WIP - EFI settings

src/arch/x86/image/bzimage.c

@@ -355,6 +355,10 @@ static size_t bzimage_load_initrd ( struct image *image,
 	size_t offset;
 	size_t pad_len;
 
+	/* Do not include kernel image itself as an initrd */
+	if ( initrd == image )
+		return 0;
+
 	/* Create cpio header for non-prebuilt images */
 	offset = cpio_header ( initrd, &cpio );
 
@@ -402,6 +406,10 @@ static int bzimage_check_initrds ( struct image *image,
 	/* Calculate total loaded length of initrds */
 	for_each_image ( initrd ) {
 
+		/* Skip kernel */
+		if ( initrd == image )
+			continue;
+
 		/* Calculate length */
 		len += bzimage_load_initrd ( image, initrd, UNULL );
 		len = bzimage_align ( len );

src/arch/x86/image/multiboot.c

@@ -204,6 +204,10 @@ static int multiboot_add_modules ( struct image *image, physaddr_t start,
 			break;
 		}
 
+		/* Do not include kernel image itself as a module */
+		if ( module_image == image )
+			continue;
+
 		/* Page-align the module */
 		start = ( ( start + 0xfff ) & ~0xfff );
 

src/config/config.c

@@ -352,6 +352,9 @@ REQUIRE_OBJECT ( vram_settings );
 #ifdef ACPI_SETTINGS
 REQUIRE_OBJECT ( acpi_settings );
 #endif
+#ifdef EFI_SETTINGS
+REQUIRE_OBJECT ( efi_settings );
+#endif
 
 /*
  * Drag in selected keyboard map

src/config/defaults/efi.h

@@ -48,6 +48,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #define	REBOOT_CMD		/* Reboot command */
 
+#define EFI_SETTINGS		/* EFI variable settings */
+
 #if defined ( __i386__ ) || defined ( __x86_64__ )
 #define IOAPI_X86
 #define NAP_EFIX86

src/config/settings.h

@@ -9,6 +9,8 @@
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
+#include <config/defaults.h>
+
 #define	PCI_SETTINGS	/* PCI device settings */
 //#define	CPUID_SETTINGS	/* CPUID settings */
 //#define	MEMMAP_SETTINGS	/* Memory map settings */

src/core/image.c

@@ -312,7 +312,7 @@ void unregister_image ( struct image *image ) {
 struct image * find_image ( const char *name ) {
 	struct image *image;
 
-	for_each_image ( image ) {
+	list_for_each_entry ( image, &images, list ) {
 		if ( strcmp ( image->name, name ) == 0 )
 			return image;
 	}
@@ -349,8 +349,9 @@ int image_exec ( struct image *image ) {
 	/* Preserve record of any currently-running image */
 	saved_current_image = current_image;
 
-	/* Take out a temporary reference to the image, so that it
-	 * does not get freed when temporarily unregistered.
+	/* Take out a temporary reference to the image.  This allows
+	 * the image to unregister itself if necessary, without
+	 * automatically freeing itself.
 	 */
 	current_image = image_get ( image );
 
@@ -370,9 +371,6 @@ int image_exec ( struct image *image ) {
 	/* Record boot attempt */
 	syslog ( LOG_NOTICE, "Executing \"%s\"\n", image->name );
 
-	/* Temporarily unregister the image during its execution */
-	unregister_image ( image );
-
 	/* Try executing the image */
 	if ( ( rc = image->type->exec ( image ) ) != 0 ) {
 		DBGC ( image, "IMAGE %s could not execute: %s\n",
@@ -389,10 +387,6 @@ int image_exec ( struct image *image ) {
 			 image->name, strerror ( rc ) );
 	}
 
