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      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 */
     83