[efi] Add efi_strerror()

EFI_STATUS is defined as an INTN, which maps to UINT32 (i.e. unsigned
int) on i386 and UINT64 (i.e. unsigned long) on x86_64.  This would
require a cast each time the error status is printed.

Add efi_strerror() to avoid this ickiness and simultaneously enable
prettier reporting of EFI status codes.

src/image/efi_image.c

 				       user_to_virt ( image->data, 0 ),
 				       image->len, &handle ) ) != 0 ) {
 		/* Not an EFI image */
-		DBGC ( image, "EFIIMAGE %p could not load: %x\n",
-		       image, efirc );
+		DBGC ( image, "EFIIMAGE %p could not load: %s\n",
+		       image, efi_strerror ( efirc ) );
 		return -ENOEXEC;
 	}
 
 	/* Start the image */
 	if ( ( efirc = bs->StartImage ( handle, &exit_data_size,
 					&exit_data ) ) != 0 ) {
-		DBGC ( image, "EFIIMAGE %p returned with status %x\n",
-		       image, efirc );
+		DBGC ( image, "EFIIMAGE %p returned with status %s\n",
+		       image, efi_strerror ( efirc ) );
 		goto done;
 	}
 
 				       user_to_virt ( image->data, 0 ),
 				       image->len, &handle ) ) != 0 ) {
 		/* Not an EFI image */
-		DBGC ( image, "EFIIMAGE %p could not load: %x\n",
-		       image, efirc );
+		DBGC ( image, "EFIIMAGE %p could not load: %s\n",
+		       image, efi_strerror ( efirc ) );
 		return -ENOEXEC;
 	}
 

src/include/gpxe/efi/efi.h

 extern EFI_HANDLE efi_image_handle;
 extern EFI_SYSTEM_TABLE *efi_systab;
 
+extern const char * efi_strerror ( EFI_STATUS efirc );
+
 #endif /* _EFI_H */

src/interface/efi/efi_console.c

 
 	/* Read key from real EFI console */
 	if ( ( efirc = conin->ReadKeyStroke ( conin, &key ) ) != 0 ) {
-		DBG ( "EFI could not read keystroke: %x\n", efirc );
+		DBG ( "EFI could not read keystroke: %s\n",
+		      efi_strerror ( efirc ) );
 		return 0;
 	}
 	DBG2 ( "EFI read key stroke with unicode %04x scancode %04x\n",

src/interface/efi/efi_io.c

 	if ( ( efirc = read ( cpu_io, efi_width ( size ),
 			      ( intptr_t ) io_addr, 1,
 			      ( void * ) &data ) ) != 0 ) {
-		DBG ( "EFI I/O read at %p failed: %x\n", io_addr, efirc );
+		DBG ( "EFI I/O read at %p failed: %s\n",
+		      io_addr, efi_strerror ( efirc ) );
 		return -1ULL;
 	}
 
 	if ( ( efirc = write ( cpu_io, efi_width ( size ),
 			       ( intptr_t ) io_addr, 1,
 			       ( void * ) &data ) ) != 0 ) {
-		DBG ( "EFI I/O write at %p failed: %x\n", io_addr, efirc );
+		DBG ( "EFI I/O write at %p failed: %s\n",
+		      io_addr, efi_strerror ( efirc ) );
 	}
 }
 
 	if ( ( efirc = read ( cpu_io, efi_width ( size ),
 			      ( intptr_t ) io_addr, count,
 			      ( void * ) data ) ) != 0 ) {
-		DBG ( "EFI I/O string read at %p failed: %x\n",
-		      io_addr, efirc );
+		DBG ( "EFI I/O string read at %p failed: %s\n",
+		      io_addr, efi_strerror ( efirc ) );
 	}
 }
 
 	if ( ( efirc = write ( cpu_io, efi_width ( size ),
 			       ( intptr_t ) io_addr, count,
 			       ( void * ) data ) ) != 0 ) {
-		DBG ( "EFI I/O write at %p failed: %x\n",
-		      io_addr, efirc );
+		DBG ( "EFI I/O write at %p failed: %s\n",
+		      io_addr, efi_strerror ( efirc ) );
 	}
 }
 

src/interface/efi/efi_pci.c

 					  efipci_address ( pci, location ), 1,
 					  value ) ) != 0 ) {
 		DBG ( "EFIPCI config read from %02x:%02x.%x offset %02lx "
-		      "failed: %x\n", pci->bus, PCI_SLOT ( pci->devfn ),
+		      "failed: %s\n", pci->bus, PCI_SLOT ( pci->devfn ),
 		      PCI_FUNC ( pci->devfn ), EFIPCI_OFFSET ( location ),
-		      efirc );
+		      efi_strerror ( efirc ) );
 		return -EIO;
 	}
 
 					   efipci_address ( pci, location ), 1,
 					   &value ) ) != 0 ) {
 		DBG ( "EFIPCI config write to %02x:%02x.%x offset %02lx "
-		      "failed: %x\n", pci->bus, PCI_SLOT ( pci->devfn ),
+		      "failed: %s\n", pci->bus, PCI_SLOT ( pci->devfn ),
 		      PCI_FUNC ( pci->devfn ), EFIPCI_OFFSET ( location ),
-		      efirc );
+		      efi_strerror ( efirc ) );
 		return -EIO;
 	}
 