-	/* Re-register image (unless due to be replaced) */
-	if ( ! image->replacement )
-		register_image ( image );
-
 	/* Pick up replacement image before we drop the original
 	 * image's temporary reference.  The replacement image must
 	 * already be registered, so we don't need to hold a temporary

src/drivers/net/intelx.c

@@ -473,7 +473,6 @@ static struct pci_device_id intelx_nics[] = {
 	PCI_ROM ( 0x8086, 0x10f9, "82599-cx4", "82599 (CX4)", 0 ),
 	PCI_ROM ( 0x8086, 0x10fb, "82599-sfp", "82599 (SFI/SFP+)", 0 ),
 	PCI_ROM ( 0x8086, 0x10fc, "82599-xaui", "82599 (XAUI/BX4)", 0 ),
-	PCI_ROM ( 0x8086, 0x151c, "82599-tn", "82599 (TN)", 0 ),
 	PCI_ROM ( 0x8086, 0x1528, "x540t", "X540-AT2/X540-BT2", 0 ),
 	PCI_ROM ( 0x8086, 0x154d, "82599-sfp-sf2", "82599 (SFI/SFP+)", 0 ),
 	PCI_ROM ( 0x8086, 0x1557, "82599en-sfp", "82599 (Single Port SFI Only)", 0 ),

src/drivers/net/netvsc.c

@@ -852,9 +852,16 @@ static int netvsc_reset ( struct vmbus_device *vmdev ) {
 	struct net_device *netdev = rndis->netdev;
 	int rc;
 
-	/* Reset network device */
-	if ( ( rc = netdev_reset ( netdev ) ) != 0 ) {
-		DBGC ( netvsc, "NETVSC %s could not reset: %s\n",
+	/* A closed device holds no NetVSC (or RNDIS) state, so there
+	 * is nothing to reset.
+	 */
+	if ( ! netdev_is_open ( netdev ) )
+		return 0;
+
+	/* Close and reopen device to reset any stale state */
+	netdev_close ( netdev );
+	if ( ( rc = netdev_open ( netdev ) ) != 0 ) {
+		DBGC ( netvsc, "NETVSC %s could not reopen: %s\n",
 		       netvsc->name, strerror ( rc ) );
 		return rc;
 	}

src/image/efi_image.c

@@ -147,38 +147,38 @@ static int efi_image_exec ( struct image *image ) {
 	/* Find an appropriate device handle to use */
 	snpdev = last_opened_snpdev();
 	if ( ! snpdev ) {
-		DBGC ( image, "EFIIMAGE %s could not identify SNP device\n",
-		       image->name );
+		DBGC ( image, "EFIIMAGE %p could not identify SNP device\n",
+		       image );
 		rc = -ENODEV;
 		goto err_no_snpdev;
 	}
 
 	/* Install file I/O protocols */
 	if ( ( rc = efi_file_install ( snpdev->handle ) ) != 0 ) {
-		DBGC ( image, "EFIIMAGE %s could not install file protocol: "
-		       "%s\n", image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not install file protocol: "
+		       "%s\n", image, strerror ( rc ) );
 		goto err_file_install;
 	}
 
 	/* Install PXE base code protocol */
 	if ( ( rc = efi_pxe_install ( snpdev->handle, snpdev->netdev ) ) != 0 ){
-		DBGC ( image, "EFIIMAGE %s could not install PXE protocol: "
-		       "%s\n", image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not install PXE protocol: "
+		       "%s\n", image, strerror ( rc ) );
 		goto err_pxe_install;
 	}
 
 	/* Install iPXE download protocol */
 	if ( ( rc = efi_download_install ( snpdev->handle ) ) != 0 ) {
-		DBGC ( image, "EFIIMAGE %s could not install iPXE download "
-		       "protocol: %s\n", image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not install iPXE download "
+		       "protocol: %s\n", image, strerror ( rc ) );
 		goto err_download_install;
 	}
 
 	/* Create device path for image */
 	path = efi_image_path ( image, snpdev->path );
 	if ( ! path ) {
-		DBGC ( image, "EFIIMAGE %s could not create device path\n",
-		       image->name );
+		DBGC ( image, "EFIIMAGE %p could not create device path\n",
+		       image );
 		rc = -ENOMEM;
 		goto err_image_path;
 	}
@@ -186,8 +186,8 @@ static int efi_image_exec ( struct image *image ) {
 	/* Create command line for image */
 	cmdline = efi_image_cmdline ( image );
 	if ( ! cmdline ) {
-		DBGC ( image, "EFIIMAGE %s could not create command line\n",
-		       image->name );
+		DBGC ( image, "EFIIMAGE %p could not create command line\n",
+		       image );
 		rc = -ENOMEM;
 		goto err_cmdline;
 	}
@@ -199,8 +199,8 @@ static int efi_image_exec ( struct image *image ) {
 				       image->len, &handle ) ) != 0 ) {
 		/* Not an EFI image */
 		rc = -EEFI_LOAD ( efirc );
-		DBGC ( image, "EFIIMAGE %s could not load: %s\n",
-		       image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not load: %s\n",
+		       image, strerror ( rc ) );
 		if ( efirc == EFI_SECURITY_VIOLATION ) {
 			goto err_load_image_security_violation;
 		} else {
@@ -220,8 +220,8 @@ static int efi_image_exec ( struct image *image ) {
 
