1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2#ifndef _ASM_X86_E820_H
3#define _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#define E820_X_MAX E820MAX
26
27#define E820NR 0x1e8 /* # entries in E820MAP */
28
29#define E820_RAM 1
30#define E820_RESERVED 2
31#define E820_ACPI 3
32#define E820_NVS 4
33#define E820_UNUSABLE 5
34#define E820_PMEM 7
35
36/*
37 * This is a non-standardized way to represent ADR or NVDIMM regions that
38 * persist over a reboot. The kernel will ignore their special capabilities
39 * unless the CONFIG_X86_PMEM_LEGACY option is set.
40 *
41 * ( Note that older platforms also used 6 for the same type of memory,
42 * but newer versions switched to 12 as 6 was assigned differently. Some
43 * time they will learn... )
44 */
45#define E820_PRAM 12
46
47/*
48 * reserved RAM used by kernel itself
49 * if CONFIG_INTEL_TXT is enabled, memory of this type will be
50 * included in the S3 integrity calculation and so should not include
51 * any memory that BIOS might alter over the S3 transition
52 */
53#define E820_RESERVED_KERN 128
54
55#ifndef __ASSEMBLER__
56#include <linux/types.h>
57struct e820entry {
58 __u64 addr; /* start of memory segment */
59 __u64 size; /* size of memory segment */
60 __u32 type; /* type of memory segment */
61} __attribute__((packed));
62
63struct e820map {
64 __u32 nr_map;
65 struct e820entry map[E820_X_MAX];
66};
67
68#define ISA_START_ADDRESS 0xa0000
69#define ISA_END_ADDRESS 0x100000
70
71#define BIOS_BEGIN 0x000a0000
72#define BIOS_END 0x00100000
73
74#define BIOS_ROM_BASE 0xffe00000
75#define BIOS_ROM_END 0xffffffff
76
77#endif /* __ASSEMBLER__ */
78
79
80#endif /* _ASM_X86_E820_H */