8 files changed, 564 insertions, 155 deletions

diff --git a/src/interface/efi/efi_autoexec.c b/src/interface/efi/efi_autoexec.c
index 88eb379bb..79d4a4caf 100644
--- a/src/interface/efi/efi_autoexec.c
+++ b/src/interface/efi/efi_autoexec.c
@@ -24,11 +24,14 @@
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <string.h>
+#include <stdlib.h>
 #include <errno.h>
 #include <ipxe/image.h>
 #include <ipxe/init.h>
+#include <ipxe/in.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_autoexec.h>
+#include <ipxe/efi/Protocol/PxeBaseCode.h>
 #include <ipxe/efi/Protocol/SimpleFileSystem.h>
 #include <ipxe/efi/Guid/FileInfo.h>
 
@@ -39,10 +42,10 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  */
 
 /** Autoexec script filename */
-#define AUTOEXEC_FILENAME L"autoexec.ipxe"
+static wchar_t efi_autoexec_wname[] = L"autoexec.ipxe";
 
 /** Autoexec script image name */
-#define AUTOEXEC_NAME "autoexec.ipxe"
+static char efi_autoexec_name[] = "autoexec.ipxe";
 
 /** Autoexec script (if any) */
 static void *efi_autoexec;
@@ -51,21 +54,21 @@ static void *efi_autoexec;
 static size_t efi_autoexec_len;
 
 /**
- * Load autoexec script
+ * Load autoexec script from filesystem
  *
  * @v device		Device handle
  * @ret rc		Return status code
  */
-int efi_autoexec_load ( EFI_HANDLE device ) {
+static int efi_autoexec_filesystem ( EFI_HANDLE device ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	static wchar_t name[] = AUTOEXEC_FILENAME;
 	union {
 		void *interface;
 		EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
 	} u;
 	struct {
 		EFI_FILE_INFO info;
-		CHAR16 name[ sizeof ( name ) / sizeof ( name[0] ) ];
+		CHAR16 name[ sizeof ( efi_autoexec_wname ) /
+			     sizeof ( efi_autoexec_wname[0] ) ];
 	} info;
 	EFI_FILE_PROTOCOL *root;
 	EFI_FILE_PROTOCOL *file;
@@ -74,10 +77,6 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 	EFI_STATUS efirc;
 	int rc;
 
-	/* Sanity check */
-	assert ( efi_autoexec == NULL );
-	assert ( efi_autoexec_len == 0 );
-
 	/* Open simple file system protocol */
 	if ( ( efirc = bs->OpenProtocol ( device,
 					  &efi_simple_file_system_protocol_guid,
@@ -99,11 +98,12 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 	}
 
 	/* Open autoexec script */
-	if ( ( efirc = root->Open ( root, &file, name,
+	if ( ( efirc = root->Open ( root, &file, efi_autoexec_wname,
 				    EFI_FILE_MODE_READ, 0 ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( device, "EFI %s has no %ls: %s\n",
-		       efi_handle_name ( device ), name, strerror ( rc ) );
+		       efi_handle_name ( device ), efi_autoexec_wname,
+		       strerror ( rc ) );
 		goto err_open;
 	}
 
@@ -113,7 +113,8 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 				       &info ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( device, "EFI %s could not get %ls info: %s\n",
-		       efi_handle_name ( device ), name, strerror ( rc ) );
+		       efi_handle_name ( device ), efi_autoexec_wname,
+		       strerror ( rc ) );
 		goto err_getinfo;
 	}
 	size = info.info.FileSize;
@@ -122,7 +123,7 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 	if ( ! size ) {
 		rc = -EINVAL;
 		DBGC ( device, "EFI %s has zero-length %ls\n",
-		       efi_handle_name ( device ), name );
+		       efi_handle_name ( device ), efi_autoexec_wname );
 		goto err_empty;
 	}
 
@@ -131,7 +132,8 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 					  &data ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( device, "EFI %s could not allocate %ls: %s\n",
-		       efi_handle_name ( device ), name, strerror ( rc ) );
+		       efi_handle_name ( device ), efi_autoexec_wname,
+		       strerror ( rc ) );
 		goto err_alloc;
 	}
 
@@ -139,7 +141,8 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 	if ( ( efirc = file->Read ( file, &size, data ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( device, "EFI %s could not read %ls: %s\n",
-		       efi_handle_name ( device ), name, strerror ( rc ) );
+		       efi_handle_name ( device ), efi_autoexec_wname,
+		       strerror ( rc ) );
 		goto err_read;
 	}
 
@@ -148,7 +151,7 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 	efi_autoexec_len = size;
 	data = NULL;
 	DBGC ( device, "EFI %s found %ls\n",
-	       efi_handle_name ( device ), name );
+	       efi_handle_name ( device ), efi_autoexec_wname );
 
 	/* Success */
 	rc = 0;
@@ -170,13 +173,205 @@ int efi_autoexec_load ( EFI_HANDLE device ) {
 }
 
