--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+
+.. Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
+
+efi command
+===========
+
+Synopsis
+--------
+
+::
+
+ efi mem [all]
+
+Description
+-----------
+
+The *efi* command provides information about the EFI environment U-Boot is
+running in, when it is started from EFI.
+
+When running as an EFI app, this command queries EFI boot services for the
+information. When running as an EFI payload, EFI boot services have been
+stopped, so it uses the information collected by the boot stub before that
+happened.
+
+efi mem
+~~~~~~~
+
+This shows the EFI memory map, sorted in order of physical address.
+
+This is normally a very large table. To help reduce the amount of detritus,
+boot-time memory is normally merged with conventional memory. Use the 'all'
+argument to show everything.
+
+The fields are as follows:
+
+#
+ Entry number (sequentially from 0)
+
+Type
+ Memory type. EFI has a large number of memory types. The type is shown in
+ the format <n>:<name> where in is the format number in hex and <name> is the
+ name.
+
+Physical
+ Physical address
+
+Virtual
+ Virtual address
+
+Size
+ Size of memory area in bytes
+
+Attributes
+ Shows a code for memory attributes. The key for this is shown below the
+ table.
+
+Example
+-------
+
+::
+
+ => efi mem
+ EFI table at 0, memory map 000000001ad38b60, size 1260, key a79, version 1, descr. size 0x30
+ # Type Physical Virtual Size Attributes
+ 0 7:conv 0000000000 0000000000 00000a0000 f
+ <gap> 00000a0000 0000060000
+ 1 7:conv 0000100000 0000000000 0000700000 f
+ 2 a:acpi_nvs 0000800000 0000000000 0000008000 f
+ 3 7:conv 0000808000 0000000000 0000008000 f
+ 4 a:acpi_nvs 0000810000 0000000000 00000f0000 f
+ 5 7:conv 0000900000 0000000000 001efef000 f
+ 6 6:rt_data 001f8ef000 0000000000 0000100000 rf
+ 7 5:rt_code 001f9ef000 0000000000 0000100000 rf
+ 8 0:reserved 001faef000 0000000000 0000080000 f
+ 9 9:acpi_reclaim 001fb6f000 0000000000 0000010000 f
+ 10 a:acpi_nvs 001fb7f000 0000000000 0000080000 f
+ 11 7:conv 001fbff000 0000000000 0000359000 f
+ 12 6:rt_data 001ff58000 0000000000 0000020000 rf
+ 13 a:acpi_nvs 001ff78000 0000000000 0000088000 f
+ <gap> 0020000000 0090000000
+ 14 0:reserved 00b0000000 0000000000 0010000000 1
+
+ Attributes key:
+ f: uncached, write-coalescing, write-through, write-back
+ rf: uncached, write-coalescing, write-through, write-back, needs runtime mapping
+ 1: uncached
+ *Some areas are merged (use 'all' to see)
+
+
+ => efi mem all
+ EFI table at 0, memory map 000000001ad38bb0, size 1260, key a79, version 1, descr. size 0x30
+ # Type Physical Virtual Size Attributes
+ 0 3:bs_code 0000000000 0000000000 0000001000 f
+ 1 7:conv 0000001000 0000000000 000009f000 f
+ <gap> 00000a0000 0000060000
+ 2 7:conv 0000100000 0000000000 0000700000 f
+ 3 a:acpi_nvs 0000800000 0000000000 0000008000 f
+ 4 7:conv 0000808000 0000000000 0000008000 f
+ 5 a:acpi_nvs 0000810000 0000000000 00000f0000 f
+ 6 4:bs_data 0000900000 0000000000 0000c00000 f
+ 7 7:conv 0001500000 0000000000 000aa36000 f
+ 8 2:loader_data 000bf36000 0000000000 0010000000 f
+ 9 4:bs_data 001bf36000 0000000000 0000020000 f
+ 10 7:conv 001bf56000 0000000000 00021e1000 f
+ 11 1:loader_code 001e137000 0000000000 00000c4000 f
+ 12 7:conv 001e1fb000 0000000000 000009b000 f
+ 13 1:loader_code 001e296000 0000000000 00000e2000 f
+ 14 7:conv 001e378000 0000000000 000005b000 f
+ 15 4:bs_data 001e3d3000 0000000000 000001e000 f
+ 16 7:conv 001e3f1000 0000000000 0000016000 f
+ 17 4:bs_data 001e407000 0000000000 0000016000 f
+ 18 2:loader_data 001e41d000 0000000000 0000002000 f
+ 19 4:bs_data 001e41f000 0000000000 0000828000 f
+ 20 3:bs_code 001ec47000 0000000000 0000045000 f
+ 21 4:bs_data 001ec8c000 0000000000 0000001000 f
+ 22 3:bs_code 001ec8d000 0000000000 000000e000 f
+ 23 4:bs_data 001ec9b000 0000000000 0000001000 f
+ 24 3:bs_code 001ec9c000 0000000000 000002c000 f
