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-rw-r--r--src/include/ipxe/efi/efi_table.h37
-rw-r--r--src/include/ipxe/errfile.h1
-rw-r--r--src/interface/efi/efi_init.c19
-rw-r--r--src/interface/efi/efi_table.c178
4 files changed, 217 insertions, 18 deletions
diff --git a/src/include/ipxe/efi/efi_table.h b/src/include/ipxe/efi/efi_table.h
new file mode 100644
index 000000000..9a41d8723
--- /dev/null
+++ b/src/include/ipxe/efi/efi_table.h
@@ -0,0 +1,37 @@
+#ifndef _IPXE_EFI_TABLE_H
+#define _IPXE_EFI_TABLE_H
+
+/** @file
+ *
+ * EFI configuration tables
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <ipxe/efi/efi.h>
+
+/** An installable EFI configuration table type */
+struct efi_table {
+ /** Table GUID */
+ EFI_GUID *guid;
+ /**
+ * Determine length of table
+ *
+ * @v data Configuration table data (presumed valid)
+ * @ret len Length of table
+ *
+ * EFI does not record the length of installed configuration
+ * tables. Consumers must understand the specific type of
+ * table in order to be able to determine its length from the
+ * contents.
+ */
+ size_t ( * len ) ( const void *data );
+};
+
+extern void * efi_find_table ( EFI_GUID *guid );
+extern int efi_install_table ( struct efi_table *table, const void *data,
+ void **backup );
+extern int efi_uninstall_table ( struct efi_table *table, void **backup );
+
+#endif /* _IPXE_EFI_TABLE_H */
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 51b458d56..a64104a22 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -85,6 +85,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#define ERRFILE_efi_service ( ERRFILE_CORE | 0x002d0000 )
#define ERRFILE_null_smbios ( ERRFILE_CORE | 0x002e0000 )
#define ERRFILE_efi_open ( ERRFILE_CORE | 0x002f0000 )
+#define ERRFILE_efi_table ( ERRFILE_CORE | 0x00300000 )
#define ERRFILE_eisa ( ERRFILE_DRIVER | 0x00000000 )
#define ERRFILE_isa ( ERRFILE_DRIVER | 0x00010000 )
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index 1ba144ee7..69aea0d50 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -25,6 +25,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#include <ipxe/init.h>
#include <ipxe/rotate.h>
#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_table.h>
#include <ipxe/efi/efi_driver.h>
#include <ipxe/efi/efi_path.h>
#include <ipxe/efi/efi_cmdline.h>
@@ -104,24 +105,6 @@ static EFIAPI void efi_shutdown_hook ( EFI_EVENT event __unused,
}
/**
- * Look up EFI configuration table
- *
- * @v guid Configuration table GUID
- * @ret table Configuration table, or NULL
- */
-static void * efi_find_table ( EFI_GUID *guid ) {
- unsigned int i;
-
- for ( i = 0 ; i < efi_systab->NumberOfTableEntries ; i++ ) {
- if ( memcmp ( &efi_systab->ConfigurationTable[i].VendorGuid,
- guid, sizeof ( *guid ) ) == 0 )
- return efi_systab->ConfigurationTable[i].VendorTable;
- }
-
- return NULL;
-}
-
-/**
* Construct a stack cookie value
*
* @v handle Image handle
diff --git a/src/interface/efi/efi_table.c b/src/interface/efi/efi_table.c
new file mode 100644
index 000000000..3c3f35a4b
--- /dev/null
+++ b/src/interface/efi/efi_table.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_table.h>
+
+/** @file
+ *
+ * EFI configuration tables
+ *
+ */
+
+/**
+ * Look up EFI configuration table
+ *
+ * @v guid Configuration table GUID
+ * @ret table Configuration table, or NULL
+ */
+void * efi_find_table ( EFI_GUID *guid ) {
