From: Simon Glass <sjg@chromium.org> Provide a command to sync reserved-memory with EFI's version of reserved memory. Co-developed-by: Claude <noreply@anthropic.com> Signed-off-by: Simon Glass <sjg@chromium.org> --- cmd/efi.c | 22 ++++++++++++++++++++-- doc/usage/cmd/efi.rst | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+), 2 deletions(-) diff --git a/cmd/efi.c b/cmd/efi.c index c59219ddf01..c329e6eede8 100644 --- a/cmd/efi.c +++ b/cmd/efi.c @@ -198,9 +198,26 @@ static int do_efi_tables(struct cmd_tbl *cmdtp, int flag, int argc, return 0; } +static int do_efi_memsync(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + bool verbose = false; + int ret; + + if (argc > 1 && !strcmp(argv[1], "-v")) + verbose = true; + + ret = efi_mem_reserved_sync(working_fdt, verbose); + if (ret < 0) + return CMD_RET_FAILURE; + + return 0; +} + static struct cmd_tbl efi_commands[] = { U_BOOT_CMD_MKENT(image, 1, 1, do_efi_image, "", ""), U_BOOT_CMD_MKENT(mem, 1, 1, do_efi_mem, "", ""), + U_BOOT_CMD_MKENT(memsync, 2, 1, do_efi_memsync, "", ""), U_BOOT_CMD_MKENT(tables, 1, 1, do_efi_tables, "", ""), }; @@ -223,9 +240,10 @@ static int do_efi(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) } U_BOOT_CMD( - efi, 3, 1, do_efi, + efi, 4, 1, do_efi, "EFI access", "image Dump loaded-image info\n" "mem [all] Dump memory information [include boot services]\n" - "tables Dump tables" + "memsync [-v] Sync EFI memory map with DT reserved-memory\n" + "tables Dump tables" ); diff --git a/doc/usage/cmd/efi.rst b/doc/usage/cmd/efi.rst index e5d8913c94b..f91a2bd7bec 100644 --- a/doc/usage/cmd/efi.rst +++ b/doc/usage/cmd/efi.rst @@ -14,6 +14,7 @@ Synopsis efi image efi mem [all] + efi memsync [-v] efi tables Description @@ -69,6 +70,24 @@ Attributes Shows a code for memory attributes. The key for this is shown below the table. +efi memsync +~~~~~~~~~~~ + +This synchronizes EFI reserved memory regions with the device tree's +reserved-memory nodes. When running as an EFI application, U-Boot can access +the EFI memory map to identify regions that EFI considers reserved (such as +runtime services code/data, ACPI tables, etc.). This command compares these +EFI reserved regions with the device tree's /reserved-memory nodes and adds +any missing regions to prevent Linux from using memory that EFI has reserved. + +Use the optional '-v' flag for verbose output showing the detailed memory +map analysis. Without this flag, only errors are displayed. + +This is useful for ensuring proper memory management when transitioning from +EFI boot services to the operating system, particularly in complex firmware +environments where EFI may have reserved memory regions not explicitly +documented in the device tree. + efi tables ~~~~~~~~~~ @@ -234,3 +253,20 @@ Example 000000001fb7e000 eb9d2d30-2d88-11d3-9a16-0090273fc14d EFI_GUID_EFI_ACPI1 000000001fb7e014 8868e871-e4f1-11d3-bc22-0080c73c8881 ACPI table 000000001e654018 dcfa911d-26eb-469f-a220-38b7dc461220 (unknown) + + => efi memsync + Regions added: 2 + + => efi memsync -v + Comparing EFI memory-map with reserved-memory + EFI Memory Map Analysis: + ID Type Start End In DT? + ------------------------------------------------------------------------ + 0 EFI_RUNTIME_SERVICES_CODE 0x001f9ef000 0x001faef000 no -> adding + 1 EFI_ACPI_RECLAIM_MEMORY 0x001fb6f000 0x001fb7f000 no -> adding + 2 EFI_ACPI_MEMORY_NVS 0x001fb7f000 0x001fbff000 yes + Regions added: 2 + Reserved memory regions: + 0 tcg_event_log 0x100000 0x2000 + 1 efi-runtime-services-code@1f9ef000 0x1f9ef000 0x100000 + 2 efi-acpi-reclaim@1fb6f000 0x1fb6f000 0x10000 -- 2.43.0