zero for the kernel address space */
  39        mtsp    %r0,%sr4
  40        mtsp    %r0,%sr5
  41        mtsp    %r0,%sr6
  42        mtsp    %r0,%sr7
  43
  44        /* Clear BSS */
  45
  46        .import _bss,data
  47        .import _ebss,data
  48
  49        load32  BOOTADDR(_bss),%r3
  50        load32  BOOTADDR(_ebss),%r4
  51        ldo     FRAME_SIZE(%r4),%sp     /* stack at end of bss */
  52$bss_loop:
  53        cmpb,<<,n %r3,%r4,$bss_loop
  54        stw,ma  %r0,4(%r3)
  55
  56        /* Initialize the global data pointer */
  57        loadgp
  58
  59        /* arg0..arg4 were set by palo. */
  60        copy    %arg1, %r6              /* command line */
  61        copy    %arg2, %r7              /* rd-start */
  62        copy    %arg3, %r8              /* rd-end */
  63        load32  BOOTADDR(decompress_kernel),%r3
  64
  65#ifdef CONFIG_64BIT
  66        .level LEVEL
  67        ssm     PSW_W_SM, %r0           /* set W-bit */
  68        depdi   0, 31, 32, %r3
  69#endif
  70        load32  BOOTADDR(startup_continue), %r2
  71        bv,n    0(%r3)
  72
  73startup_continue:
  74#ifdef CONFIG_64BIT
  75        .level LEVEL
  76        rsm     PSW_W_SM, %r0           /* clear W-bit */
  77#endif
  78
  79        load32  KERNEL_BINARY_TEXT_START, %arg0 /* free mem */
  80        copy    %r6, %arg1              /* command line */
  81        copy    %r7, %arg2              /* rd-start */
  82        copy    %r8, %arg3              /* rd-end */
  83
  84        bv,n    0(%ret0)
  85END(startup)
  86