src/interface/efi/efi_disklog.c - ipxe - Git at Google

 /*
  * Copyright (C) 2026 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_SECBOOT ( PERMITTED );

 #include <assert.h>
 #include <errno.h>
 #include <string.h>
 #include <ipxe/console.h>
 #include <ipxe/disklog.h>
 #include <ipxe/init.h>
 #include <ipxe/umalloc.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/Protocol/BlockIo.h>
 #include <ipxe/efi/Protocol/PartitionInfo.h>
 #include <config/console.h>

 /** @file
  *
  * EFI disk log console
  *
  */

 /* Set default console usage if applicable */
 #if ! ( defined ( CONSOLE_DISKLOG ) && CONSOLE_EXPLICIT ( CONSOLE_DISKLOG ) )
 #undef CONSOLE_DISKLOG
 #define CONSOLE_DISKLOG ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
 #endif

 /** EFI disk log console device handle */
 static EFI_HANDLE efi_disklog_handle;

 /** EFI disk log console block I/O protocol */
 static EFI_BLOCK_IO_PROTOCOL *efi_disklog_block;

 /** EFI disk log console media ID */
 static UINT32 efi_disklog_media_id;

 /** EFI disk log console */
 static struct disklog efi_disklog;

 struct console_driver efi_disklog_console __console_driver;

 /**
  * Write current logical block
  *
  * @ret rc		Return status code
  */
 static int efi_disklog_write ( void ) {
 	EFI_BLOCK_IO_PROTOCOL *block = efi_disklog_block;
 	struct disklog *disklog = &efi_disklog;
 	EFI_STATUS efirc;
 	int rc;

 	/* Write disk block */
 	if ( ( efirc = block->WriteBlocks ( block, efi_disklog_media_id,
 					    disklog->lba, disklog->blksize,
 					    disklog->buffer ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( disklog, "EFIDISKLOG %s could not write LBA %#llx: "
 		       "%s\n", efi_handle_name ( efi_disklog_handle ),
 		       ( ( unsigned long long ) disklog->lba ),
 		       strerror ( rc ) );
 		return rc;
 	}

 	return 0;
 }

 /** EFI disk log console operations */
 static struct disklog_operations efi_disklog_op = {
 	.write = efi_disklog_write,
 };

 /**
  * Write character to console
  *
  * @v character		Character
  */
 static void efi_disklog_putchar ( int character ) {

 	/* Write character */
 	disklog_putchar ( &efi_disklog, character );
 }

 /**
  * Open EFI disk log partition
  *
  * @v handle		Block device handle
  * @ret rc		Return status code
  */
 static int efi_disklog_open ( EFI_HANDLE handle ) {
 	struct disklog *disklog = &efi_disklog;
 	EFI_BLOCK_IO_PROTOCOL *block;
 	EFI_BLOCK_IO_MEDIA *media;
 	EFI_PARTITION_INFO_PROTOCOL *part;
 	void *buffer;
 	EFI_STATUS efirc;
 	int rc;

 	/* Record handle */
 	efi_disklog_handle = handle;

 	/* Open block I/O protocol for ephemeral usage */
 	if ( ( rc = efi_open ( handle, &efi_block_io_protocol_guid,
 			       &block ) ) != 0 ) {
 		DBGC ( disklog, "EFIDISKLOG %s could not open: %s\n",
 		       efi_handle_name ( handle ), strerror ( rc ) );
 		goto err_open;
 	}
 	media = block->Media;
 	efi_disklog_block = block;
 	efi_disklog_media_id = media->MediaId;

 	/* Check this is a partition */
 	if ( ! media->LogicalPartition ) {
 		DBGC2 ( disklog, "EFIDISKLOG %s is not a partition\n",
 			efi_handle_name ( handle ) );
 		rc = -ENOTTY;
 		goto err_not_partition;
 	}

 	/* Check partition type (if exposed by the platform) */
 	if ( ( rc = efi_open ( handle, &efi_partition_info_protocol_guid,
 			       &part ) ) == 0 ) {
 		if ( ( part->Type != PARTITION_TYPE_MBR ) ||
 		     ( part->Info.Mbr.OSIndicator != DISKLOG_PARTITION_TYPE )){
 			DBGC ( disklog, "EFIDISKLOG %s is not a log "
 			       "partition\n", efi_handle_name ( handle ) );
 			rc = -ENOTTY;
 			goto err_not_log;
 		}
 	} else {
 		DBGC2 ( disklog, "EFIDISKLOG %s has no partition info\n",
 			efi_handle_name ( handle ) );
 		/* Continue anyway */
 	}

 	/* Allocate buffer */
 	buffer = umalloc ( media->BlockSize );
 	if ( ! buffer ) {
 		rc = -ENOMEM;
 		goto err_alloc;
 	}