 /**
+ * Load autoexec script from TFTP server
+ *
+ * @v device		Device handle
+ * @ret rc		Return status code
+ */
+static int efi_autoexec_tftp ( EFI_HANDLE device ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	union {
+		void *interface;
+		EFI_PXE_BASE_CODE_PROTOCOL *pxe;
+	} u;
+	EFI_PXE_BASE_CODE_MODE *mode;
+	EFI_PXE_BASE_CODE_PACKET *packet;
+	union {
+		struct in_addr in;
+		EFI_IP_ADDRESS ip;
+	} server;
+	size_t filename_max;
+	char *filename;
+	char *sep;
+	UINT64 size;
+	VOID *data;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Open PXE base code protocol */
+	if ( ( efirc = bs->OpenProtocol ( device,
+					  &efi_pxe_base_code_protocol_guid,
+					  &u.interface, efi_image_handle,
+					  device,
+					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s has no PXE base code instance: %s\n",
+		       efi_handle_name ( device ), strerror ( rc ) );
+		goto err_pxe;
+	}
+
+	/* Do not attempt to parse DHCPv6 packets */
+	mode = u.pxe->Mode;
+	if ( mode->UsingIpv6 ) {
+		rc = -ENOTSUP;
+		DBGC ( device, "EFI %s has IPv6 PXE base code\n",
+		       efi_handle_name ( device ) );
+		goto err_ipv6;
+	}
+
+	/* Identify relevant reply packet */
+	if ( mode->PxeReplyReceived &&
+	     mode->PxeReply.Dhcpv4.BootpBootFile[0] ) {
+		/* Use boot filename if present in PXE reply */
+		DBGC ( device, "EFI %s using PXE reply filename\n",
+		       efi_handle_name ( device ) );
+		packet = &mode->PxeReply;
+	} else if ( mode->DhcpAckReceived &&
+		    mode->DhcpAck.Dhcpv4.BootpBootFile[0] ) {
+		/* Otherwise, use boot filename if present in DHCPACK */
+		DBGC ( device, "EFI %s using DHCPACK filename\n",
+		       efi_handle_name ( device ) );
+		packet = &mode->DhcpAck;
+	} else if ( mode->ProxyOfferReceived &&
+		    mode->ProxyOffer.Dhcpv4.BootpBootFile[0] ) {
+		/* Otherwise, use boot filename if present in ProxyDHCPOFFER */
+		DBGC ( device, "EFI %s using ProxyDHCPOFFER filename\n",
+		       efi_handle_name ( device ) );
+		packet = &mode->ProxyOffer;
+	} else {
+		/* No boot filename available */
+		rc = -ENOENT;
+		DBGC ( device, "EFI %s has no PXE boot filename\n",
+		       efi_handle_name ( device ) );
+		goto err_packet;
+	}
+
+	/* Allocate filename */
+	filename_max = ( sizeof ( packet->Dhcpv4.BootpBootFile )
+			 + ( sizeof ( efi_autoexec_name ) - 1 /* NUL */ )
+			 + 1 /* NUL */ );
+	filename = zalloc ( filename_max );
+	if ( ! filename ) {
+		rc = -ENOMEM;
+		goto err_filename;
+	}
+
+	/* Extract next-server address and boot filename */
+	memset ( &server, 0, sizeof ( server ) );
+	memcpy ( &server.in, packet->Dhcpv4.BootpSiAddr,
+		 sizeof ( server.in ) );
+	memcpy ( filename, packet->Dhcpv4.BootpBootFile,
+		 sizeof ( packet->Dhcpv4.BootpBootFile ) );
+
+	/* Update filename to autoexec script name */
+	sep = strrchr ( filename, '/' );
+	if ( ! sep )
+		sep = strrchr ( filename, '\\' );
+	if ( ! sep )
+		sep = ( filename - 1 );
+	strcpy ( ( sep + 1 ), efi_autoexec_name );
+
+	/* Get file size */
+	if ( ( efirc = u.pxe->Mtftp ( u.pxe,
+				      EFI_PXE_BASE_CODE_TFTP_GET_FILE_SIZE,
+				      NULL, FALSE, &size, NULL, &server.ip,
+				      ( ( UINT8 * ) filename ), NULL,
+				      FALSE ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not get size of %s:%s: %s\n",
+		       efi_handle_name ( device ), inet_ntoa ( server.in ),
+		       filename, strerror ( rc ) );
+		goto err_size;
+	}
+
+	/* Ignore zero-length files */
+	if ( ! size ) {
+		rc = -EINVAL;
+		DBGC ( device, "EFI %s has zero-length %s:%s\n",
+		       efi_handle_name ( device ), inet_ntoa ( server.in ),
+		       filename );
+		goto err_empty;
+	}
+
+	/* Allocate temporary copy */
+	if ( ( efirc = bs->AllocatePool ( EfiBootServicesData, size,
+					  &data ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not allocate %s:%s: %s\n",
+		       efi_handle_name ( device ), inet_ntoa ( server.in ),
+		       filename, strerror ( rc ) );
+		goto err_alloc;
+	}
+
+	/* Download file */
+	if ( ( efirc = u.pxe->Mtftp ( u.pxe, EFI_PXE_BASE_CODE_TFTP_READ_FILE,
+				      data, FALSE, &size, NULL, &server.ip,
+				      ( ( UINT8 * ) filename ), NULL,
+				      FALSE ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not download %s:%s: %s\n",
+		       efi_handle_name ( device ), inet_ntoa ( server.in ),
+		       filename, strerror ( rc ) );
+		goto err_download;
+	}
+
+	/* Record autoexec script */
+	efi_autoexec = data;
+	efi_autoexec_len = size;
+	data = NULL;
+	DBGC ( device, "EFI %s found %s:%s\n", efi_handle_name ( device ),
+	       inet_ntoa ( server.in ), filename );
+
+	/* Success */
+	rc = 0;
+
+ err_download:
+	if ( data )
+		bs->FreePool ( data );
+ err_alloc:
+ err_empty:
+ err_size:
+	free ( filename );
+ err_filename:
+ err_packet:
+ err_ipv6:
+	bs->CloseProtocol ( device, &efi_pxe_base_code_protocol_guid,
+			    efi_image_handle, device );
+ err_pxe:
+	return rc;
+}
+
+/**
+ * Load autoexec script
+ *
+ * @v device		Device handle
+ * @ret rc		Return status code
+ */
+int efi_autoexec_load ( EFI_HANDLE device ) {
+	int rc;
+
+	/* Sanity check */
+	assert ( efi_autoexec == NULL );
+	assert ( efi_autoexec_len == 0 );
+
+	/* Try loading from file system, if supported */
+	if ( ( rc = efi_autoexec_filesystem ( device ) ) == 0 )
+		return 0;
+
+	/* Try loading via TFTP, if supported */
+	if ( ( rc = efi_autoexec_tftp ( device ) ) == 0 )
+		return 0;
+
+	return -ENOENT;
+}
+
+/**
  * Register autoexec script
  *
  */
 static void efi_autoexec_startup ( void ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE device = efi_loaded_image->DeviceHandle;
-	const char *name = AUTOEXEC_NAME;
 	struct image *image;
 
