xref: /linux/arch/x86/include/uapi/asm/e820.h (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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 
36 
37 /*
38  * reserved RAM used by kernel itself
39  * if CONFIG_INTEL_TXT is enabled, memory of this type will be
40  * included in the S3 integrity calculation and so should not include
41  * any memory that BIOS might alter over the S3 transition
42  */
43 #define E820_RESERVED_KERN        128
44 
45 #ifndef __ASSEMBLY__
46 #include <linux/types.h>
47 struct e820entry {
48 	__u64 addr;	/* start of memory segment */
49 	__u64 size;	/* size of memory segment */
50 	__u32 type;	/* type of memory segment */
51 } __attribute__((packed));
52 
53 struct e820map {
54 	__u32 nr_map;
55 	struct e820entry map[E820_X_MAX];
56 };
57 
58 #define ISA_START_ADDRESS	0xa0000
59 #define ISA_END_ADDRESS		0x100000
60 
61 #define BIOS_BEGIN		0x000a0000
62 #define BIOS_END		0x00100000
63 
64 #define BIOS_ROM_BASE		0xffe00000
65 #define BIOS_ROM_END		0xffffffff
66 
67 #endif /* __ASSEMBLY__ */
68 
69 
70 #endif /* _UAPI_ASM_X86_E820_H */
71