arch/ppc/boot/openfirmware/chrpmain.c

   1 /*
   2  * Copyright (C) Paul Mackerras 1997.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9 #include <linux/string.h>
  10 #include "nonstdio.h"
  11 #include "of1275.h"
  12 #include <asm/processor.h>
  13 #include <asm/page.h>
  14
  15 /* Passed from the linker */
  16 extern char __image_begin, __image_end;
  17 extern char __ramdisk_begin, __ramdisk_end;
  18 extern char _start, _end;
  19
  20 extern unsigned int heap_max;
  21 extern void flush_cache(void *, unsigned long);
  22 extern void gunzip(void *, int, unsigned char *, int *);
  23 extern void make_bi_recs(unsigned long addr, char *name, unsigned int mach,
  24                 unsigned int progend);
  25
  26 char *avail_ram;
  27 char *begin_avail, *end_avail;
  28 char *avail_high;
  29
  30 #define RAM_START       0x00000000
  31 #define RAM_END         (64<<20)
  32
  33 #define BOOT_START      ((unsigned long)_start)
  34 #define BOOT_END        ((unsigned long)(_end + 0xFFF) & ~0xFFF)
  35
  36 #define RAM_FREE        ((unsigned long)(_end+0x1000)&~0xFFF)
  37 #define PROG_START      0x00010000
  38 #define PROG_SIZE       0x007f0000 /* 8MB */
  39
  40 #define SCRATCH_SIZE    (128 << 10)
  41
  42 static char scratch[SCRATCH_SIZE];      /* 1MB of scratch space for gunzip */
  43
  44 typedef void (*kernel_start_t)(int, int, void *, unsigned int, unsigned int);
  45
  46 void
  47 boot(int a1, int a2, void *prom)
  48 {
  49     unsigned sa, len;
  50     void *dst;
  51     unsigned char *im;
  52     unsigned int initrd_size, initrd_start;
  53
  54     printf("chrpboot starting: loaded at 0x%p\n\r", &_start);
  55
  56     initrd_size = &__ramdisk_end - &__ramdisk_begin;
  57     if (initrd_size) {
  58         initrd_start = (RAM_END - initrd_size) & ~0xFFF;
  59         a1 = initrd_start;
  60         a2 = initrd_size;
  61         claim(initrd_start, RAM_END - initrd_start, 0);
  62         printf("initial ramdisk moving 0x%x <- 0x%p (%x bytes)\n\r",
  63                initrd_start, &__ramdisk_begin, initrd_size);
  64         memcpy((char *)initrd_start, &__ramdisk_begin, initrd_size);
  65     } else {
  66         initrd_start = 0;
  67         initrd_size = 0;
  68         a2 = 0xdeadbeef;
  69     }
  70
  71     im = &__image_begin;
  72     len = &__image_end - &__image_begin;
  73     /* claim 4MB starting at PROG_START */
  74     claim(PROG_START, PROG_SIZE - PROG_START, 0);
  75     dst = (void *) PROG_START;
  76     if (im[0] == 0x1f && im[1] == 0x8b) {
  77         avail_ram = scratch;
  78         begin_avail = avail_high = avail_ram;
  79         end_avail = scratch + sizeof(scratch);
  80         printf("gunzipping (0x%p <- 0x%p:0x%p)...", dst, im, im+len);
  81         gunzip(dst, 0x400000, im, &len);
  82         printf("done %u bytes\n\r", len);
  83         printf("%u bytes of heap consumed, max in use %u\n\r",
  84                avail_high - begin_avail, heap_max);
  85     } else {
  86         memmove(dst, im, len);
  87     }
  88
  89     flush_cache(dst, len);
  90     make_bi_recs(((unsigned long) dst + len), "chrpboot", _MACH_chrp,
  91                     (PROG_START + PROG_SIZE));
  92
  93     sa = PROG_START;
  94     printf("start address = 0x%x\n\r", sa);
  95
  96     (*(kernel_start_t)sa)(a1, a2, prom, initrd_start, initrd_size);
  97
  98     printf("returned?\n\r");
  99
 100     pause();
 101 }