As the name suggest. Lists the currently installed UEFI configuration tables. I used this to check the contents of the Memory Attributes Table.
fs0:> list-cfg-tbl.efi
GUID:ee4e5898-3914-4259-9d6e-dc7bd79403cf, Address:0x6a5e1f18
GUID:05ad34ba-6f02-4214-952e-4da0398e2bb9, Address:0x589d6da0
GUID:7739f24c-93d7-11d4-9a3a-0090273fc14d, Address:0x6a5b6018
GUID:4c19049f-4137-4dd3-9c10-8b97a83ffdfa, Address:0x589d6710
GUID:49152e77-1ada-4764-b7a2-7afefed95e8b, Address:0x589d8510
GUID:00781ca1-5de3-405f-abb8-379c3c076984, Address:0x6fde0d18
GUID:64d120b4-4448-5fff-8376-f4b17994ec35, Address:0x6b5f2110
GUID:8868e871-e4f1-11d3-bc22-0080c73c8881, Address:0x6ce8c000
GUID:eb9d2d30-2d88-11d3-9a16-0090273fc14d, Address:0x6ce8c000
GUID:eb9d2d31-2d88-11d3-9a16-0090273fc14d, Address:0xf0000
GUID:f2fd1544-9794-4a2c-992e-e5bbcf20e394, Address:0xf0020
GUID:1e2ed096-30e2-4254-bd89-863bbef82325, Address:0x6d7c3000
GUID:b122a263-3661-4f68-9929-78f8b0d62180, Address:0x6fa4b798
GUID:dcfa911d-26eb-469f-a220-38b7dc461220, Address:0x68cde018
Here is annotated contents of the table on my system.
fs0:> dmem 68cde018 1000
Memory Address 0000000068CDE018 1000 Bytes
; https://uefi.org/specs/UEFI/2.10/04_EFI_System_Table.html#efi-memory-attributes-table
68CDE018: 01 00 00 00 ; Version
27 00 00 00- ; NumberOfEntries
30 00 00 00 ; DescriptorSize
00 00 00 00 *....'...0.......* ; Flags
; https://github.com/tianocore/edk2/blob/e32b58ab5a12d37c82327f28376e7d12cccc8b3a/MdePkg/Include/Uefi/UefiSpec.h#L175
; https://github.com/tianocore/edk2/blob/e32b58ab5a12d37c82327f28376e7d12cccc8b3a/MdePkg/Include/Uefi/UefiMultiPhase.h#L112
68CDE028: 06 00 00 00 ; Type = EfiRuntimeServicesData
00 00 00 00-
00 90 BD 5B 00 00 00 00 *...........[....*
68CDE038: 00 00 00 00 00 00 00 00-
01 00 00 00 00 00 00 00 *................*
68CDE048: 00 40 00 00 00 00 00 80- ; Attribute = EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
00 00 00 00 00 00 00 00 *.@..............*
68CDE058: 06 00 00 00 00 00 00 00-00 50 86 6D 00 00 00 00 *.........P.m....*
68CDE068: 00 00 00 00 00 00 00 00-7E 25 00 00 00 00 00 00 *........~%......*
68CDE078: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE088: 05 00 00 00 00 00 00 00-00 30 DE 6F 00 00 00 00 *.........0.o....*
68CDE098: 00 00 00 00 00 00 00 00-6D 00 00 00 00 00 00 00 *........m.......*
68CDE0A8: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE0B8: 05 00 00 00 00 00 00 00-00 00 E5 6F 00 00 00 00 *...........o....*
68CDE0C8: 00 00 00 00 00 00 00 00-02 00 00 00 00 00 00 00 *................*
68CDE0D8: 00 00 02 00 00 00 00 80-00 00 00 00 00 00 00 00 *................* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE0E8: 05 00 00 00 00 00 00 00-00 20 E5 6F 00 00 00 00 *......... .o....*
68CDE0F8: 00 00 00 00 00 00 00 00-04 00 00 00 00 00 00 00 *................*
68CDE108: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE118: 05 00 00 00 00 00 00 00-00 60 E5 6F 00 00 00 00 *.........`.o....*
68CDE128: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE138: 00 00 02 00 00 00 00 80-00 00 00 00 00 00 00 00 *................* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE148: 05 00 00 00 00 00 00 00-00 70 E5 6F 00 00 00 00 *.........p.o....*
68CDE158: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE168: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE178: 05 00 00 00 00 00 00 00-00 C0 E5 6F 00 00 00 00 *...........o....*
68CDE188: 00 00 00 00 00 00 00 00-04 00 00 00 00 00 00 00 *................*
68CDE198: 00 00 02 00 00 00 00 80-00 00 00 00 00 00 00 00 *................* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE1A8: 05 00 00 00 00 00 00 00-00 00 E6 6F 00 00 00 00 *...........o....*
68CDE1B8: 00 00 00 00 00 00 00 00-06 00 00 00 00 00 00 00 *................*
68CDE1C8: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE1D8: 05 00 00 00 00 00 00 00-00 60 E6 6F 00 00 00 00 *.........`.o....*
68CDE1E8: 00 00 00 00 00 00 00 00-03 00 00 00 00 00 00 00 *................*
