arch/ppc/boot/openfirmware/coffmain.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 <asm/processor.h>
  11 #include <asm/page.h>
  12
  13 #include "nonstdio.h"
  14 #include "of1275.h"
  15
  16 /* Passed from the linker */
  17 extern char __image_begin, __image_end;
  18 extern char __ramdisk_begin[], __ramdisk_end;
  19 extern char _start, _end;
  20
  21 extern char image_data[], initrd_data[];
  22 extern int initrd_len, image_len;
  23 extern unsigned int heap_max;
  24 extern void flush_cache(void *start, unsigned int len);
  25 extern void gunzip(void *, int, unsigned char *, int *);
  26 extern void make_bi_recs(unsigned long addr, char *name, unsigned int mach,
  27                 unsigned int progend);
  28 extern void setup_bats(unsigned long start);
  29
  30 char *avail_ram;
  31 char *begin_avail, *end_avail;
  32 char *avail_high;
  33
  34 #define SCRATCH_SIZE    (128 << 10)
  35
  36 static char heap[SCRATCH_SIZE];
  37
  38 static unsigned long ram_start = 0;
  39 static unsigned long ram_end = 0x1000000;
  40
  41 static unsigned long prog_start = 0x900000;
  42 static unsigned long prog_size = 0x700000;
  43
  44 typedef void (*kernel_start_t)(int, int, void *);
  45
  46 void boot(int a1, int a2, void *prom)
  47 {
  48     unsigned sa, len;
  49     void *dst;
  50     unsigned char *im;
  51     unsigned initrd_start, initrd_size;
  52
  53     printf("coffboot starting: loaded at 0x%p\n", &_start);
  54     setup_bats(ram_start);
  55
  56     initrd_size = (char *)(&__ramdisk_end) - (char *)(&__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, (char *)(&__ramdisk_begin), initrd_size);
  64         memcpy((char *)initrd_start, (char *)(&__ramdisk_begin), initrd_size);
  65         prog_size = initrd_start - prog_start;
  66     } else
  67         a2 = 0xdeadbeef;
  68
  69     im = (char *)(&__image_begin);
  70     len = (char *)(&__image_end) - (char *)(&__image_begin);
  71     /* claim 4MB starting at PROG_START */
  72     claim(prog_start, prog_size, 0);
  73     map(prog_start, prog_start, prog_size);
  74     dst = (void *) prog_start;
  75     if (im[0] == 0x1f && im[1] == 0x8b) {
  76         /* set up scratch space */
  77         begin_avail = avail_high = avail_ram = heap;
  78         end_avail = heap + sizeof(heap);
  79         printf("heap at 0x%p\n", avail_ram);
  80         printf("gunzipping (0x%p <- 0x%p:0x%p)...", dst, im, im+len);
  81         gunzip(dst, prog_size, im, &len);
  82         printf("done %u bytes\n", len);
  83         printf("%u bytes of heap consumed, max in use %u\n",
  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), "coffboot", _MACH_Pmac,
  91                     (prog_start + prog_size));
  92
  93     sa = (unsigned long)prog_start;
  94     printf("start address = 0x%x\n", sa);
  95
  96     (*(kernel_start_t)sa)(a1, a2, prom);
  97
  98     printf("returned?\n");
  99
 100     pause();
 101 }