 	/* Read partition signature */
 	if ( ( efirc = block->ReadBlocks ( block, efi_disklog_media_id, 0,
 					   media->BlockSize, buffer ) ) != 0 ){
 		rc = -EEFI ( efirc );
 		DBGC ( disklog, "EFIDISKLOG %s could not read block 0: %s\n",
 		       efi_handle_name ( handle ), strerror ( rc ) );
 		goto err_read;
 	}

 	/* Initialise disk log console */
 	disklog_init ( disklog, &efi_disklog_op, &efi_disklog_console, buffer,
 		       media->BlockSize, 0, media->LastBlock );

 	/* Open disk log console */
 	if ( ( rc = disklog_open ( disklog ) ) != 0 ) {
 		DBGC ( disklog, "EFIDISKLOG %s could not initialise log: "
 		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
 		goto err_init;
 	}

 	/* Reopen handle for long-term use */
 	if ( ( rc = efi_open_by_driver ( handle, &efi_block_io_protocol_guid,
 					 &block ) ) != 0 ) {
 		DBGC ( disklog, "EFIDISKLOG %s could not reopen: %s\n",
 		       efi_handle_name ( handle ), strerror ( rc ) );
 		goto err_reopen;
 	}
 	if ( block != efi_disklog_block ) {
 		DBGC ( disklog, "EFIDISKLOG %s changed during reopening\n",
 		       efi_handle_name ( handle ) );
 		rc = -EPIPE;
 		goto err_reopen_mismatch;
 	}

 	DBGC ( disklog, "EFIDISKLOG using %s\n", efi_handle_name ( handle ) );
 	DBGC2 ( disklog, "EFIDISKLOG has %zd-byte LBA [%#x,%#llx]\n",
 		disklog->blksize, 0,
 		( ( unsigned long long ) disklog->max_lba ) );
 	return 0;

  err_reopen_mismatch:
 	efi_close_by_driver ( handle, &efi_block_io_protocol_guid );
  err_reopen:
  err_init:
  err_read:
 	ufree ( buffer );
  err_alloc:
  err_not_log:
  err_not_partition:
 	efi_disklog_block = NULL;
  err_open:
 	efi_disklog_handle = NULL;
 	return rc;
 }

 /**
  * Initialise EFI disk log console
  *
  */
 static void efi_disklog_init ( void ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_GUID *protocol = &efi_block_io_protocol_guid;
 	EFI_HANDLE *handles;
 	UINTN count;
 	unsigned int i;
 	EFI_STATUS efirc;
 	int rc;

 	/* Locate all block I/O protocol handles */
 	if ( ( efirc = bs->LocateHandleBuffer ( ByProtocol, protocol,
 						NULL, &count,
 						&handles ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( &efi_disklog, "EFIDISKLOG could not locate block I/O: "
 		       "%s\n", strerror ( rc ) );
 		goto err_locate;
 	}

 	/* Try each handle in turn */
 	for ( i = 0 ; i < count ; i++ ) {
 		if ( ( rc = efi_disklog_open ( handles[i] ) ) == 0 )
 			break;
 	}

 	bs->FreePool ( handles );
  err_locate:
 	return;
 }

 /**
  * EFI disk log console initialisation function
  */
 struct init_fn efi_disklog_init_fn __init_fn ( INIT_CONSOLE ) = {
 	.name = "disklog",
 	.initialise = efi_disklog_init,
 };

 /**
  * Shut down EFI disk log console
  *
  * @v booting		System is shutting down for OS boot
  */
 static void efi_disklog_shutdown ( int booting __unused ) {
 	struct disklog *disklog = &efi_disklog;

 	/* Do nothing if we have no EFI disk log console */
 	if ( ! efi_disklog_handle )
 		return;

 	/* Close EFI disk log console */
 	DBGC ( disklog, "EFIDISKLOG %s closed\n",
 	       efi_handle_name ( efi_disklog_handle ) );
 	efi_close_by_driver ( efi_disklog_handle,
 			      &efi_block_io_protocol_guid );
 	ufree ( disklog->buffer );
 	disklog->buffer = NULL;
 	efi_disklog_handle = NULL;
 	efi_disklog_block = NULL;
 }

 /** EFI disk log console shutdown function */
 struct startup_fn efi_disklog_startup_fn __startup_fn ( STARTUP_EARLY ) = {
 	.name = "disklog",
 	.shutdown = efi_disklog_shutdown,
 };

 /** EFI disk log console driver */
 struct console_driver efi_disklog_console __console_driver = {
 	.putchar = efi_disklog_putchar,
 	.disabled = CONSOLE_DISABLED,
 	.usage = CONSOLE_DISKLOG,
 };