68CDE1F8: 00 00 02 00 00 00 00 80-00 00 00 00 00 00 00 00 *................* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE208: 05 00 00 00 00 61 00 66-00 90 E6 6F 00 00 00 00 *.....a.f...o....*
68CDE218: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE228: 00 40 00 00 00 00 00 80-00 00 00 00 00 00 00 00 *.@..............* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE238: 05 00 00 00 00 75 00 6E-00 E0 E6 6F 00 00 00 00 *.....u.n...o....*
68CDE248: 00 00 00 00 00 00 00 00-02 00 00 00 00 00 00 00 *................*
68CDE258: 00 00 02 00 00 00 00 80-00 00 00 00 00 00 00 00 *................* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE268: 05 00 00 00 00 6D 00 70-00 00 E7 6F 00 00 00 00 *.....m.p...o....*
68CDE278: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE288: 00 40 00 00 00 00 00 80-43 00 6F 00 6D 00 70 00 *.@......C.o.m.p.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE298: 05 00 00 00 00 73 00 6F-00 50 E7 6F 00 00 00 00 *.....s.o.P.o....*
68CDE2A8: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE2B8: 00 00 02 00 00 00 00 80-00 76 00 69 00 63 00 65 *.........v.i.c.e* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE2C8: 05 00 00 00 00 6F 00 6D-00 60 E7 6F 00 00 00 00 *.....o.m.`.o....*
68CDE2D8: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE2E8: 00 40 00 00 00 00 00 80-00 6F 00 72 00 74 00 20 *.@.......o.r.t. * ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE2F8: 05 00 00 00 00 20 00 49-00 B0 E7 6F 00 00 00 00 *..... .I...o....*
68CDE308: 00 00 00 00 00 00 00 00-C5 00 00 00 00 00 00 00 *................*
68CDE318: 00 00 02 00 00 00 00 80-00 72 00 6F 00 67 00 72 *.........r.o.g.r* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE328: 05 00 00 00 00 64 00 2C-00 00 F4 6F 00 00 00 00 *.....d.,...o....*
68CDE338: 00 00 00 00 00 00 00 00-4F 00 00 00 00 00 00 00 *........O.......*
68CDE348: 00 40 00 00 00 00 00 80-00 79 00 73 00 74 00 65 *.@.......y.s.t.e* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE358: 05 00 00 00 00 6F 00 72-00 F0 F8 6F 00 00 00 00 *.....o.r...o....*
68CDE368: 00 00 00 00 00 00 00 00-0E 00 00 00 00 00 00 00 *................*
68CDE378: 00 00 02 00 00 00 00 80-00 20 00 74 00 68 00 65 *......... .t.h.e* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE388: 05 00 00 00 00 6F 00 6E-00 D0 F9 6F 00 00 00 00 *.....o.n...o....*
68CDE398: 00 00 00 00 00 00 00 00-0A 00 00 00 00 00 00 00 *................*
68CDE3A8: 00 40 00 00 00 00 00 80-00 76 00 61 00 6C 00 75 *.@.......v.a.l.u* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE3B8: 05 00 00 00 00 65 00 6F-00 70 FA 6F 00 00 00 00 *.....e.o.p.o....*
68CDE3C8: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE3D8: 00 00 02 00 00 00 00 80-00 20 00 35 00 30 00 6D *......... .5.0.m* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE3E8: 05 00 00 00 00 49 00 20-00 80 FA 6F 00 00 00 00 *.....I. ...o....*
68CDE3F8: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE408: 00 40 00 00 00 00 00 80-00 65 00 6C 00 65 00 63 *.@.......e.l.e.c* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE418: 05 00 00 00 6F 00 20 00-00 D0 FA 6F 00 00 00 00 *....o. ....o....*
68CDE428: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE438: 00 00 02 00 00 00 00 80-00 73 00 65 00 20 00 73 *.........s.e. .s* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE448: 05 00 00 00 65 00 61 00-00 E0 FA 6F 00 00 00 00 *....e.a....o....*
68CDE458: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE468: 00 40 00 00 00 00 00 80-00 73 00 20 00 73 00 75 *.@.......s. .s.u* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE478: 05 00 00 00 66 00 69 00-00 30 FB 6F 00 00 00 00 *....f.i..0.o....*
68CDE488: 00 00 00 00 00 00 00 00-03 00 00 00 00 00 00 00 *................*
68CDE498: 00 00 02 00 00 00 00 80-00 20 00 49 00 66 00 20 *......... .I.f. * ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE4A8: 05 00 00 00 74 00 20 00-00 60 FB 6F 00 00 00 00 *....t. ..`.o....*