 	/* Do nothing if we have no autoexec script */
@@ -184,15 +379,16 @@ static void efi_autoexec_startup ( void ) {
 		return;
 
 	/* Create autoexec image */
-	image = image_memory ( name, virt_to_user ( efi_autoexec ),
+	image = image_memory ( efi_autoexec_name,
+			       virt_to_user ( efi_autoexec ),
 			       efi_autoexec_len );
 	if ( ! image ) {
 		DBGC ( device, "EFI %s could not create %s\n",
-		       efi_handle_name ( device ), name );
+		       efi_handle_name ( device ), efi_autoexec_name );
 		return;
 	}
 	DBGC ( device, "EFI %s registered %s\n",
-	       efi_handle_name ( device ), name );
+	       efi_handle_name ( device ), efi_autoexec_name );
 
 	/* Free temporary copy */
 	bs->FreePool ( efi_autoexec );
diff --git a/src/interface/efi/efi_console.c b/src/interface/efi/efi_console.c
index 98ebbf3ac..04bbd9e0c 100644
--- a/src/interface/efi/efi_console.c
+++ b/src/interface/efi/efi_console.c
@@ -26,7 +26,9 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/Protocol/ConsoleControl/ConsoleControl.h>
 #include <ipxe/ansiesc.h>
+#include <ipxe/utf8.h>
 #include <ipxe/console.h>
+#include <ipxe/keymap.h>
 #include <ipxe/init.h>
 #include <config/console.h>
 
@@ -54,8 +56,6 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 #define ATTR_DEFAULT		ATTR_FCOL_WHITE
 
-#define CTRL_MASK		0x1f
-
 /* Set default console usage if applicable */
 #if ! ( defined ( CONSOLE_EFI ) && CONSOLE_EXPLICIT ( CONSOLE_EFI ) )
 #undef CONSOLE_EFI
@@ -202,6 +202,9 @@ static struct ansiesc_context efi_ansiesc_ctx = {
 	.handlers = efi_ansiesc_handlers,
 };
 
+/** EFI console UTF-8 accumulator */
+static struct utf8_accumulator efi_utf8_acc;
+
 /**
  * Print a character to EFI console
  *
@@ -209,13 +212,25 @@ static struct ansiesc_context efi_ansiesc_ctx = {
  */
 static void efi_putchar ( int character ) {
 	EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *conout = efi_systab->ConOut;
-	wchar_t wstr[] = { character, 0 };
+	wchar_t wstr[2];
 
 	/* Intercept ANSI escape sequences */
 	character = ansiesc_process ( &efi_ansiesc_ctx, character );
 	if ( character < 0 )
 		return;
 
+	/* Accumulate Unicode characters */
+	character = utf8_accumulate ( &efi_utf8_acc, character );
+	if ( character == 0 )
+		return;
+
+	/* Treat unrepresentable (non-UCS2) characters as invalid */
+	if ( character & ~( ( wchar_t ) -1UL ) )
+		character = UTF8_INVALID;
+
+	/* Output character */
+	wstr[0] = character;
+	wstr[1] = L'\0';
 	conout->OutputString ( conout, wstr );
 }
 
@@ -285,6 +300,9 @@ static int efi_getchar ( void ) {
 	EFI_SIMPLE_TEXT_INPUT_PROTOCOL *conin = efi_systab->ConIn;
 	EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL *conin_ex = efi_conin_ex;
 	const char *ansi_seq;
+	unsigned int character;
+	unsigned int shift;
+	unsigned int toggle;
 	EFI_KEY_DATA key;
 	EFI_STATUS efirc;
 	int rc;
@@ -317,16 +335,37 @@ static int efi_getchar ( void ) {
 	       key.KeyState.KeyToggleState, key.Key.UnicodeChar,
 	       key.Key.ScanCode );
 