+ 25 4:bs_data 001ecc8000 0000000000 0000001000 f
+ 26 3:bs_code 001ecc9000 0000000000 000000c000 f
+ 27 4:bs_data 001ecd5000 0000000000 0000006000 f
+ 28 3:bs_code 001ecdb000 0000000000 0000014000 f
+ 29 4:bs_data 001ecef000 0000000000 0000001000 f
+ 30 3:bs_code 001ecf0000 0000000000 000005b000 f
+ 31 4:bs_data 001ed4b000 0000000000 000000b000 f
+ 32 3:bs_code 001ed56000 0000000000 0000024000 f
+ 33 4:bs_data 001ed7a000 0000000000 0000006000 f
+ 34 3:bs_code 001ed80000 0000000000 0000010000 f
+ 35 4:bs_data 001ed90000 0000000000 0000002000 f
+ 36 3:bs_code 001ed92000 0000000000 0000025000 f
+ 37 4:bs_data 001edb7000 0000000000 0000003000 f
+ 38 3:bs_code 001edba000 0000000000 0000011000 f
+ 39 4:bs_data 001edcb000 0000000000 0000008000 f
+ 40 3:bs_code 001edd3000 0000000000 000002d000 f
+ 41 4:bs_data 001ee00000 0000000000 0000201000 f
+ 42 3:bs_code 001f001000 0000000000 0000024000 f
+ 43 4:bs_data 001f025000 0000000000 0000002000 f
+ 44 3:bs_code 001f027000 0000000000 0000009000 f
+ 45 4:bs_data 001f030000 0000000000 0000005000 f
+ 46 3:bs_code 001f035000 0000000000 000002f000 f
+ 47 4:bs_data 001f064000 0000000000 0000001000 f
+ 48 3:bs_code 001f065000 0000000000 0000005000 f
+ 49 4:bs_data 001f06a000 0000000000 0000005000 f
+ 50 3:bs_code 001f06f000 0000000000 0000007000 f
+ 51 4:bs_data 001f076000 0000000000 0000007000 f
+ 52 3:bs_code 001f07d000 0000000000 000000d000 f
+ 53 4:bs_data 001f08a000 0000000000 0000001000 f
+ 54 3:bs_code 001f08b000 0000000000 0000006000 f
+ 55 4:bs_data 001f091000 0000000000 0000004000 f
+ 56 3:bs_code 001f095000 0000000000 000000d000 f
+ 57 4:bs_data 001f0a2000 0000000000 0000003000 f
+ 58 3:bs_code 001f0a5000 0000000000 0000026000 f
+ 59 4:bs_data 001f0cb000 0000000000 0000005000 f
+ 60 3:bs_code 001f0d0000 0000000000 0000019000 f
+ 61 4:bs_data 001f0e9000 0000000000 0000004000 f
+ 62 3:bs_code 001f0ed000 0000000000 0000024000 f
+ 63 4:bs_data 001f111000 0000000000 0000008000 f
+ 64 3:bs_code 001f119000 0000000000 000000b000 f
+ 65 4:bs_data 001f124000 0000000000 0000001000 f
+ 66 3:bs_code 001f125000 0000000000 0000002000 f
+ 67 4:bs_data 001f127000 0000000000 0000002000 f
+ 68 3:bs_code 001f129000 0000000000 0000009000 f
+ 69 4:bs_data 001f132000 0000000000 0000003000 f
+ 70 3:bs_code 001f135000 0000000000 0000005000 f
+ 71 4:bs_data 001f13a000 0000000000 0000003000 f
+ 72 3:bs_code 001f13d000 0000000000 0000005000 f
+ 73 4:bs_data 001f142000 0000000000 0000003000 f
+ 74 3:bs_code 001f145000 0000000000 0000011000 f
+ 75 4:bs_data 001f156000 0000000000 000000b000 f
+ 76 3:bs_code 001f161000 0000000000 0000009000 f
+ 77 4:bs_data 001f16a000 0000000000 0000400000 f
+ 78 3:bs_code 001f56a000 0000000000 0000006000 f
+ 79 4:bs_data 001f570000 0000000000 0000001000 f
+ 80 3:bs_code 001f571000 0000000000 0000001000 f
+ 81 4:bs_data 001f572000 0000000000 0000002000 f
+ 82 3:bs_code 001f574000 0000000000 0000017000 f
+ 83 4:bs_data 001f58b000 0000000000 0000364000 f
+ 84 6:rt_data 001f8ef000 0000000000 0000100000 rf
+ 85 5:rt_code 001f9ef000 0000000000 0000100000 rf
+ 86 0:reserved 001faef000 0000000000 0000080000 f
+ 87 9:acpi_reclaim 001fb6f000 0000000000 0000010000 f
+ 88 a:acpi_nvs 001fb7f000 0000000000 0000080000 f
+ 89 4:bs_data 001fbff000 0000000000 0000201000 f
+ 90 7:conv 001fe00000 0000000000 00000e8000 f
+ 91 4:bs_data 001fee8000 0000000000 0000020000 f
+ 92 3:bs_code 001ff08000 0000000000 0000026000 f
+ 93 4:bs_data 001ff2e000 0000000000 0000009000 f
+ 94 3:bs_code 001ff37000 0000000000 0000021000 f
+ 95 6:rt_data 001ff58000 0000000000 0000020000 rf
+ 96 a:acpi_nvs 001ff78000 0000000000 0000088000 f
+ <gap> 0020000000 0090000000
+ 97 0:reserved 00b0000000 0000000000 0010000000 1
+
+ Attributes key:
+ f: uncached, write-coalescing, write-through, write-back
+ rf: uncached, write-coalescing, write-through, write-back, needs runtime mapping
+ 1: uncached