[efi] Split out autoexec script portions of efi_autoboot.c

The "autoboot device" and "autoexec script" functionalities in
efi_autoboot.c are unrelated except in that they both need to be
invoked by efiprefix.c before device drivers are loaded.

Split out the autoexec script portions to a separate file to avoid
potential confusion.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/src/interface/efi/efi_autoexec.c b/src/interface/efi/efi_autoexec.c
new file mode 100644
index 00000000..88eb379b
--- /dev/null
+++ b/src/interface/efi/efi_autoexec.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2021 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 <string.h>
+#include <errno.h>
+#include <ipxe/image.h>
+#include <ipxe/init.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_autoexec.h>
+#include <ipxe/efi/Protocol/SimpleFileSystem.h>
+#include <ipxe/efi/Guid/FileInfo.h>
+
+/** @file
+ *
+ * EFI autoexec script
+ *
+ */
+
+/** Autoexec script filename */
+#define AUTOEXEC_FILENAME L"autoexec.ipxe"
+
+/** Autoexec script image name */
+#define AUTOEXEC_NAME "autoexec.ipxe"
+
+/** Autoexec script (if any) */
+static void *efi_autoexec;
+
+/** Autoexec script length */
+static size_t efi_autoexec_len;
+
+/**
+ * Load autoexec script
+ *
+ * @v device		Device handle
+ * @ret rc		Return status code
+ */
+int efi_autoexec_load ( 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] ) ];
+	} info;
+	EFI_FILE_PROTOCOL *root;
+	EFI_FILE_PROTOCOL *file;
+	UINTN size;
+	VOID *data;
+	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,
+					  &u.interface, efi_image_handle,
+					  device,
+					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s has no filesystem instance: %s\n",
+		       efi_handle_name ( device ), strerror ( rc ) );
+		goto err_filesystem;
+	}
+
+	/* Open root directory */
+	if ( ( efirc = u.fs->OpenVolume ( u.fs, &root ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not open volume: %s\n",
+		       efi_handle_name ( device ), strerror ( rc ) );
+		goto err_volume;
+	}
+
+	/* Open autoexec script */
+	if ( ( efirc = root->Open ( root, &file, name,
+				    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 ) );
+		goto err_open;
+	}
+
+	/* Get file information */
+	size = sizeof ( info );
+	if ( ( efirc = file->GetInfo ( file, &efi_file_info_id, &size,
+				       &info ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not get %ls info: %s\n",
+		       efi_handle_name ( device ), name, strerror ( rc ) );
+		goto err_getinfo;
+	}
+	size = info.info.FileSize;
+
+	/* Ignore zero-length files */
+	if ( ! size ) {
+		rc = -EINVAL;
+		DBGC ( device, "EFI %s has zero-length %ls\n",
+		       efi_handle_name ( device ), name );
+		goto err_empty;
+	}
+
+	/* Allocate temporary copy */
+	if ( ( efirc = bs->AllocatePool ( EfiBootServicesData, size,
+					  &data ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( device, "EFI %s could not allocate %ls: %s\n",
+		       efi_handle_name ( device ), name, strerror ( rc ) );
+		goto err_alloc;
+	}
+
+	/* Read file */
+	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 ) );
+		goto err_read;
+	}
+
+	/* Record autoexec script */
+	efi_autoexec = data;
+	efi_autoexec_len = size;
+	data = NULL;
+	DBGC ( device, "EFI %s found %ls\n",
+	       efi_handle_name ( device ), name );
+
+	/* Success */
+	rc = 0;
+
+ err_read:
+	if ( data )
+		bs->FreePool ( data );
+ err_alloc:
+ err_empty:
+ err_getinfo:
+	file->Close ( file );
+ err_open:
+	root->Close ( root );
+ err_volume:
+	bs->CloseProtocol ( device, &efi_simple_file_system_protocol_guid,
+			    efi_image_handle, device );
+ err_filesystem:
+	return rc;
+}
+
+/**
+ * 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 */
+	if ( ! efi_autoexec )
+		return;
+
+	/* Create autoexec image */
+	image = image_memory ( 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 );
+		return;
+	}
+	DBGC ( device, "EFI %s registered %s\n",
+	       efi_handle_name ( device ), name );
+
+	/* Free temporary copy */
+	bs->FreePool ( efi_autoexec );
+	efi_autoexec = NULL;
+}
+
+/** Autoexec script startup function */
+struct startup_fn efi_autoexec_startup_fn __startup_fn ( STARTUP_NORMAL ) = {
+	.name = "efi_autoexec",
+	.startup = efi_autoexec_startup,
+};