include/asm-i386/mach-default/setup_arch_post.h

   1 /**
   2  * machine_specific_memory_setup - Hook for machine specific memory setup.
   3  *
   4  * Description:
   5  *      This is included late in kernel/setup.c so that it can make
   6  *      use of all of the static functions.
   7  **/
   8
   9 static char * __init machine_specific_memory_setup(void)
  10 {
  11         char *who;
  12
  13
  14         who = "BIOS-e820";
  15
  16         /*
  17          * Try to copy the BIOS-supplied E820-map.
  18          *
  19          * Otherwise fake a memory map; one section from 0k->640k,
  20          * the next section from 1mb->appropriate_mem_k
  21          */
  22         sanitize_e820_map(E820_MAP, &E820_MAP_NR);
  23         if (copy_e820_map(E820_MAP, E820_MAP_NR) < 0) {
  24                 unsigned long mem_size;
  25
  26                 /* compare results from other methods and take the greater */
  27                 if (ALT_MEM_K < EXT_MEM_K) {
  28                         mem_size = EXT_MEM_K;
  29                         who = "BIOS-88";
  30                 } else {
  31                         mem_size = ALT_MEM_K;
  32                         who = "BIOS-e801";
  33                 }
  34
  35                 e820.nr_map = 0;
  36                 add_memory_region(0, LOWMEMSIZE(), E820_RAM);
  37                 add_memory_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
  38         }
  39         return who;
  40 }