 	/* Some EFI 1.10 implementations seem not to fill in DeviceHandle */
 	if ( loaded.image->DeviceHandle == NULL ) {
-		DBGC ( image, "EFIIMAGE %s filling in missing DeviceHandle\n",
-		       image->name );
+		DBGC ( image, "EFIIMAGE %p filling in missing DeviceHandle\n",
+		       image );
 		loaded.image->DeviceHandle = snpdev->handle;
 	}
 
@@ -251,14 +251,14 @@ static int efi_image_exec ( struct image *image ) {
 	/* Start the image */
 	if ( ( efirc = bs->StartImage ( handle, NULL, NULL ) ) != 0 ) {
 		rc = -EEFI_START ( efirc );
-		DBGC ( image, "EFIIMAGE %s could not start (or returned with "
-		       "error): %s\n", image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not start (or returned with "
+		       "error): %s\n", image, strerror ( rc ) );
 		goto err_start_image;
 	}
 
 	/* If image was a driver, connect it up to anything available */
 	if ( type == EfiBootServicesCode ) {
-		DBGC ( image, "EFIIMAGE %s connecting drivers\n", image->name );
+		DBGC ( image, "EFIIMAGE %p connecting drivers\n", image );
 		efi_driver_reconnect_all();
 	}
 
@@ -324,8 +324,8 @@ static int efi_image_probe ( struct image *image ) {
 				       image->len, &handle ) ) != 0 ) {
 		/* Not an EFI image */
 		rc = -EEFI_LOAD ( efirc );
-		DBGC ( image, "EFIIMAGE %s could not load: %s\n",
-		       image->name, strerror ( rc ) );
+		DBGC ( image, "EFIIMAGE %p could not load: %s\n",
+		       image, strerror ( rc ) );
 		if ( efirc == EFI_SECURITY_VIOLATION ) {
 			goto err_load_image_security_violation;
 		} else {

src/image/script.c

@@ -197,6 +197,11 @@ static int script_exec ( struct image *image ) {
 	size_t saved_offset;
 	int rc;
 
+	/* Temporarily de-register image, so that a "boot" command
+	 * doesn't throw us into an execution loop.
+	 */
+	unregister_image ( image );
+
 	/* Preserve state of any currently-running script */
 	saved_offset = script_offset;
 
@@ -207,6 +212,10 @@ static int script_exec ( struct image *image ) {
 	/* Restore saved state */
 	script_offset = saved_offset;
 
+	/* Re-register image (unless we have been replaced) */
+	if ( ! image->replacement )
+		register_image ( image );
+
 	return rc;
 }
 

