payloads/libpayload/arch/x86/multiboot.c

   1 /*
   2  *
   3  * Copyright (C) 2008 Advanced Micro Devices, Inc.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <libpayload-config.h>
  30 #include <libpayload.h>
  31 #include <multiboot_tables.h>
  32
  33 unsigned long loader_eax;  /* The value of EAX passed from the loader */
  34 unsigned long loader_ebx;  /* The value of EBX passed from the loader */
  35
  36 static int mb_add_memrange(struct sysinfo_t *info, unsigned long long base,
  37                            unsigned long long size, unsigned int type)
  38 {
  39         if (info->n_memranges >= SYSINFO_MAX_MEM_RANGES)
  40                 return -1;
  41
  42 #if CONFIG(LP_MEMMAP_RAM_ONLY)
  43         /* 1 == normal RAM.  Ignore everything else for now */
  44         if (type != 1)
  45                 return 0;
  46 #endif
  47
  48         info->memrange[info->n_memranges].base = base;
  49         info->memrange[info->n_memranges].size = size;
  50         info->memrange[info->n_memranges].type = type;
  51         info->n_memranges++;
  52
  53         return 0;
  54 }
  55
  56 static void mb_parse_mmap(struct multiboot_header *table,
  57                           struct sysinfo_t *info)
  58 {
  59         u8 *start = (u8 *) phys_to_virt(table->mmap_addr);
  60         u8 *ptr = start;
  61
  62         info->n_memranges = 0;
  63
  64         while(ptr < (start + table->mmap_length)) {
  65                 struct multiboot_mmap *mmap = (struct multiboot_mmap *) ptr;
  66
  67                 if (mb_add_memrange(info, mmap->addr, mmap->length, mmap->type))
  68                         return;
  69
  70                 ptr += (mmap->size + sizeof(mmap->size));
  71         }
  72 }
  73
  74 static void mb_parse_meminfo(struct multiboot_header *table,
  75                              struct sysinfo_t *info)
  76 {
  77         unsigned long long mem_low = table->mem_lower;
  78         unsigned long long mem_high = table->mem_higher;
  79
  80         info->n_memranges = 0;
  81
  82         if (mem_low)
  83                 mb_add_memrange(info, 0 * MiB, mem_low * KiB, 1);
  84
  85         if (mem_high)
  86                 mb_add_memrange(info, 1 * MiB, mem_high * KiB, 1);
  87 }
  88
  89 static void mb_parse_cmdline(struct multiboot_header *table)
  90 {
  91         extern int main_argc;
  92         extern char *main_argv[];
  93         char *c = phys_to_virt(table->cmdline);
  94
  95         while(*c != '\0' && main_argc < MAX_ARGC_COUNT) {
  96                 main_argv[main_argc++] = c;
  97
  98                 for( ; *c != '\0' && !isspace(*c); c++);
  99
 100                 if (*c) {
 101                         *c = 0;
 102                         c++;
 103                 }
 104         }
 105 }
 106
 107 int get_multiboot_info(struct sysinfo_t *info)
 108 {
 109         struct multiboot_header *table;
 110
 111         if (loader_eax != MULTIBOOT_MAGIC)
 112                 return -1;
 113
 114         table = (struct multiboot_header *) phys_to_virt(loader_ebx);
 115
 116         info->mbtable = phys_to_virt(loader_ebx);
 117
 118         if (table->flags & MULTIBOOT_FLAGS_MMAP)
 119                 mb_parse_mmap(table, info);
 120         else if (table->flags & MULTIBOOT_FLAGS_MEMINFO)
 121                 mb_parse_meminfo(table, info);
 122
 123         if (table->flags & MULTIBOOT_FLAGS_CMDLINE)
 124                 mb_parse_cmdline(table);
 125
 126         return 0;
 127 }