[PATCH v3 26/30] efi_loader: Avoid mapping the ACPI tables twice

Simon Glass sjg at chromium.org
Sat Jan 11 01:00:25 CET 2025


The add_u_boot_and_runtime() function paints with a broad brush,
considering all of the memory from the top of U-Boot stack to
gd->ram_top as EFI_RUNTIME_SERVICES_CODE

This is fine, but we need to make sure we don't add a separate entry for
any ACPI tables in this region (which happens when bloblist is used for
tables). Otherwise the memory map looks strange and we get a test
failure on qemu-x86 (only) for the 'virtual address map' test.

Good map:

   Type             Start            End              Attributes
   ================ ================ ================ ==========
   CONVENTIONAL     0000000000000000-00000000000a0000 WB
   RESERVED         00000000000a0000-00000000000f0000 WB
   RUNTIME DATA     00000000000f0000-00000000000f2000 WB|RT
   RESERVED         00000000000f2000-0000000000100000 WB
   CONVENTIONAL     0000000000100000-0000000005cc7000 WB
   BOOT DATA        0000000005cc7000-0000000005ccc000 WB
   RUNTIME DATA     0000000005ccc000-0000000005ccd000 WB|RT
   BOOT DATA        0000000005ccd000-0000000005cce000 WB
   RUNTIME DATA     0000000005cce000-0000000005cf0000 WB|RT
   BOOT DATA        0000000005cf0000-0000000006cf5000 WB
   RESERVED         0000000006cf5000-0000000006cfa000 WB
   ACPI RECLAIM MEM 0000000006cfa000-0000000006d1c000 WB
   RESERVED         0000000006d1c000-0000000006f35000 WB
   RUNTIME CODE     0000000006f35000-0000000006f37000 WB|RT
   RESERVED         0000000006f37000-0000000008000000 WB
   RESERVED         00000000e0000000-00000000f0000000 WB

Bad map: (with BLOBLIST_TABLES but without this patch):

   Type             Start            End              Attributes
   ================ ================ ================ ==========
   CONVENTIONAL     0000000000000000-00000000000a0000 WB
   RESERVED         00000000000a0000-00000000000f0000 WB
   ACPI RECLAIM MEM 00000000000f0000-00000000000f1000 WB
   RESERVED         00000000000f1000-0000000000100000 WB
   CONVENTIONAL     0000000000100000-0000000005ca5000 WB
   BOOT DATA        0000000005ca5000-0000000005caa000 WB
   RUNTIME DATA     0000000005caa000-0000000005cab000 WB|RT
   BOOT DATA        0000000005cab000-0000000005cac000 WB
   RUNTIME DATA     0000000005cac000-0000000005cce000 WB|RT
   BOOT DATA        0000000005cce000-0000000006cd3000 WB
   RUNTIME DATA     0000000006cd3000-0000000006cd5000 WB|RT
   BOOT DATA        0000000006cd5000-0000000006cf4000 WB
   RESERVED         0000000006cf4000-0000000006cf9000 WB
   ACPI RECLAIM MEM 0000000006cf9000-0000000006ce6000 WB

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
- Add new patch to avoid mapping the ACPI tables twice

 lib/efi_loader/efi_acpi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/efi_loader/efi_acpi.c b/lib/efi_loader/efi_acpi.c
index 67bd7f8ca24..ff305a6b13e 100644
--- a/lib/efi_loader/efi_acpi.c
+++ b/lib/efi_loader/efi_acpi.c
@@ -25,6 +25,16 @@ efi_status_t efi_acpi_register(void)
 	ulong addr, start, end;
 	efi_status_t ret;
 
+	/*
+	 * The bloblist is already marked reserved. For now, we don't bother
+	 * marking it with EFI_ACPI_RECLAIM_MEMORY since we would need to cut a
+	 * hole in the EFI_BOOT_SERVICES_CODE region added by
+	 * add_u_boot_and_runtime(). At some point that function could create a
+	 * more detailed map.
+	 */
+	if (IS_ENABLED(CONFIG_BLOBLIST_TABLES))
+		return EFI_SUCCESS;
+
 	/* Mark space used for tables */
 	start = ALIGN_DOWN(gd->arch.table_start, EFI_PAGE_MASK);
 	end = ALIGN(gd->arch.table_end, EFI_PAGE_MASK);
-- 
2.34.1



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