src/include/ipxe/efi/Guid/GlobalVariable.h

@@ -0,0 +1,188 @@
+/** @file
+  GUID for EFI (NVRAM) Variables.
+
+  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+  @par Revision Reference:
+  GUID defined in UEFI 2.1
+**/
+
+#ifndef __GLOBAL_VARIABLE_GUID_H__
+#define __GLOBAL_VARIABLE_GUID_H__
+
+FILE_LICENCE ( BSD2_PATENT );
+
+#define EFI_GLOBAL_VARIABLE \
+  { \
+    0x8BE4DF61, 0x93CA, 0x11d2, {0xAA, 0x0D, 0x00, 0xE0, 0x98, 0x03, 0x2B, 0x8C } \
+  }
+
+extern EFI_GUID  gEfiGlobalVariableGuid;
+
+//
+// Follow UEFI 2.4 spec:
+// To prevent name collisions with possible future globally defined variables,
+// other internal firmware data variables that are not defined here must be
+// saved with a unique VendorGuid other than EFI_GLOBAL_VARIABLE or
+// any other GUID defined by the UEFI Specification. Implementations must
+// only permit the creation of variables with a UEFI Specification-defined
+// VendorGuid when these variables are documented in the UEFI Specification.
+//
+// Note: except the globally defined variables defined below, the spec also defines
+// L"Boot####"      - A boot load option.
+// L"Driver####"    - A driver load option.
+// L"SysPrep####"   - A System Prep application load option.
+// L"Key####"       - Describes hot key relationship with a Boot#### load option.
+// The attribute for them is NV+BS+RT, #### is a printed hex value, and no 0x or h
+// is included in the hex value. They can not be expressed as a #define like other globally
+// defined variables, it is because we can not list the Boot0000, Boot0001, etc one by one.
+//
+
+///
+/// The language codes that the firmware supports. This value is deprecated.
+/// Its attribute is BS+RT.
+///
+#define EFI_LANG_CODES_VARIABLE_NAME  L"LangCodes"
+///
+/// The language code that the system is configured for. This value is deprecated.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_LANG_VARIABLE_NAME  L"Lang"
+///
+/// The firmware's boot managers timeout, in seconds, before initiating the default boot selection.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_TIME_OUT_VARIABLE_NAME  L"Timeout"
+///
+/// The language codes that the firmware supports.
+/// Its attribute is BS+RT.
+///
+#define EFI_PLATFORM_LANG_CODES_VARIABLE_NAME  L"PlatformLangCodes"
+///
+/// The language code that the system is configured for.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_PLATFORM_LANG_VARIABLE_NAME  L"PlatformLang"
+///
+/// The device path of the default input/output/error output console.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_CON_IN_VARIABLE_NAME   L"ConIn"
+#define EFI_CON_OUT_VARIABLE_NAME  L"ConOut"
+#define EFI_ERR_OUT_VARIABLE_NAME  L"ErrOut"
+///
+/// The device path of all possible input/output/error output devices.
+/// Its attribute is BS+RT.
+///
+#define EFI_CON_IN_DEV_VARIABLE_NAME   L"ConInDev"
+#define EFI_CON_OUT_DEV_VARIABLE_NAME  L"ConOutDev"
+#define EFI_ERR_OUT_DEV_VARIABLE_NAME  L"ErrOutDev"
+///
+/// The ordered boot option load list.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_BOOT_ORDER_VARIABLE_NAME  L"BootOrder"
+///
+/// The boot option for the next boot only.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_BOOT_NEXT_VARIABLE_NAME  L"BootNext"
+///
+/// The boot option that was selected for the current boot.
+/// Its attribute is BS+RT.
+///
+#define EFI_BOOT_CURRENT_VARIABLE_NAME  L"BootCurrent"
+///
+/// The types of boot options supported by the boot manager. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_BOOT_OPTION_SUPPORT_VARIABLE_NAME  L"BootOptionSupport"
+///
+/// The ordered driver load option list.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_DRIVER_ORDER_VARIABLE_NAME  L"DriverOrder"
+///
+/// The ordered System Prep Application load option list.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_SYS_PREP_ORDER_VARIABLE_NAME  L"SysPrepOrder"
+///
+/// Identifies the level of hardware error record persistence
+/// support implemented by the platform. This variable is
+/// only modified by firmware and is read-only to the OS.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_HW_ERR_REC_SUPPORT_VARIABLE_NAME  L"HwErrRecSupport"
+///
+/// Whether the system is operating in setup mode (1) or not (0).
+/// All other values are reserved. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_SETUP_MODE_NAME  L"SetupMode"
+///
+/// The Key Exchange Key Signature Database.
+/// Its attribute is NV+BS+RT+AT.
+///
+#define EFI_KEY_EXCHANGE_KEY_NAME  L"KEK"
+///
+/// The public Platform Key.
+/// Its attribute is NV+BS+RT+AT.
+///
+#define EFI_PLATFORM_KEY_NAME  L"PK"
+///
+/// Array of GUIDs representing the type of signatures supported
+/// by the platform firmware. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_SIGNATURE_SUPPORT_NAME  L"SignatureSupport"
+///
+/// Whether the platform firmware is operating in Secure boot mode (1) or not (0).
+/// All other values are reserved. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_SECURE_BOOT_MODE_NAME  L"SecureBoot"
+///
+/// The OEM's default Key Exchange Key Signature Database. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_KEK_DEFAULT_VARIABLE_NAME  L"KEKDefault"
+///
+/// The OEM's default public Platform Key. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_PK_DEFAULT_VARIABLE_NAME  L"PKDefault"
+///
+/// The OEM's default secure boot signature store. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_DB_DEFAULT_VARIABLE_NAME  L"dbDefault"
+///
+/// The OEM's default secure boot blacklist signature store. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_DBX_DEFAULT_VARIABLE_NAME  L"dbxDefault"
+///
+/// The OEM's default secure boot timestamp signature store. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_DBT_DEFAULT_VARIABLE_NAME  L"dbtDefault"
+///
+/// Allows the firmware to indicate supported features and actions to the OS.
+/// Its attribute is BS+RT.
+///
+#define EFI_OS_INDICATIONS_SUPPORT_VARIABLE_NAME  L"OsIndicationsSupported"
+///
+/// Allows the OS to request the firmware to enable certain features and to take certain actions.
+/// Its attribute is NV+BS+RT.
+///
+#define EFI_OS_INDICATIONS_VARIABLE_NAME  L"OsIndications"
+///
+/// Whether the system is configured to use only vendor provided
+/// keys or not. Should be treated as read-only.
+/// Its attribute is BS+RT.
+///
+#define EFI_VENDOR_KEYS_VARIABLE_NAME  L"VendorKeys"
+
+#endif