-	/* Translate Ctrl-<key> */
-	if ( ( key.KeyState.KeyShiftState & EFI_SHIFT_STATE_VALID ) &&
-	     ( key.KeyState.KeyShiftState & ( EFI_LEFT_CONTROL_PRESSED |
-					      EFI_RIGHT_CONTROL_PRESSED ) ) ) {
-		key.Key.UnicodeChar &= CTRL_MASK;
-	}
+	/* If key has a Unicode representation, remap and return it.
+	 * There is unfortunately no way to avoid remapping the
+	 * numeric keypad, since EFI destroys the scan code
+	 * information that would allow us to differentiate between
+	 * main keyboard and numeric keypad.
+	 */
+	if ( ( character = key.Key.UnicodeChar ) != 0 ) {
+
+		/* Apply shift state */
+		shift = key.KeyState.KeyShiftState;
+		if ( shift & EFI_SHIFT_STATE_VALID ) {
+			if ( shift & ( EFI_LEFT_CONTROL_PRESSED |
+				       EFI_RIGHT_CONTROL_PRESSED ) ) {
+				character |= KEYMAP_CTRL;
+			}
+			if ( shift & EFI_RIGHT_ALT_PRESSED ) {
+				character |= KEYMAP_ALTGR;
+			}
+		}
 
-	/* If key has a Unicode representation, return it */
-	if ( key.Key.UnicodeChar )
-		return key.Key.UnicodeChar;
+		/* Apply toggle state */
+		toggle = key.KeyState.KeyToggleState;
+		if ( toggle & EFI_TOGGLE_STATE_VALID ) {
+			if ( toggle & EFI_CAPS_LOCK_ACTIVE ) {
+				character |= KEYMAP_CAPSLOCK_REDO;
+			}
+		}
+
+		/* Remap and return key */
+		return key_remap ( character );
+	}
 
 	/* Otherwise, check for a special key that we know about */
 	if ( ( ansi_seq = scancode_to_ansi_seq ( key.Key.ScanCode ) ) ) {
diff --git a/src/interface/efi/efi_entropy.c b/src/interface/efi/efi_entropy.c
index b7cb6a40c..71341d9d4 100644
--- a/src/interface/efi/efi_entropy.c
+++ b/src/interface/efi/efi_entropy.c
@@ -109,8 +109,8 @@ static void efi_entropy_disable ( void ) {
 	/* Close timer tick event */
 	bs->CloseEvent ( tick );
 
-	/* Return to TPL_CALLBACK */
-	bs->RaiseTPL ( TPL_CALLBACK );
+	/* Return to internal TPL */
+	bs->RaiseTPL ( efi_internal_tpl );
 }
 
 /**
diff --git a/src/interface/efi/efi_fbcon.c b/src/interface/efi/efi_fbcon.c
index 1ea25df04..e3c4d001d 100644
--- a/src/interface/efi/efi_fbcon.c
+++ b/src/interface/efi/efi_fbcon.c
@@ -62,6 +62,12 @@ struct console_driver efi_console __attribute__ (( weak ));
 #define CONSOLE_EFIFB ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
 #endif
 
+/** Number of ASCII glyphs in cache */
+#define EFIFB_ASCII 128
+
+/** Number of dynamic non-ASCII glyphs in cache */
+#define EFIFB_DYNAMIC 32
+
 /* Forward declaration */
 struct console_driver efifb_console __console_driver;
 
@@ -84,22 +90,159 @@ struct efifb {
 	struct fbcon_colour_map map;
 	/** Font definition */
 	struct fbcon_font font;
-	/** Character glyphs */
+	/** Character glyph cache */
 	userptr_t glyphs;
+	/** Dynamic characters in cache */
+	unsigned int dynamic[EFIFB_DYNAMIC];
+	/** Next dynamic character cache entry to evict */
+	unsigned int next;
 };
 
 /** The EFI frame buffer */
 static struct efifb efifb;
 
