arch/x86/lib/e820.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
   4  */
   5
   6 #include <efi_loader.h>
   7 #include <asm/e820.h>
   8 #include <asm/global_data.h>
   9
  10 DECLARE_GLOBAL_DATA_PTR;
  11
  12 /*
  13  * Install a default e820 table with 4 entries as follows:
  14  *
  15  *      0x000000-0x0a0000       Useable RAM
  16  *      0x0a0000-0x100000       Reserved for ISA
  17  *      0x100000-gd->ram_size   Useable RAM
  18  *      CONFIG_PCIE_ECAM_BASE   PCIe ECAM
  19  */
  20 __weak unsigned int install_e820_map(unsigned int max_entries,
  21                                      struct e820_entry *entries)
  22 {
  23         entries[0].addr = 0;
  24         entries[0].size = ISA_START_ADDRESS;
  25         entries[0].type = E820_RAM;
  26         entries[1].addr = ISA_START_ADDRESS;
  27         entries[1].size = ISA_END_ADDRESS - ISA_START_ADDRESS;
  28         entries[1].type = E820_RESERVED;
  29         entries[2].addr = ISA_END_ADDRESS;
  30         entries[2].size = gd->ram_size - ISA_END_ADDRESS;
  31         entries[2].type = E820_RAM;
  32         entries[3].addr = CONFIG_PCIE_ECAM_BASE;
  33         entries[3].size = CONFIG_PCIE_ECAM_SIZE;
  34         entries[3].type = E820_RESERVED;
  35
  36         return 4;
  37 }
  38
  39 #if CONFIG_IS_ENABLED(EFI_LOADER)
  40 void efi_add_known_memory(void)
  41 {
  42         struct e820_entry e820[E820MAX];
  43         unsigned int i, num;
  44         u64 start, ram_top;
  45         int type;
  46
  47         num = install_e820_map(ARRAY_SIZE(e820), e820);
  48
  49         ram_top = (u64)gd->ram_top & ~EFI_PAGE_MASK;
  50         if (!ram_top)
  51                 ram_top = 0x100000000ULL;
  52
  53         for (i = 0; i < num; ++i) {
  54                 start = e820[i].addr;
  55
  56                 switch (e820[i].type) {
  57                 case E820_RAM:
  58                         type = EFI_CONVENTIONAL_MEMORY;
  59                         break;
  60                 case E820_RESERVED:
  61                         type = EFI_RESERVED_MEMORY_TYPE;
  62                         break;
  63                 case E820_ACPI:
  64                         type = EFI_ACPI_RECLAIM_MEMORY;
  65                         break;
  66                 case E820_NVS:
  67                         type = EFI_ACPI_MEMORY_NVS;
  68                         break;
  69                 case E820_UNUSABLE:
  70                 default:
  71                         type = EFI_UNUSABLE_MEMORY;
  72                         break;
  73                 }
  74
  75                 if (type == EFI_CONVENTIONAL_MEMORY) {
  76                         efi_add_conventional_memory_map(start,
  77                                                         start + e820[i].size,
  78                                                         ram_top);
  79                 } else {
  80                         efi_add_memory_map(start, e820[i].size, type);
  81                 }
  82         }
  83 }
  84 #endif /* CONFIG_IS_ENABLED(EFI_LOADER) */