src/include/ipxe/errfile.h

@@ -404,6 +404,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_dhe		      ( ERRFILE_OTHER | 0x005a0000 )
 #define ERRFILE_efi_cmdline	      ( ERRFILE_OTHER | 0x005b0000 )
 #define ERRFILE_efi_rng		      ( ERRFILE_OTHER | 0x005c0000 )
+#define ERRFILE_efi_settings	      ( ERRFILE_OTHER | 0x005d0000 )
 
 /** @} */
 

src/include/ipxe/netdevice.h

@@ -723,7 +723,6 @@ extern struct net_device * alloc_netdev ( size_t priv_size );
 extern int register_netdev ( struct net_device *netdev );
 extern int netdev_open ( struct net_device *netdev );
 extern void netdev_close ( struct net_device *netdev );
-extern int netdev_reset ( struct net_device *netdev );
 extern void unregister_netdev ( struct net_device *netdev );
 extern void netdev_irq ( struct net_device *netdev, int enable );
 extern struct net_device * find_netdev ( const char *name );

src/interface/efi/efi_file.c

@@ -130,7 +130,7 @@ static struct image * efi_file_find ( const char *name ) {
 	struct image *image;
 
 	/* Find image */
-	for_each_image ( image ) {
+	list_for_each_entry ( image, &images, list ) {
 		if ( strcasecmp ( image->name, name ) == 0 )
 			return image;
 	}
@@ -240,6 +240,10 @@ static size_t efi_file_read_initrd ( struct efi_file_reader *reader ) {
 	len = 0;
 	for_each_image ( image ) {
 
+		/* Ignore currently executing image */
+		if ( image == current_image )
+			continue;
+
 		/* Pad to alignment boundary */
 		pad_len = ( ( -reader->pos ) & ( INITRD_ALIGN - 1 ) );
 		if ( pad_len ) {
@@ -1087,7 +1091,7 @@ int efi_file_install ( EFI_HANDLE handle ) {
 	 * instance only if the initrd is non-empty, since Linux does
 	 * not gracefully handle a zero-length initrd.
 	 */
-	load = ( have_images() ? &efi_file_initrd.load : NULL );
+	load = ( list_is_singular ( &images ) ? NULL : &efi_file_initrd.load );
 	if ( ( rc = efi_file_path_install ( &efi_file_initrd_path.vendor.Header,
 					    load ) ) != 0 ) {
 		goto err_initrd;