 /**
- * Get character glyph
+ * Draw character glyph
  *
  * @v character		Character
+ * @v index		Index within glyph cache
+ * @v toggle		Bits to toggle in each bitmask
+ * @ret height		Character height, or negative error
+ */
+static int efifb_draw ( unsigned int character, unsigned int index,
+			unsigned int toggle ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	EFI_IMAGE_OUTPUT *blt;
+	EFI_GRAPHICS_OUTPUT_BLT_PIXEL *pixel;
+	unsigned int height;
+	unsigned int x;
+	unsigned int y;
+	uint8_t bitmask;
+	size_t offset;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Clear existing glyph */
+	offset = ( index * efifb.font.height );
+	memset_user ( efifb.glyphs, offset, 0, efifb.font.height );
+
+	/* Get glyph */
+	blt = NULL;
+	if ( ( efirc = efifb.hiifont->GetGlyph ( efifb.hiifont, character,
+						 NULL, &blt, NULL ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( &efifb, "EFIFB could not get glyph %#02x: %s\n",
+		       character, strerror ( rc ) );
+		goto err_get;
+	}
+	assert ( blt != NULL );
+
+	/* Sanity check */
+	if ( blt->Width > 8 ) {
+		DBGC ( &efifb, "EFIFB glyph %#02x invalid width %d\n",
+		       character, blt->Width );
+		rc = -EINVAL;
+		goto err_width;
+	}
+
+	/* Convert glyph to bitmap */
+	pixel = blt->Image.Bitmap;
+	height = blt->Height;
+	for ( y = 0 ; ( ( y < height ) && ( y < efifb.font.height ) ) ; y++ ) {
+		bitmask = 0;
+		for ( x = 0 ; x < blt->Width ; x++ ) {
+			bitmask = rol8 ( bitmask, 1 );
+			if ( pixel->Blue || pixel->Green || pixel->Red )
+				bitmask |= 0x01;
+			pixel++;
+		}
+		bitmask ^= toggle;
+		copy_to_user ( efifb.glyphs, offset++, &bitmask,
+			       sizeof ( bitmask ) );
+	}
+
+	/* Free glyph */
+	bs->FreePool ( blt );
+
+	return height;
+
+ err_width:
+	bs->FreePool ( blt );
+ err_get:
+	return rc;
+}
+
+/**
+ * Draw "unknown character" glyph
+ *
+ * @v index		Index within glyph cache
+ * @ret rc		Return status code
+ */
+static int efifb_draw_unknown ( unsigned int index ) {
+
+	/* Draw an inverted '?' glyph */
+	return efifb_draw ( '?', index, -1U );
+}
+
+/**
+ * Get dynamic glyph index
+ *
+ * @v character		Unicode character
+ * @ret index		Glyph cache index
+ */
+static unsigned int efifb_dynamic ( unsigned int character ) {
+	unsigned int dynamic;
+	unsigned int index;
+	unsigned int i;
+	int height;
+
+	/* Search existing cached entries */
+	for ( i = 0 ; i < EFIFB_DYNAMIC ; i++ ) {
+		if ( character == efifb.dynamic[i] )
+			return ( EFIFB_ASCII + i );
+	}
+
+	/* Overwrite the oldest cache entry */
+	dynamic = ( efifb.next++ % EFIFB_DYNAMIC );
+	index = ( EFIFB_ASCII + dynamic );
+	DBGC2 ( &efifb, "EFIFB dynamic %#02x is glyph %#02x\n",
+		dynamic, character );
+
+	/* Draw glyph */
+	height = efifb_draw ( character, index, 0 );
+	if ( height < 0 )
+		efifb_draw_unknown ( index );
+
+	/* Record cached character */
+	efifb.dynamic[dynamic] = character;
+
+	return index;
+}
+
+/**
+ * Get character glyph
+ *
+ * @v character		Unicode character
  * @v glyph		Character glyph to fill in
  */
 static void efifb_glyph ( unsigned int character, uint8_t *glyph ) {
-	size_t offset = ( character * efifb.font.height );
+	unsigned int index;
+	size_t offset;
+
+	/* Identify glyph */
+	if ( character < EFIFB_ASCII ) {
+
+		/* ASCII character: use fixed cache entry */
+		index = character;
+
+	} else {
+
+		/* Non-ASCII character: use dynamic glyph cache */
+		index = efifb_dynamic ( character );
+	}
 
+	/* Copy cached glyph */
+	offset = ( index * efifb.font.height );
 	copy_from_user ( glyph, efifb.glyphs, offset, efifb.font.height );
 }
 
@@ -109,16 +252,10 @@ static void efifb_glyph ( unsigned int character, uint8_t *glyph ) {
  * @ret rc		Return status code
  */
 static int efifb_glyphs ( void ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	EFI_IMAGE_OUTPUT *blt;
-	EFI_GRAPHICS_OUTPUT_BLT_PIXEL *pixel;
-	size_t offset;
-	size_t len;
-	uint8_t bitmask;
 	unsigned int character;
-	unsigned int x;
-	unsigned int y;
-	EFI_STATUS efirc;
+	int height;
+	int max;
+	size_t len;
 	int rc;
 
 	/* Get font height.  The GetFontInfo() call nominally returns
@@ -128,38 +265,32 @@ static int efifb_glyphs ( void ) {
 	 * height.
 	 */
 	efifb.font.height = 0;
-	for ( character = 0 ; character < 256 ; character++ ) {
+	max = 0;
+	for ( character = 0 ; character < EFIFB_ASCII ; character++ ) {
 
 		/* Skip non-printable characters */
 		if ( ! isprint ( character ) )
 			continue;
 
 		/* Get glyph */
-		blt = NULL;
-		if ( ( efirc = efifb.hiifont->GetGlyph ( efifb.hiifont,
-							 character, NULL, &blt,
-							 NULL ) ) != 0 ) {
-			rc = -EEFI ( efirc );
-			DBGC ( &efifb, "EFIFB could not get glyph %d: %s\n",
-			       character, strerror ( rc ) );
-			continue;
+		height = efifb_draw ( character, 0, 0 );
+		if ( height < 0 ) {
+			rc = height;
+			goto err_height;
 		}
-		assert ( blt != NULL );
 
 		/* Calculate maximum height */
-		if ( efifb.font.height < blt->Height )
-			efifb.font.height = blt->Height;
-
-		/* Free glyph */
-		bs->FreePool ( blt );
+		if ( max < height )
+			max = height;
 	}
-	if ( ! efifb.font.height ) {
+	if ( ! max ) {
 		DBGC ( &efifb, "EFIFB could not get font height\n" );
 		return -ENOENT;
 	}
+	efifb.font.height = max;
 