src/interface/efi/efi_snp.c

 	if ( ( efirc = u.pci->GetLocation ( u.pci, &pci_segment, &pci_bus,
 					    &pci_dev, &pci_fn ) ) != 0 ) {
 		DBGC ( driver, "SNPDRV %p device %p could not get PCI "
-		       "location: %x\n", driver, device, efirc );
+		       "location: %s\n",
+		       driver, device, efi_strerror ( efirc ) );
 		goto out_no_pci_location;
 	}
 	DBGCP ( driver, "SNPDRV %p device %p is PCI %04x:%02x:%02x.%x\n",
 					  device,
 					  EFI_OPEN_PROTOCOL_GET_PROTOCOL))!=0){
 		DBGC ( driver, "SNPDRV %p device %p could not locate SNP: "
-		       "%x\n", driver, device, efirc );
+		       "%s\n", driver, device, efi_strerror ( efirc ) );
 		return NULL;
 	}
 
 	if ( ( efirc = bs->CreateEvent ( EVT_NOTIFY_WAIT, TPL_NOTIFY,
 					 efi_snp_wait_for_packet, snpdev,
 					 &snpdev->snp.WaitForPacket ) ) != 0 ){
-		DBGC ( snpdev, "SNPDEV %p could not create event: %x\n",
-		       snpdev, efirc );
+		DBGC ( snpdev, "SNPDEV %p could not create event: %s\n",
+		       snpdev, efi_strerror ( efirc ) );
 		goto err_create_event;
 	}
 
 	if ( ( efirc = bs->InstallProtocolInterface ( &device,
 				&efi_simple_network_protocol_guid,
 				EFI_NATIVE_INTERFACE, &snpdev->snp ) ) != 0 ) {
-		DBGC ( snpdev, "SNPDEV %p could not install protocol: %x\n",
-		       snpdev, efirc );
+		DBGC ( snpdev, "SNPDEV %p could not install protocol: %s\n",
+		       snpdev, efi_strerror ( efirc ) );
 		goto err_install_protocol_interface;
 	}
 
 					EFI_NATIVE_INTERFACE,
 					driver ) ) != 0 ) {
 		DBGC ( driver, "SNPDRV %p could not install driver binding: "
-		       "%x\n", driver, efirc );
+		       "%s\n", driver, efi_strerror ( efirc ) );
 		return EFIRC_TO_RC ( efirc );
 	}
 

src/interface/efi/efi_strerror.c

+/*
+ * Copyright (C) 2008 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdio.h>
+#include <gpxe/efi/efi.h>
+
+/** @file
+ *
+ * gPXE error message formatting for EFI
+ *
+ */
+
+/**
+ * Format EFI status code
+ *
+ * @v efirc		EFI status code
+ * @v efi_strerror	EFI status code string
+ */
+const char * efi_strerror ( EFI_STATUS efirc ) {
+	static char errbuf[32];
+
+	if ( ! efirc )
+		return "No error";
+
+	snprintf ( errbuf, sizeof ( errbuf ), "Error %lld",
+		   ( unsigned long long ) ( efirc ^ MAX_BIT ) );
+	return errbuf;
+}

src/interface/efi/efi_timer.c

 	EFI_STATUS efirc;
 
 	if ( ( efirc = bs->Stall ( usecs ) ) != 0 ) {
-		DBG ( "EFI could not delay for %ldus: %x\n",
-		      usecs, efirc );
+		DBG ( "EFI could not delay for %ldus: %s\n",
+		      usecs, efi_strerror ( efirc ) );
 		/* Probably screwed */
 	}
 }
 	/* Read CPU timer 0 (TSC) */
 	if ( ( efirc = cpu_arch->GetTimerValue ( cpu_arch, 0, &time,
 						 NULL ) ) != 0 ) {
-		DBG ( "EFI could not read CPU timer: %x\n", efirc );
+		DBG ( "EFI could not read CPU timer: %s\n",
+		      efi_strerror ( efirc ) );
 		/* Probably screwed */
 		return -1UL;
 	}

src/interface/efi/efi_umalloc.c

 						   EfiBootServicesData,
 						   new_pages,
 						   &phys_addr ) ) != 0 ) {
-			DBG ( "EFI could not allocate %d pages: %x\n",
-			      new_pages, efirc );
+			DBG ( "EFI could not allocate %d pages: %s\n",
+			      new_pages, efi_strerror ( efirc ) );
 			return UNULL;
 		}
 		assert ( phys_addr != 0 );
 		old_pages = ( EFI_SIZE_TO_PAGES ( old_size ) + 1 );
 		phys_addr = user_to_phys ( old_ptr, -EFI_PAGE_SIZE );
 		if ( ( efirc = bs->FreePages ( phys_addr, old_pages ) ) != 0 ){
-			DBG ( "EFI could not free %d pages at %llx: %x\n",
-			      old_pages, phys_addr, efirc );
+			DBG ( "EFI could not free %d pages at %llx: %s\n",
+			      old_pages, phys_addr, efi_strerror ( efirc ) );
 			/* Not fatal; we have leaked memory but successfully
 			 * allocated (if asked to do so).
 			 */