LXR linux/arch/x86/include/uapi/asm/e820.h

   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2#ifndef _UAPI_ASM_X86_E820_H
   3#define _UAPI_ASM_X86_E820_H
   4#define E820MAP 0x2d0           /* our map */
   5#define E820MAX 128             /* number of entries in E820MAP */
   6
   7/*
   8 * Legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
   9 * constrained space in the zeropage.  If we have more nodes than
  10 * that, and if we've booted off EFI firmware, then the EFI tables
  11 * passed us from the EFI firmware can list more nodes.  Size our
  12 * internal memory map tables to have room for these additional
  13 * nodes, based on up to three entries per node for which the
  14 * kernel was built: MAX_NUMNODES == (1 << CONFIG_NODES_SHIFT),
  15 * plus E820MAX, allowing space for the possible duplicate E820
  16 * entries that might need room in the same arrays, prior to the
  17 * call to sanitize_e820_map() to remove duplicates.  The allowance
  18 * of three memory map entries per node is "enough" entries for
  19 * the initial hardware platform motivating this mechanism to make
  20 * use of additional EFI map entries.  Future platforms may want
  21 * to allow more than three entries per node or otherwise refine
  22 * this size.
  23 */
  24
  25#ifndef __KERNEL__
  26#define E820_X_MAX E820MAX
  27#endif
  28
  29#define E820NR  0x1e8           /* # entries in E820MAP */
  30
  31#define E820_RAM        1
  32#define E820_RESERVED   2
  33#define E820_ACPI       3
  34#define E820_NVS        4
  35#define E820_UNUSABLE   5
  36#define E820_PMEM       7
  37
  38/*
  39 * This is a non-standardized way to represent ADR or NVDIMM regions that
  40 * persist over a reboot.  The kernel will ignore their special capabilities
  41 * unless the CONFIG_X86_PMEM_LEGACY option is set.
  42 *
  43 * ( Note that older platforms also used 6 for the same type of memory,
  44 *   but newer versions switched to 12 as 6 was assigned differently.  Some
  45 *   time they will learn... )
  46 */
  47#define E820_PRAM       12
  48
  49/*
  50 * reserved RAM used by kernel itself
  51 * if CONFIG_INTEL_TXT is enabled, memory of this type will be
  52 * included in the S3 integrity calculation and so should not include
  53 * any memory that BIOS might alter over the S3 transition
  54 */
  55#define E820_RESERVED_KERN        128
  56
  57#ifndef __ASSEMBLY__
  58#include <linux/types.h>
  59struct e820entry {
  60        __u64 addr;     /* start of memory segment */
  61        __u64 size;     /* size of memory segment */
  62        __u32 type;     /* type of memory segment */
  63} __attribute__((packed));
  64
  65struct e820map {
  66        __u32 nr_map;
  67        struct e820entry map[E820_X_MAX];
  68};
  69
  70#define ISA_START_ADDRESS       0xa0000
  71#define ISA_END_ADDRESS         0x100000
  72
  73#define BIOS_BEGIN              0x000a0000
  74#define BIOS_END                0x00100000
  75
  76#define BIOS_ROM_BASE           0xffe00000
  77#define BIOS_ROM_END            0xffffffff
  78
  79#endif /* __ASSEMBLY__ */
  80
  81
  82#endif /* _UAPI_ASM_X86_E820_H */
  83