xref: /openbmc/linux/arch/x86/include/uapi/asm/e820.h (revision 0da85d1e)
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  * 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=y 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 __ASSEMBLY__
56 #include <linux/types.h>
57 struct 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 
63 struct 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 /* __ASSEMBLY__ */
78 
79 
80 #endif /* _UAPI_ASM_X86_E820_H */
81