 	/* Allocate glyph data */
-	len = ( 256 * efifb.font.height * sizeof ( bitmask ) );
+	len = ( ( EFIFB_ASCII + EFIFB_DYNAMIC ) * efifb.font.height );
 	efifb.glyphs = umalloc ( len );
 	if ( ! efifb.glyphs ) {
 		rc = -ENOMEM;
@@ -168,60 +299,32 @@ static int efifb_glyphs ( void ) {
 	memset_user ( efifb.glyphs, 0, 0, len );
 
 	/* Get font data */
-	for ( character = 0 ; character < 256 ; character++ ) {
+	for ( character = 0 ; character < EFIFB_ASCII ; character++ ) {
 
 		/* Skip non-printable characters */
-		if ( ! isprint ( character ) )
-			continue;
-
-		/* Get glyph */
-		blt = NULL;
-		if ( ( efirc = efifb.hiifont->GetGlyph ( efifb.hiifont,
-							 character, NULL, &blt,
-							 NULL ) ) != 0 ) {
-			rc = -EEFI ( efirc );
-			DBGC ( &efifb, "EFIFB could not get glyph %d: %s\n",
-			       character, strerror ( rc ) );
-			continue;
-		}
-		assert ( blt != NULL );
-
-		/* Sanity check */
-		if ( blt->Width > 8 ) {
-			DBGC ( &efifb, "EFIFB glyph %d invalid width %d\n",
-			       character, blt->Width );
-			continue;
-		}
-		if ( blt->Height > efifb.font.height ) {
-			DBGC ( &efifb, "EFIFB glyph %d invalid height %d\n",
-			       character, blt->Height );
+		if ( ! isprint ( character ) ) {
+			efifb_draw_unknown ( character );
 			continue;
 		}
 
-		/* Convert glyph to bitmap */
-		pixel = blt->Image.Bitmap;
-		offset = ( character * efifb.font.height );
-		for ( y = 0 ; y < blt->Height ; y++ ) {
-			bitmask = 0;
-			for ( x = 0 ; x < blt->Width ; x++ ) {
-				bitmask = rol8 ( bitmask, 1 );
-				if ( pixel->Blue || pixel->Green || pixel->Red )
-					bitmask |= 0x01;
-				pixel++;
-			}
-			copy_to_user ( efifb.glyphs, offset++, &bitmask,
-				       sizeof ( bitmask ) );
+		/* Get glyph */
+		height = efifb_draw ( character, character, 0 );
+		if ( height < 0 ) {
+			rc = height;
+			goto err_draw;
 		}
-
-		/* Free glyph */
-		bs->FreePool ( blt );
 	}
 
+	/* Clear dynamic glyph character cache */
+	memset ( efifb.dynamic, 0, sizeof ( efifb.dynamic ) );
+
 	efifb.font.glyph = efifb_glyph;
 	return 0;
 
+ err_draw:
 	ufree ( efifb.glyphs );
  err_alloc:
+ err_height:
 	return rc;
 }
 
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index b7cac16e5..5d98f9ff7 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -47,6 +47,9 @@ EFI_DEVICE_PATH_PROTOCOL *efi_loaded_image_path;
  */
 EFI_SYSTEM_TABLE * _C2 ( PLATFORM, _systab );
 
+/** Internal task priority level */
+EFI_TPL efi_internal_tpl = TPL_CALLBACK;
+
 /** External task priority level */
 EFI_TPL efi_external_tpl = TPL_APPLICATION;
 
@@ -79,6 +82,17 @@ static EFI_STATUS EFIAPI efi_unload ( EFI_HANDLE image_handle );
 static EFIAPI void efi_shutdown_hook ( EFI_EVENT event __unused,
 				       void *context __unused ) {
 
+	/* This callback is invoked at TPL_NOTIFY in order to ensure
+	 * that we have an opportunity to shut down cleanly before
+	 * other shutdown hooks perform destructive operations such as
+	 * disabling the IOMMU.
+	 *
+	 * Modify the internal task priority level so that no code
+	 * attempts to raise from TPL_NOTIFY to TPL_CALLBACK (which
+	 * would trigger a fatal exception).
+	 */
+	efi_internal_tpl = TPL_NOTIFY;
+
 	/* Mark shutdown as being in progress, to indicate that large
 	 * parts of the system (e.g. timers) are no longer functional.
 	 */
@@ -273,7 +287,7 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 	 * bother doing so when ExitBootServices() is called.
 	 */
 	if ( ( efirc = bs->CreateEvent ( EVT_SIGNAL_EXIT_BOOT_SERVICES,
-					 TPL_CALLBACK, efi_shutdown_hook,
+					 TPL_NOTIFY, efi_shutdown_hook,
 					 NULL, &efi_shutdown_event ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( systab, "EFI could not create ExitBootServices event: "
@@ -316,9 +330,13 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 static EFI_STATUS EFIAPI efi_unload ( EFI_HANDLE image_handle __unused ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_SYSTEM_TABLE *systab = efi_systab;
+	struct efi_saved_tpl tpl;
 
 	DBGC ( systab, "EFI image unloading\n" );
 
+	/* Raise TPL */
+	efi_raise_tpl ( &tpl );
+
 	/* Shut down */
 	shutdown_exit();
 
