kernel/arch/x64/multiboot.cc

   1 // arch/x64/multiboot.cc -- Code to interpret multiboot data and initialize
   2 //                          free memory regions based thereupon.
   3 //
   4 // This software is copyright (c) 2006 Scott Wood <scott@buserror.net>.
   5 //
   6 // Permission is hereby granted, free of charge, to any person obtaining a copy of
   7 // this software and associated documentation files (the "Software"), to deal with
   8 // the Software without restriction, including without limitation the rights to
   9 // use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  10 // of the Software, and to permit persons to whom the Software is furnished to do
  11 // so, subject to the following condition:
  12 //
  13 // The above copyright notice and this permission notice shall be
  14 // included in all copies or substantial portions of the Software.
  15 //
  16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
  18 // FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  19 // CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
  22 // SOFTWARE.
  23
  24 #include <kern/libc.h>
  25 #include <kern/pagealloc.h>
  26
  27 #include <arch/multiboot.h>
  28 #include <arch/addrs.h>
  29 #include <arch/paging.h>
  30 #include <arch/mem.h>
  31
  32 #include <limits.h>
  33
  34 u32 x64_boot_info_phys;
  35
  36 namespace Arch {
  37 namespace Priv {
  38 namespace MultiBoot {
  39         BootInfo *boot_info;
  40
  41         void parse_mmap()
  42         {
  43         }
  44
  45         void make_mem_avail(uintptr_t page_start, uintptr_t page_end)
  46         {
  47                 using Mem::pages;
  48
  49                 if (page_start < dma32zonestart) {
  50                         size_t len;
  51
  52                         if (page_end <= dma32zonestart)
  53                                 len = page_end - page_start;
  54                         else
  55                                 len = dma32zonestart - page_start;
  56
  57                         isadmazone.free(&pages[page_start], len);
  58                         page_start = dma32zonestart;
  59                 }
  60
  61                 if (page_start < highzonestart && page_end > dma32zonestart) {
  62                         size_t len;
  63
  64                         if (page_end <= highzonestart)
  65                                 len = page_end - page_start;
  66                         else
  67                                 len = highzonestart - page_start;
  68
  69                         dma32zone.free(&pages[page_start], len);
  70                         page_start = highzonestart;
  71                 }
  72
  73                 if (page_end > highzonestart)
  74                         dma32zone.free(&pages[page_start], page_end - highzonestart);
  75         }
  76
  77         void process_info()
  78         {
  79                 if (x64_boot_info_phys > max_ktext_map) {
  80                         printf("Cannot access boot info at %#.8x\n", x64_boot_info_phys);
  81                         for(;;);
  82                 }
  83
  84                 boot_info = (BootInfo *)phys_to_ktext(x64_boot_info_phys);
  85                 mem_end = 0;
  86
  87                 if (!(boot_info->flags & (1 << BootInfo::flag_mmap))) {
  88                         // FIXME: use mem_lower and mem_upper in this case.
  89                         printf("MultiBoot info does not contain a memory map.\n");
  90                         for(;;);
  91                 }
  92
  93                 printf("BIOS Memory Map:\n");
  94
  95                 uint off = 0;
  96                 while (off < boot_info->mmap_length) {
  97                         u32 phys = boot_info->mmap_addr + off;
  98
  99                         if (phys > max_ktext_map) {
 100                                 printf("Cannot access BIOS memory map entry at %#.8x\n", phys);
 101                                 for(;;);
 102                         }
 103
 104                         MemMap *mmap = (MemMap *)phys_to_ktext(phys);
 105
 106                         printf("0x%016llx - 0x%016llx, type %d\n",
 107                                mmap->base, mmap->base + mmap->len - 1, mmap->type);
 108
 109                         off += mmap->size + 4;
 110
 111                         if (mmap->type == MemMap::Available) {
 112                                 size_t page_end = (mmap->base + mmap->len) / page_size;
 113
 114                                 if (page_end > mem_end)
 115                                         mem_end = page_end;
 116                         }
 117                 }
 118
 119                 map_physmem();
 120
 121                 off = 0;
 122                 while (off < boot_info->mmap_length) {
 123                         u32 phys = boot_info->mmap_addr + off;
 124                         MemMap *mmap = (MemMap *)phys_to_ktext(phys);
 125                         off += mmap->size + 4;
 126
 127                         if (mmap->type == MemMap::Available) {
 128                                 // Don't use any page that isn't fully in this entry.
 129
 130                                 size_t page_start = (mmap->base + page_size - 1) / page_size;
 131                                 size_t page_end = (mmap->base + mmap->len) / page_size;
 132
 133
 134                                 // Don't make available any pages that overlap the
 135                                 // kernel text/data or bootmem allocations.
 136
 137                                 uintptr_t kernelendpage =
 138                                         (kvirt_to_phys((void *)next_free_bootmem) + page_size - 1) /
 139                                         page_size;
 140
 141                                 // Don't overwrite page 1; the BIOS will need it for later calls in
 142                                 // emulation, and at least the BIOS I'm testing on doesn't mark
 143                                 // it as reserved.
 144
 145                                 if (page_start == 0)
 146                                         page_start = 1;
 147                                 if (page_start >= page_end)
 148                                         continue;
 149
 150                                 if (page_start <= kernelendpage && page_end >= 512) {
 151                                         if (page_start < 512)
 152                                                 make_mem_avail(page_start, 512);
 153
 154                                         if (page_end > kernelendpage)
 155                                                 make_mem_avail(kernelendpage + 1, page_end);
 156                                 } else {
 157                                         make_mem_avail(page_start, page_end);
 158                                 }
 159                         }
 160                 }
 161         }
 162 }
 163 }
 164 }