src/interface/efi/efi_settings.c

@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2023 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 );
+
+/**
+ * @file
+ *
+ * EFI variable settings
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/settings.h>
+#include <ipxe/init.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/Guid/GlobalVariable.h>
+
+/** An EFI variable settings block */
+struct efivar_settings {
+	/** Settings block */
+	struct settings settings;
+	/** Vendor GUID */
+	EFI_GUID guid;
+};
+
+/** EFI settings scope */
+static const struct settings_scope efivar_scope;
+
+/**
+ * Check applicability of EFI variable setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting
+ * @ret applies		Setting applies within this settings block
+ */
+static int efivar_applies ( struct settings *settings __unused,
+			    const struct setting *setting ) {
+
+	return ( setting->scope == &efivar_scope );
+}
+
+/**
+ * Fetch value of EFI variable setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to fetch
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret len		Length of setting data, or negative error
+ */
+static int efivar_fetch ( struct settings *settings, struct setting *setting,
+			  void *data, size_t len ) {
+	EFI_RUNTIME_SERVICES *rs = efi_systab->RuntimeServices;
+	struct efivar_settings *efivars =
+		container_of ( settings, struct efivar_settings, settings );
+	size_t name_len = strlen ( setting->name );
+	CHAR16 wname[ name_len + 1 /* wNUL */ ];
+	UINT32 attrs;
+	UINTN size;
+	void *buf;
+	unsigned int i;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Convert name to UCS-2 */
+	for ( i = 0 ; i <= name_len ; i++ )
+		wname[i] = setting->name[i];
+
+	/* Get variable length */
+	size = 0;
+	efirc = rs->GetVariable ( wname, &efivars->guid, &attrs, &size, NULL );
+	if ( ( efirc != 0 ) && ( efirc != EFI_BUFFER_TOO_SMALL ) ) {
+		rc = -EEFI ( efirc );
+		DBGC ( efivars, "EFIVAR %s:%s not present: %s\n",
+		       efi_guid_ntoa ( &efivars->guid ), setting->name,
+		       strerror ( rc ) );
+		goto err_len;
+	}
+
+	/* Allocate temporary buffer, since GetVariable() is not
+	 * guaranteed to return partial data for an underlength
+	 * buffer.
+	 */
+	buf = malloc ( size );
+	if ( ! buf ) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+
+	/* Get variable value */
+	if ( ( efirc = rs->GetVariable ( wname, &efivars->guid, &attrs, &size,
+					 buf ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( efivars, "EFIVAR %s:%s could not get %zd bytes: %s\n",
+		       efi_guid_ntoa ( &efivars->guid ), setting->name,
+		       ( ( size_t ) size ), strerror ( rc ) );
+		goto err_get;
+	}
+	DBGC ( efivars, "EFIVAR %s:%s:\n", efi_guid_ntoa ( &efivars->guid ),
+	       setting->name );
+	DBGC_HDA ( efivars, 0, buf, size );
+
+	/* Return setting value */
+	if ( len > size )
+		len = size;
+	memcpy ( data, buf, len );
+	if ( ! setting->type )
+		setting->type = &setting_type_hex;
+
+	/* Free temporary buffer */
+	free ( buf );
+
+	return size;
+
+ err_get:
+	free ( buf );
+ err_alloc:
+ err_len:
+	return rc;
+}
+
+/** EFI variable settings operations */
+static struct settings_operations efivar_operations = {
+	.applies = efivar_applies,
+	.fetch = efivar_fetch,
+};
+
+/** Well-known EFI variable settings blocks */
+static struct efivar_settings efivar_settings[] = {
+	{ .settings = { .name = "efi" }, .guid = EFI_GLOBAL_VARIABLE },
+};
+
+/**
+ * Initialise EFI variable settings
+ *
+ */
+static void efivar_init ( void ) {
+	struct efivar_settings *efivars;
+	const char *name;
+	unsigned int i;
+	int rc;
+
+	/* Register all settings blocks */
+	for ( i = 0 ; i < ( sizeof ( efivar_settings ) /
+			    sizeof ( efivar_settings[0] ) ) ; i++ ) {
+
+		/* Initialise settings block */
+		efivars = &efivar_settings[i];
+		settings_init ( &efivars->settings, &efivar_operations, NULL,
+				&efivar_scope );
+
+		/* Register settings block */
+		name = efivars->settings.name;
+		if ( ( rc = register_settings ( &efivars->settings, NULL,
+						name ) ) != 0 ) {
+			DBGC ( &efivar_settings, "EFIVAR could not register "
+			       "%s: %s\n", name, strerror ( rc ) );
+			/* Continue trying to register remaining blocks */
+		}
+	}
+}
+
+/** EFI variable settings initialiser */
+struct init_fn efivar_init_fn __init_fn ( INIT_NORMAL ) = {
+	.initialise = efivar_init,
+};

src/net/netdev_settings.c

@@ -453,10 +453,11 @@ static int apply_netdev_settings ( void ) {
 			       netdev->name, mtu );
 		}
 