@@ -336,6 +354,9 @@ static EFI_STATUS EFIAPI efi_unload ( EFI_HANDLE image_handle __unused ) {
 
 	DBGC ( systab, "EFI image unloaded\n" );
 
+	/* Restore TPL */
+	efi_restore_tpl ( &tpl );
+
 	return 0;
 }
 
@@ -366,7 +387,7 @@ __attribute__ (( noreturn )) void __stack_chk_fail ( void ) {
 }
 
 /**
- * Raise task priority level to TPL_CALLBACK
+ * Raise task priority level to internal level
  *
  * @v tpl		Saved TPL
  */
@@ -377,7 +398,7 @@ void efi_raise_tpl ( struct efi_saved_tpl *tpl ) {
 	tpl->previous = efi_external_tpl;
 
 	/* Raise TPL and record previous TPL as new external TPL */
-	tpl->current = bs->RaiseTPL ( TPL_CALLBACK );
+	tpl->current = bs->RaiseTPL ( efi_internal_tpl );
 	efi_external_tpl = tpl->current;
 }
 
diff --git a/src/interface/efi/efi_timer.c b/src/interface/efi/efi_timer.c
index 405cd3454..6427eb1d8 100644
--- a/src/interface/efi/efi_timer.c
+++ b/src/interface/efi/efi_timer.c
@@ -137,7 +137,7 @@ static unsigned long efi_currticks ( void ) {
 		efi_jiffies++;
 	} else {
 		bs->RestoreTPL ( efi_external_tpl );
-		bs->RaiseTPL ( TPL_CALLBACK );
+		bs->RaiseTPL ( efi_internal_tpl );
 	}
 
 	return ( efi_jiffies * ( TICKS_PER_SEC / EFI_JIFFIES_PER_SEC ) );
diff --git a/src/interface/efi/efi_watchdog.c b/src/interface/efi/efi_watchdog.c
index 7061f81d8..dcc9a5668 100644
--- a/src/interface/efi/efi_watchdog.c
+++ b/src/interface/efi/efi_watchdog.c
@@ -34,6 +34,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <string.h>
 #include <ipxe/retry.h>
 #include <ipxe/timer.h>
+#include <ipxe/init.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_watchdog.h>
 
@@ -80,3 +81,36 @@ static void efi_watchdog_expired ( struct retry_timer *timer,
 
 /** Watchdog holdoff timer */
 struct retry_timer efi_watchdog = TIMER_INIT ( efi_watchdog_expired );
+
+/**
+ * Disable watching when shutting down to boot an operating system
+ *
+ * @v booting		System is shutting down for OS boot
+ */
+static void efi_watchdog_shutdown ( int booting ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* If we are shutting down to boot an operating system, then
+	 * disable the boot services watchdog timer.  The UEFI
+	 * specification mandates that the platform firmware does this
+	 * as part of the ExitBootServices() call, but some platforms
+	 * (e.g. Hyper-V) are observed to occasionally forget to do
+	 * so, resulting in a reboot approximately five minutes after
+	 * starting the operating system.
+	 */
+	if ( booting &&
+	     ( ( efirc = bs->SetWatchdogTimer ( 0, 0, 0, NULL ) ) != 0 ) ) {
+		rc = -EEFI ( efirc );
+		DBGC ( &efi_watchdog, "EFI could not disable watchdog timer: "
+		       "%s\n", strerror ( rc ) );
+		/* Nothing we can do */
+	}
+}
+
+/** Watchdog startup/shutdown function */
+struct startup_fn efi_watchdog_startup_fn __startup_fn ( STARTUP_EARLY ) = {
+	.name = "efi_watchdog",
+	.shutdown = efi_watchdog_shutdown,
+};
diff --git a/src/interface/efi/efi_wrap.c b/src/interface/efi/efi_wrap.c
index 5c02a7ee1..5d5d2caee 100644
--- a/src/interface/efi/efi_wrap.c
+++ b/src/interface/efi/efi_wrap.c
@@ -196,6 +196,47 @@ static const char * efi_timer_delay ( EFI_TIMER_DELAY type ) {
 }
 
 /**
+ * Dump information about a loaded image
+ *
+ * @v handle		Image handle
+ */
+static void efi_dump_image ( EFI_HANDLE handle ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	union {
+		EFI_LOADED_IMAGE_PROTOCOL *image;
+		void *intf;
+	} loaded;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Open loaded image protocol */
+	if ( ( efirc = bs->OpenProtocol ( handle,
+					  &efi_loaded_image_protocol_guid,
+					  &loaded.intf, efi_image_handle, NULL,
+					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
+		rc = -EEFI ( efirc );
+		DBGC ( colour, "WRAP %s could not get loaded image protocol: "
+		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
+		return;
+	}
+
+	/* Dump image information */
+	DBGC ( colour, "WRAP %s at base %p has protocols:\n",
+	       efi_handle_name ( handle ), loaded.image->ImageBase );
+	DBGC_EFI_PROTOCOLS ( colour, handle );
+	DBGC ( colour, "WRAP %s parent", efi_handle_name ( handle ) );
+	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->ParentHandle ));
+	DBGC ( colour, "WRAP %s device", efi_handle_name ( handle ) );
+	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->DeviceHandle ));
+	DBGC ( colour, "WRAP %s file", efi_handle_name ( handle ) );
+	DBGC ( colour, " %s\n", efi_devpath_text ( loaded.image->FilePath ) );
+
+	/* Close loaded image protocol */
+	bs->CloseProtocol ( handle, &efi_loaded_image_protocol_guid,
+			    efi_image_handle, NULL );
+}
+
+/**
  * Wrap RaiseTPL()
  *
  */
@@ -655,9 +696,9 @@ efi_load_image_wrapper ( BOOLEAN boot_policy, EFI_HANDLE parent_image_handle,
 		DBGC ( colour, "%s ", efi_handle_name ( *image_handle ) );
 	DBGC ( colour, ") -> %p\n", retaddr );
 
