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