-		/* Reset network device if MTU has increased */
+		/* Close and reopen network device if MTU has increased */
 		if ( netdev_is_open ( netdev ) && ( mtu > old_mtu ) ) {
-			if ( ( rc = netdev_reset ( netdev ) ) != 0 ) {
-				DBGC ( netdev, "NETDEV %s could not reset: "
+			netdev_close ( netdev );
+			if ( ( rc = netdev_open ( netdev ) ) != 0 ) {
+				DBGC ( netdev, "NETDEV %s could not reopen: "
 				       "%s\n", netdev->name, strerror ( rc ) );
 				return rc;
 			}

src/net/netdevice.c

@@ -612,23 +612,6 @@ static void netdev_rx_flush ( struct net_device *netdev ) {
 	}
 }
 
-/**
- * Flush device's transmit and receive queues
- *
- * @v netdev		Network device
- */
-static void netdev_flush ( struct net_device *netdev ) {
-
-	/* Sanity check */
-	assert ( ! ( netdev->state & NETDEV_OPEN ) );
-
-	/* Flush TX queue */
-	netdev_tx_flush ( netdev );
-
-	/* Flush RX queue */
-	netdev_rx_flush ( netdev );
-}
-
 /**
  * Finish network device configuration
  *
@@ -674,7 +657,8 @@ static void free_netdev ( struct refcnt *refcnt ) {
 		container_of ( refcnt, struct net_device, refcnt );
 
 	stop_timer ( &netdev->link_block );
-	netdev_flush ( netdev );
+	netdev_tx_flush ( netdev );
+	netdev_rx_flush ( netdev );
 	clear_settings ( netdev_settings ( netdev ) );
 	free ( netdev );
 }
@@ -896,47 +880,8 @@ void netdev_close ( struct net_device *netdev ) {
 	netdev->op->close ( netdev );
 
 	/* Flush TX and RX queues */
-	netdev_flush ( netdev );
-}
-
-/**
- * Reset transmit and receive queues
- *
- * @v netdev		Network device
- * @ret rc		Return status code
- */
-int netdev_reset ( struct net_device *netdev ) {
-	int rc;
-
-	/* Do nothing unless device is open */
-	if ( ! ( netdev->state & NETDEV_OPEN ) )
-		return 0;
-
-	DBGC ( netdev, "NETDEV %s resetting\n", netdev->name );
-
-	/* Mark as closed */
-	netdev->state &= ~NETDEV_OPEN;
-
-	/* Close the device */
-	netdev->op->close ( netdev );
-
-	/* Flush TX and RX queues */
-	netdev_flush ( netdev );
-
-	/* Mark as opened */
-	netdev->state |= NETDEV_OPEN;
-
-	/* Reopen device */
-	if ( ( rc = netdev->op->open ( netdev ) ) != 0 )
-		goto err;
-
-	return 0;
-
- err:
-	netdev->state &= ~NETDEV_OPEN;
-	list_del ( &netdev->open_list );
-	netdev_notify ( netdev );
-	return rc;
+	netdev_tx_flush ( netdev );
+	netdev_rx_flush ( netdev );
 }
 
 /**

src/net/udp/dhcp.c

@@ -601,12 +601,6 @@ static void dhcp_request_rx ( struct dhcp_session *dhcp,
 		return;
 	}
 
-	/* Unregister any existing ProxyDHCP or PXEBS settings */
-	if ( ( settings = find_settings ( PROXYDHCP_SETTINGS_NAME ) ) != NULL )
-		unregister_settings ( settings );
-	if ( ( settings = find_settings ( PXEBS_SETTINGS_NAME ) ) != NULL )
-		unregister_settings ( settings );
-
 	/* Perform ProxyDHCP if applicable */
 	if ( dhcp->proxy_offer /* Have ProxyDHCP offer */ &&
 	     ( ! dhcp->no_pxedhcp ) /* ProxyDHCP not disabled */ ) {