68CDE4B8: 00 00 00 00 00 00 00 00-06 00 00 00 00 00 00 00 *................*
68CDE4C8: 00 40 00 00 00 00 00 80-00 2C 00 20 00 73 00 6F *.@.......,. .s.o* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE4D8: 05 00 00 00 6F 00 20 00-00 C0 FB 6F 00 00 00 00 *....o. ....o....*
68CDE4E8: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE4F8: 00 00 02 00 00 00 00 80-00 65 00 72 00 20 00 74 *.........e.r. .t* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE508: 05 00 00 00 52 00 65 00-00 D0 FB 6F 00 00 00 00 *....R.e....o....*
68CDE518: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE528: 00 40 00 00 00 00 00 80-75 00 6C 00 74 00 00 00 *.@......u.l.t...* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE538: 05 00 00 00 20 00 69 00-00 20 FC 6F 00 00 00 00 *.... .i.. .o....*
68CDE548: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE558: 00 00 02 00 00 00 00 80-75 00 70 00 70 00 6F 00 *........u.p.p.o.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE568: 05 00 00 00 61 00 74 00-00 30 FC 6F 00 00 00 00 *....a.t..0.o....*
68CDE578: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE588: 00 40 00 00 00 00 00 80-20 00 73 00 65 00 74 00 *.@...... .s.e.t.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE598: 05 00 00 00 00 6F 00 6D-00 80 FC 6F 00 00 00 00 *.....o.m...o....*
68CDE5A8: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE5B8: 00 00 02 00 00 00 00 80-6F 00 77 00 6E 00 73 00 *........o.w.n.s.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE5C8: 05 00 00 00 00 14 49 00-00 90 FC 6F 00 00 00 00 *......I....o....*
68CDE5D8: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE5E8: 00 40 00 00 00 00 00 80-69 00 74 00 73 00 20 00 *.@......i.t.s. .* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE5F8: 05 00 00 00 74 00 68 00-00 E0 FC 6F 00 00 00 00 *....t.h....o....*
68CDE608: 00 00 00 00 00 00 00 00-01 00 00 00 00 00 00 00 *................*
68CDE618: 00 00 02 00 00 00 00 80-75 00 6D 00 62 00 65 00 *........u.m.b.e.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE628: 05 00 00 00 41 00 74 00-00 F0 FC 6F 00 00 00 00 *....A.t....o....*
68CDE638: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE648: 00 40 00 00 00 00 00 80-72 00 63 00 65 00 6D 00 *.@......r.c.e.m.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE658: 05 00 00 00 69 00 73 00-00 40 FD 6F 00 00 00 00 *....i.s..@.o....*
68CDE668: 00 00 00 00 00 00 00 00-0C 00 00 00 00 00 00 00 *................*
68CDE678: 00 00 02 00 00 00 00 80-79 00 70 00 65 00 31 00 *........y.p.e.1.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE688: 05 00 00 00 65 00 72 00-00 00 FE 6F 00 00 00 00 *....e.r....o....*
68CDE698: 00 00 00 00 00 00 00 00-08 00 00 00 00 00 00 00 *................*
68CDE6A8: 00 40 00 00 00 00 00 80-73 00 74 00 20 00 69 00 *.@......s.t. .i.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE6B8: 05 00 00 00 79 00 20 00-00 80 FE 6F 00 00 00 00 *....y. ....o....*
68CDE6C8: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE6D8: 00 00 02 00 00 00 00 80-61 00 74 00 69 00 6F 00 *........a.t.i.o.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE6E8: 05 00 00 00 6E 00 61 00-00 D0 FE 6F 00 00 00 00 *....n.a....o....*
68CDE6F8: 00 00 00 00 00 00 00 00-06 00 00 00 00 00 00 00 *................*
68CDE708: 00 40 00 00 00 00 00 80-67 00 20 00 61 00 63 00 *.@......g. .a.c.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME
68CDE718: 05 00 00 00 6F 00 72 00-00 30 FF 6F 00 00 00 00 *....o.r..0.o....*
68CDE728: 00 00 00 00 00 00 00 00-05 00 00 00 00 00 00 00 *................*
68CDE738: 00 00 02 00 00 00 00 80-63 00 74 00 69 00 6F 00 *........c.t.i.o.* ; EFI_MEMORY_RO | EFI_MEMORY_RUNTIME
68CDE748: 05 00 00 00 00 4F 00 20-00 80 FF 6F 00 00 00 00 *.....O. ...o....*
68CDE758: 00 00 00 00 00 00 00 00-07 00 00 00 00 00 00 00 *................*
68CDE768: 00 40 00 00 00 00 00 80-69 00 6D 00 6D 00 65 00 *.@......i.m.m.e.* ; EFI_MEMORY_XP | EFI_MEMORY_RUNTIME