 /* Request a log partition from genfsimg */
 IPXE_NOTE ( DISKLOG );
	/*
	* Copyright (C) 2026 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_SECBOOT ( PERMITTED );

	#include <assert.h>
	#include <errno.h>
	#include <string.h>
	#include <ipxe/console.h>
	#include <ipxe/disklog.h>
	#include <ipxe/init.h>
	#include <ipxe/umalloc.h>
	#include <ipxe/efi/efi.h>
	#include <ipxe/efi/Protocol/BlockIo.h>
	#include <ipxe/efi/Protocol/PartitionInfo.h>
	#include <config/console.h>

	/** @file
	*
	* EFI disk log console
	*
	*/

	/* Set default console usage if applicable */
	#if ! ( defined ( CONSOLE_DISKLOG ) && CONSOLE_EXPLICIT ( CONSOLE_DISKLOG ) )
	#undef CONSOLE_DISKLOG
	#define CONSOLE_DISKLOG ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
	#endif

	/** EFI disk log console device handle */
	static EFI_HANDLE efi_disklog_handle;

	/** EFI disk log console block I/O protocol */
	static EFI_BLOCK_IO_PROTOCOL *efi_disklog_block;

	/** EFI disk log console media ID */
	static UINT32 efi_disklog_media_id;

	/** EFI disk log console */
	static struct disklog efi_disklog;

	struct console_driver efi_disklog_console __console_driver;

	/**
	* Write current logical block
	*
	* @ret rc Return status code
	*/
	static int efi_disklog_write ( void ) {
	EFI_BLOCK_IO_PROTOCOL *block = efi_disklog_block;
	struct disklog *disklog = &efi_disklog;
	EFI_STATUS efirc;
	int rc;

	/* Write disk block */
	if ( ( efirc = block->WriteBlocks ( block, efi_disklog_media_id,
	disklog->lba, disklog->blksize,
	disklog->buffer ) ) != 0 ) {
	rc = -EEFI ( efirc );
	DBGC ( disklog, "EFIDISKLOG %s could not write LBA %#llx: "
	"%s\n", efi_handle_name ( efi_disklog_handle ),
	( ( unsigned long long ) disklog->lba ),
	strerror ( rc ) );
	return rc;
	}

	return 0;
	}

	/** EFI disk log console operations */
	static struct disklog_operations efi_disklog_op = {
	.write = efi_disklog_write,
	};

	/**
	* Write character to console
	*
	* @v character Character
	*/
	static void efi_disklog_putchar ( int character ) {

	/* Write character */
	disklog_putchar ( &efi_disklog, character );
	}

	/**
	* Open EFI disk log partition
	*
	* @v handle Block device handle
	* @ret rc Return status code
	*/
	static int efi_disklog_open ( EFI_HANDLE handle ) {
	struct disklog *disklog = &efi_disklog;
	EFI_BLOCK_IO_PROTOCOL *block;
	EFI_BLOCK_IO_MEDIA *media;
	EFI_PARTITION_INFO_PROTOCOL *part;
	void *buffer;
	EFI_STATUS efirc;
	int rc;

	/* Record handle */
	efi_disklog_handle = handle;

	/* Open block I/O protocol for ephemeral usage */
	if ( ( rc = efi_open ( handle, &efi_block_io_protocol_guid,
	&block ) ) != 0 ) {
	DBGC ( disklog, "EFIDISKLOG %s could not open: %s\n",
	efi_handle_name ( handle ), strerror ( rc ) );
	goto err_open;
	}
	media = block->Media;
	efi_disklog_block = block;
	efi_disklog_media_id = media->MediaId;

	/* Check this is a partition */
	if ( ! media->LogicalPartition ) {
	DBGC2 ( disklog, "EFIDISKLOG %s is not a partition\n",
	efi_handle_name ( handle ) );
	rc = -ENOTTY;
	goto err_not_partition;
	}

	/* Check partition type (if exposed by the platform) */
	if ( ( rc = efi_open ( handle, &efi_partition_info_protocol_guid,
	&part ) ) == 0 ) {
	if ( ( part->Type != PARTITION_TYPE_MBR ) \|\|
	( part->Info.Mbr.OSIndicator != DISKLOG_PARTITION_TYPE )){
	DBGC ( disklog, "EFIDISKLOG %s is not a log "
	"partition\n", efi_handle_name ( handle ) );
	rc = -ENOTTY;
	goto err_not_log;
	}
	} else {
	DBGC2 ( disklog, "EFIDISKLOG %s has no partition info\n",
	efi_handle_name ( handle ) );
	/* Continue anyway */
	}

	/* Allocate buffer */
	buffer = umalloc ( media->BlockSize );
	if ( ! buffer ) {
	rc = -ENOMEM;
	goto err_alloc;
	}

