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>
59 struct 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
65 struct 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 */