uapi/asm/e820.h

0001 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
0002 #ifndef _UAPI_ASM_X86_E820_H
0003 #define _UAPI_ASM_X86_E820_H
0004 #define E820MAP 0x2d0       /* our map */
0005 #define E820MAX 128     /* number of entries in E820MAP */
0006
0007 /*
0008  * Legacy E820 BIOS limits us to 128 (E820MAX) nodes due to the
0009  * constrained space in the zeropage.  If we have more nodes than
0010  * that, and if we've booted off EFI firmware, then the EFI tables
0011  * passed us from the EFI firmware can list more nodes.  Size our
0012  * internal memory map tables to have room for these additional
0013  * nodes, based on up to three entries per node for which the
0014  * kernel was built: MAX_NUMNODES == (1 << CONFIG_NODES_SHIFT),
0015  * plus E820MAX, allowing space for the possible duplicate E820
0016  * entries that might need room in the same arrays, prior to the
0017  * call to sanitize_e820_map() to remove duplicates.  The allowance
0018  * of three memory map entries per node is "enough" entries for
0019  * the initial hardware platform motivating this mechanism to make
0020  * use of additional EFI map entries.  Future platforms may want
0021  * to allow more than three entries per node or otherwise refine
0022  * this size.
0023  */
0024
0025 #ifndef __KERNEL__
0026 #define E820_X_MAX E820MAX
0027 #endif
0028
0029 #define E820NR  0x1e8       /* # entries in E820MAP */
0030
0031 #define E820_RAM    1
0032 #define E820_RESERVED   2
0033 #define E820_ACPI   3
0034 #define E820_NVS    4
0035 #define E820_UNUSABLE   5
0036 #define E820_PMEM   7
0037
0038 /*
0039  * This is a non-standardized way to represent ADR or NVDIMM regions that
0040  * persist over a reboot.  The kernel will ignore their special capabilities
0041  * unless the CONFIG_X86_PMEM_LEGACY option is set.
0042  *
0043  * ( Note that older platforms also used 6 for the same type of memory,
0044  *   but newer versions switched to 12 as 6 was assigned differently.  Some
0045  *   time they will learn... )
0046  */
0047 #define E820_PRAM   12
0048
0049 /*
0050  * reserved RAM used by kernel itself
0051  * if CONFIG_INTEL_TXT is enabled, memory of this type will be
0052  * included in the S3 integrity calculation and so should not include
0053  * any memory that BIOS might alter over the S3 transition
0054  */
0055 #define E820_RESERVED_KERN        128
0056
0057 #ifndef __ASSEMBLY__
0058 #include <linux/types.h>
0059 struct e820entry {
0060     __u64 addr; /* start of memory segment */
0061     __u64 size; /* size of memory segment */
0062     __u32 type; /* type of memory segment */
0063 } __attribute__((packed));
0064
0065 struct e820map {
0066     __u32 nr_map;
0067     struct e820entry map[E820_X_MAX];
0068 };
0069
0070 #define ISA_START_ADDRESS   0xa0000
0071 #define ISA_END_ADDRESS     0x100000
0072
0073 #define BIOS_BEGIN      0x000a0000
0074 #define BIOS_END        0x00100000
0075
0076 #define BIOS_ROM_BASE       0xffe00000
0077 #define BIOS_ROM_END        0xffffffff
0078
0079 #endif /* __ASSEMBLY__ */
0080
0081
0082 #endif /* _UAPI_ASM_X86_E820_H */