-	/* Wrap the new image */
+	/* Dump information about loaded image */
 	if ( efirc == 0 )
-		efi_wrap ( *image_handle );
+		efi_dump_image ( *image_handle );
 
 	return efirc;
 }
@@ -735,11 +776,14 @@ efi_exit_boot_services_wrapper ( EFI_HANDLE image_handle, UINTN map_key ) {
 	void *retaddr = __builtin_return_address ( 0 );
 	EFI_STATUS efirc;
 
-	DBGC ( colour, "ExitBootServices ( %s, %#llx ) ",
+	DBGC ( colour, "ExitBootServices ( %s, %#llx ) -> %p\n",
 	       efi_handle_name ( image_handle ),
-	       ( ( unsigned long long ) map_key ) );
+	       ( ( unsigned long long ) map_key ), retaddr );
 	efirc = bs->ExitBootServices ( image_handle, map_key );
-	DBGC ( colour, "= %s -> %p\n", efi_status ( efirc ), retaddr );
+	if ( efirc != 0 ) {
+		DBGC ( colour, "ExitBootServices ( ... ) = %s -> %p\n",
+		       efi_status ( efirc ), retaddr );
+	}
 	return efirc;
 }
 
@@ -1129,12 +1173,11 @@ efi_create_event_ex_wrapper ( UINT32 type, EFI_TPL notify_tpl,
 }
 
 /**
- * Build table wrappers
+ * Build boot services table wrapper
  *
- * @ret systab		Wrapped system table
+ * @ret bs		Wrapped boot services table
  */
-EFI_SYSTEM_TABLE * efi_wrap_systab ( void ) {
-	static EFI_SYSTEM_TABLE efi_systab_wrapper;
+EFI_BOOT_SERVICES * efi_wrap_bs ( void ) {
 	static EFI_BOOT_SERVICES efi_bs_wrapper;
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 
@@ -1194,12 +1237,7 @@ EFI_SYSTEM_TABLE * efi_wrap_systab ( void ) {
 		= efi_uninstall_multiple_protocol_interfaces_wrapper;
 	efi_bs_wrapper.CreateEventEx	= efi_create_event_ex_wrapper;
 
-	/* Build system table wrapper */
-	memcpy ( &efi_systab_wrapper, efi_systab,
-		 sizeof ( efi_systab_wrapper ) );
-	efi_systab_wrapper.BootServices	= &efi_bs_wrapper;
-
-	return &efi_systab_wrapper;
+	return &efi_bs_wrapper;
 }
 
 /**
@@ -1208,42 +1246,20 @@ EFI_SYSTEM_TABLE * efi_wrap_systab ( void ) {
  * @v handle		Image handle
  */
 void efi_wrap ( EFI_HANDLE handle ) {
-	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_LOADED_IMAGE_PROTOCOL *image;
-		void *intf;
-	} loaded;
-	EFI_STATUS efirc;
-	int rc;
+	static EFI_SYSTEM_TABLE efi_systab_copy;
 
 	/* Do nothing unless debugging is enabled */
 	if ( ! DBG_LOG )
 		return;
 
-	/* Open loaded image protocol */
-	if ( ( efirc = bs->OpenProtocol ( handle,
-					  &efi_loaded_image_protocol_guid,
-					  &loaded.intf, efi_image_handle, NULL,
-					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
-		rc = -EEFI ( efirc );
-		DBGC ( colour, "WRAP %s could not get loaded image protocol: "
-		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
-		return;
+	/* Construct modified system table */
+	if ( efi_systab != &efi_systab_copy ) {
+		memcpy ( &efi_systab_copy, efi_systab,
+			 sizeof ( efi_systab_copy ) );
+		efi_systab->BootServices = efi_wrap_bs();
+		efi_systab = &efi_systab_copy;
 	}
 
-	/* Provide system table wrapper to image */
-	loaded.image->SystemTable = efi_wrap_systab();
-	DBGC ( colour, "WRAP %s at base %p has protocols:\n",
-	       efi_handle_name ( handle ), loaded.image->ImageBase );
-	DBGC_EFI_PROTOCOLS ( colour, handle );
-	DBGC ( colour, "WRAP %s parent", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->ParentHandle ));
-	DBGC ( colour, "WRAP %s device", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->DeviceHandle ));
-	DBGC ( colour, "WRAP %s file", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_devpath_text ( loaded.image->FilePath ) );
-
-	/* Close loaded image protocol */
-	bs->CloseProtocol ( handle, &efi_loaded_image_protocol_guid,
-			    efi_image_handle, NULL );
+	/* Dump image information */
+	efi_dump_image ( handle );
 }