xref: /linux/arch/x86/include/uapi/asm/e820.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 #ifndef _UAPI_ASM_X86_E820_H
2 #define _UAPI_ASM_X86_E820_H
3 #define E820MAP	0x2d0		/* our map */
4 #define E820MAX	128		/* number of entries in E820MAP */
5 
6 /*
7  * Legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
8  * constrained space in the zeropage.  If we have more nodes than
9  * that, and if we've booted off EFI firmware, then the EFI tables
10  * passed us from the EFI firmware can list more nodes.  Size our
11  * internal memory map tables to have room for these additional
12  * nodes, based on up to three entries per node for which the
13  * kernel was built: MAX_NUMNODES == (1 << CONFIG_NODES_SHIFT),
14  * plus E820MAX, allowing space for the possible duplicate E820
15  * entries that might need room in the same arrays, prior to the
16  * call to sanitize_e820_map() to remove duplicates.  The allowance
17  * of three memory map entries per node is "enough" entries for
18  * the initial hardware platform motivating this mechanism to make
19  * use of additional EFI map entries.  Future platforms may want
20  * to allow more than three entries per node or otherwise refine
21  * this size.
22  */
23 
24 #ifndef __KERNEL__
25 #define E820_X_MAX E820MAX
26 #endif
27 
28 #define E820NR	0x1e8		/* # entries in E820MAP */
29 
30 #define E820_RAM	1
31 #define E820_RESERVED	2
32 #define E820_ACPI	3
33 #define E820_NVS	4
34 #define E820_UNUSABLE	5
35 #define E820_PMEM	7
36 
37 /*
38  * This is a non-standardized way to represent ADR or NVDIMM regions that
39  * persist over a reboot.  The kernel will ignore their special capabilities
40  * unless the CONFIG_X86_PMEM_LEGACY option is set.
41  *
42  * ( Note that older platforms also used 6 for the same type of memory,
43  *   but newer versions switched to 12 as 6 was assigned differently.  Some
44  *   time they will learn... )
45  */
46 #define E820_PRAM	12
47 
48 /*
49  * reserved RAM used by kernel itself
50  * if CONFIG_INTEL_TXT is enabled, memory of this type will be
51  * included in the S3 integrity calculation and so should not include
52  * any memory that BIOS might alter over the S3 transition
53  */
54 #define E820_RESERVED_KERN        128
55 
56 #ifndef __ASSEMBLY__
57 #include <linux/types.h>
58 struct e820entry {
59 	__u64 addr;	/* start of memory segment */
60 	__u64 size;	/* size of memory segment */
61 	__u32 type;	/* type of memory segment */
62 } __attribute__((packed));
63 
64 struct e820map {
65 	__u32 nr_map;
66 	struct e820entry map[E820_X_MAX];
67 };
68 
69 #define ISA_START_ADDRESS	0xa0000
70 #define ISA_END_ADDRESS		0x100000
71 
72 #define BIOS_BEGIN		0x000a0000
73 #define BIOS_END		0x00100000
74 
75 #define BIOS_ROM_BASE		0xffe00000
76 #define BIOS_ROM_END		0xffffffff
77 
78 #endif /* __ASSEMBLY__ */
79 
80 
81 #endif /* _UAPI_ASM_X86_E820_H */
82