+ void *table;
+ unsigned int i;
+
+ /* Scan for installed table */
+ for ( i = 0 ; i < efi_systab->NumberOfTableEntries ; i++ ) {
+ if ( memcmp ( &efi_systab->ConfigurationTable[i].VendorGuid,
+ guid, sizeof ( *guid ) ) == 0 ) {
+ table = efi_systab->ConfigurationTable[i].VendorTable;
+ DBGC ( guid, "EFITAB %s is at %p\n",
+ efi_guid_ntoa ( guid ), table );
+ return table;
+ }
+ }
+
+ return NULL;
+}
+
+/**
+ * Install EFI configuration table
+ *
+ * @v table Configuration table type
+ * @v data Configuration table data, or NULL to uninstall
+ * @v backup Table backup, or NULL to not back up old table
+ * @ret rc Return status code
+ */
+int efi_install_table ( struct efi_table *table, const void *data,
+ void **backup ) {
+ EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+ EFI_GUID *guid = table->guid;
+ void *copy;
+ void *new;
+ void *old;
+ size_t old_len;
+ size_t new_len;
+ EFI_STATUS efirc;
+ int rc;
+
+ /* Get currently installed table, if any */
+ old = efi_find_table ( guid );
+ old_len = ( old ? table->len ( old ) : 0 );
+
+ /* Create backup copy, if applicable */
+ if ( old_len && backup ) {
+ if ( ( efirc = bs->AllocatePool ( EfiBootServicesData, old_len,
+ &copy ) ) != 0 ) {
+ rc = -EEFI ( efirc );
+ goto err_backup;
+ }
+ memcpy ( copy, old, old_len );
+ DBGC ( table, "EFITAB %s %p+%#zx backed up\n",
+ efi_guid_ntoa ( guid ), old, old_len );
+ } else {
+ copy = NULL;
+ }
+
+ /* Create installable runtime services data copy, if applicable */
+ new_len = ( data ? table->len ( data ) : 0 );
+ if ( new_len ) {
+ if ( ( efirc = bs->AllocatePool ( EfiRuntimeServicesData,
+ new_len, &new ) ) != 0 ) {
+ rc = -EEFI ( efirc );
+ goto err_allocate;
+ }
+ memcpy ( new, data, new_len );
+ } else {
+ new = NULL;
+ }
+
+ /* (Un)install configuration table, if applicable */
+ if ( new || old ) {
+ if ( ( efirc = bs->InstallConfigurationTable ( guid,
+ new ) ) != 0 ) {
+ rc = -EEFI ( efirc );
+ DBGC ( table, "EFITAB %s could not install: %s\n",
+ efi_guid_ntoa ( guid ), strerror ( rc ) );
+ goto err_install;
+ }
+ if ( old ) {
+ DBGC ( table, "EFITAB %s %p+%#zx uninstalled\n",
+ efi_guid_ntoa ( guid ), old, old_len );
+ }
+ if ( new ) {
+ DBGC ( table, "EFITAB %s %p+%#zx installed\n",
+ efi_guid_ntoa ( guid ), new, new_len );
+ }
+ }
+
+ /* Record backup copy, if applicable */
+ if ( backup ) {
+ if ( *backup )
+ bs->FreePool ( *backup );
+ *backup = copy;
+ }
+
+ /* Sanity check */
+ assert ( efi_find_table ( guid ) == new );
+
+ return 0;
+
+ err_install:
+ if ( new )
+ bs->FreePool ( new );
+ err_allocate:
+ if ( copy )
+ bs->FreePool ( copy );
+ err_backup:
+ return rc;
+}
+
+/**
+ * Uninstall EFI configuration table
+ *
+ * @v table Configuration table type
+ * @v backup Table backup (or NULL to not restore old table)
+ * @ret rc Return status code
+ */
+int efi_uninstall_table ( struct efi_table *table, void **backup ) {
+ EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+ void *old;
+ int rc;
+
+ /* Uninstall or reinstall as applicable */
+ old = ( backup ? *backup : NULL );
+ if ( ( rc = efi_install_table ( table, old, NULL ) ) != 0 )
+ return rc;
+
+ /* Free backup copy, if applicable */
+ if ( backup && *backup ) {
+ bs->FreePool ( *backup );
+ *backup = NULL;
+ }
+
+ return 0;
+}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2026-07-30 10:47:25 +0200