	/* Read partition signature */
	if ( ( efirc = block->ReadBlocks ( block, efi_disklog_media_id, 0,
	media->BlockSize, buffer ) ) != 0 ){
	rc = -EEFI ( efirc );
	DBGC ( disklog, "EFIDISKLOG %s could not read block 0: %s\n",
	efi_handle_name ( handle ), strerror ( rc ) );
	goto err_read;
	}

	/* Initialise disk log console */
	disklog_init ( disklog, &efi_disklog_op, &efi_disklog_console, buffer,
	media->BlockSize, 0, media->LastBlock );

	/* Open disk log console */
	if ( ( rc = disklog_open ( disklog ) ) != 0 ) {
	DBGC ( disklog, "EFIDISKLOG %s could not initialise log: "
	"%s\n", efi_handle_name ( handle ), strerror ( rc ) );
	goto err_init;
	}

	/* Reopen handle for long-term use */
	if ( ( rc = efi_open_by_driver ( handle, &efi_block_io_protocol_guid,
	&block ) ) != 0 ) {
	DBGC ( disklog, "EFIDISKLOG %s could not reopen: %s\n",
	efi_handle_name ( handle ), strerror ( rc ) );
	goto err_reopen;
	}
	if ( block != efi_disklog_block ) {
	DBGC ( disklog, "EFIDISKLOG %s changed during reopening\n",
	efi_handle_name ( handle ) );
	rc = -EPIPE;
	goto err_reopen_mismatch;
	}

	DBGC ( disklog, "EFIDISKLOG using %s\n", efi_handle_name ( handle ) );
	DBGC2 ( disklog, "EFIDISKLOG has %zd-byte LBA [%#x,%#llx]\n",
	disklog->blksize, 0,
	( ( unsigned long long ) disklog->max_lba ) );
	return 0;

	err_reopen_mismatch:
	efi_close_by_driver ( handle, &efi_block_io_protocol_guid );
	err_reopen:
	err_init:
	err_read:
	ufree ( buffer );
	err_alloc:
	err_not_log:
	err_not_partition:
	efi_disklog_block = NULL;
	err_open:
	efi_disklog_handle = NULL;
	return rc;
	}

	/**
	* Initialise EFI disk log console
	*
	*/
	static void efi_disklog_init ( void ) {
	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
	EFI_GUID *protocol = &efi_block_io_protocol_guid;
	EFI_HANDLE *handles;
	UINTN count;
	unsigned int i;
	EFI_STATUS efirc;
	int rc;

	/* Locate all block I/O protocol handles */
	if ( ( efirc = bs->LocateHandleBuffer ( ByProtocol, protocol,
	NULL, &count,
	&handles ) ) != 0 ) {
	rc = -EEFI ( efirc );
	DBGC ( &efi_disklog, "EFIDISKLOG could not locate block I/O: "
	"%s\n", strerror ( rc ) );
	goto err_locate;
	}

	/* Try each handle in turn */
	for ( i = 0 ; i < count ; i++ ) {
	if ( ( rc = efi_disklog_open ( handles[i] ) ) == 0 )
	break;
	}

	bs->FreePool ( handles );
	err_locate:
	return;
	}

	/**
	* EFI disk log console initialisation function
	*/
	struct init_fn efi_disklog_init_fn __init_fn ( INIT_CONSOLE ) = {
	.name = "disklog",
	.initialise = efi_disklog_init,
	};

	/**
	* Shut down EFI disk log console
	*
	* @v booting System is shutting down for OS boot
	*/
	static void efi_disklog_shutdown ( int booting __unused ) {
	struct disklog *disklog = &efi_disklog;

	/* Do nothing if we have no EFI disk log console */
	if ( ! efi_disklog_handle )
	return;

	/* Close EFI disk log console */
	DBGC ( disklog, "EFIDISKLOG %s closed\n",
	efi_handle_name ( efi_disklog_handle ) );
	efi_close_by_driver ( efi_disklog_handle,
	&efi_block_io_protocol_guid );
	ufree ( disklog->buffer );
	disklog->buffer = NULL;
	efi_disklog_handle = NULL;
	efi_disklog_block = NULL;
	}

	/** EFI disk log console shutdown function */
	struct startup_fn efi_disklog_startup_fn __startup_fn ( STARTUP_EARLY ) = {
	.name = "disklog",
	.shutdown = efi_disklog_shutdown,
	};

	/** EFI disk log console driver */
	struct console_driver efi_disklog_console __console_driver = {
	.putchar = efi_disklog_putchar,
	.disabled = CONSOLE_DISABLED,
	.usage = CONSOLE_DISKLOG,
	};

	/* Request a log partition from genfsimg */
	IPXE_NOTE ( DISKLOG );