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torvalds
GitHub Repository: torvalds/linux
Path: blob/master/arch/x86/include/uapi/asm/e820.h
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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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#ifndef _UAPI_ASM_X86_E820_H
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#define _UAPI_ASM_X86_E820_H
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#define E820MAP 0x2d0 /* our map */
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#define E820MAX 128 /* number of entries in E820MAP */
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/*
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* Legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
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* constrained space in the zeropage. If we have more nodes than
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* that, and if we've booted off EFI firmware, then the EFI tables
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* passed us from the EFI firmware can list more nodes. Size our
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* internal memory map tables to have room for these additional
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* nodes, based on up to three entries per node for which the
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* kernel was built: MAX_NUMNODES == (1 << CONFIG_NODES_SHIFT),
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* plus E820MAX, allowing space for the possible duplicate E820
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* entries that might need room in the same arrays, prior to the
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* call to sanitize_e820_map() to remove duplicates. The allowance
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* of three memory map entries per node is "enough" entries for
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* the initial hardware platform motivating this mechanism to make
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* use of additional EFI map entries. Future platforms may want
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* to allow more than three entries per node or otherwise refine
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* this size.
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*/
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#ifndef __KERNEL__
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#define E820_X_MAX E820MAX
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#endif
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#define E820NR 0x1e8 /* # entries in E820MAP */
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#define E820_RAM 1
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#define E820_RESERVED 2
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#define E820_ACPI 3
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#define E820_NVS 4
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#define E820_UNUSABLE 5
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#define E820_PMEM 7
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/*
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* This is a non-standardized way to represent ADR or NVDIMM regions that
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* persist over a reboot. The kernel will ignore their special capabilities
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* unless the CONFIG_X86_PMEM_LEGACY option is set.
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*
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* ( Note that older platforms also used 6 for the same type of memory,
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* but newer versions switched to 12 as 6 was assigned differently. Some
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* time they will learn... )
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*/
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#define E820_PRAM 12
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/*
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* reserved RAM used by kernel itself
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* if CONFIG_INTEL_TXT is enabled, memory of this type will be
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* included in the S3 integrity calculation and so should not include
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* any memory that BIOS might alter over the S3 transition
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*/
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#define E820_RESERVED_KERN 128
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#ifndef __ASSEMBLER__
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#include <linux/types.h>
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struct e820entry {
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__u64 addr; /* start of memory segment */
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__u64 size; /* size of memory segment */
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__u32 type; /* type of memory segment */
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} __attribute__((packed));
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struct e820map {
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__u32 nr_map;
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struct e820entry map[E820_X_MAX];
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};
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#define ISA_START_ADDRESS 0xa0000
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#define ISA_END_ADDRESS 0x100000
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#define BIOS_BEGIN 0x000a0000
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#define BIOS_END 0x00100000
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#define BIOS_ROM_BASE 0xffe00000
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#define BIOS_ROM_END 0xffffffff
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#endif /* __ASSEMBLER__ */
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#endif /* _UAPI_ASM_X86_E820_H */
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