hw/i386/e820_memory_layout.c

   1 /*
   2  * QEMU BIOS e820 routines
   3  *
   4  * Copyright (c) 2003-2004 Fabrice Bellard
   5  *
   6  * SPDX-License-Identifier: MIT
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "qemu/bswap.h"
  11 #include "e820_memory_layout.h"
  12
  13 static size_t e820_entries;
  14 struct e820_table e820_reserve;
  15 struct e820_entry *e820_table;
  16
  17 int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
  18 {
  19     int index = le32_to_cpu(e820_reserve.count);
  20     struct e820_entry *entry;
  21
  22     if (type != E820_RAM) {
  23         /* old FW_CFG_E820_TABLE entry -- reservations only */
  24         if (index >= E820_NR_ENTRIES) {
  25             return -EBUSY;
  26         }
  27         entry = &e820_reserve.entry[index++];
  28
  29         entry->address = cpu_to_le64(address);
  30         entry->length = cpu_to_le64(length);
  31         entry->type = cpu_to_le32(type);
  32
  33         e820_reserve.count = cpu_to_le32(index);
  34     }
  35
  36     /* new "etc/e820" file -- include ram too */
  37     e820_table = g_renew(struct e820_entry, e820_table, e820_entries + 1);
  38     e820_table[e820_entries].address = cpu_to_le64(address);
  39     e820_table[e820_entries].length = cpu_to_le64(length);
  40     e820_table[e820_entries].type = cpu_to_le32(type);
  41     e820_entries++;
  42
  43     return e820_entries;
  44 }
  45
  46 int e820_get_num_entries(void)
  47 {
  48     return e820_entries;
  49 }
  50
  51 bool e820_get_entry(int idx, uint32_t type, uint64_t *address, uint64_t *length)
  52 {
  53     if (idx < e820_entries && e820_table[idx].type == cpu_to_le32(type)) {
  54         *address = le64_to_cpu(e820_table[idx].address);
  55         *length = le64_to_cpu(e820_table[idx].length);
  56         return true;
  57     }
  58     return false;
  59 }