[efi] Allow block devices to provide their own EFI device paths

Use the device path constructed via efi_describe() for the installed
EFI_BLOCK_IO_PROTOCOL device handle.

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

diff --git a/src/interface/efi/efi_block.c b/src/interface/efi/efi_block.c
index fa37be9d353ee1dae24c5cc453ebb7476f1353c1..c974ca065da464eb8f00b8294b34d6041bac25f9 100644 (file)
--- a/src/interface/efi/efi_block.c
+++ b/src/interface/efi/efi_block.c
@@ -64,23 +64,6 @@ EFI_REQUEST_PROTOCOL ( EFI_ACPI_TABLE_PROTOCOL, &acpi );
 /** Boot filename */
 static wchar_t efi_block_boot_filename[] = EFI_REMOVABLE_MEDIA_FILE_NAME;
 
-/** iPXE EFI block device vendor device path GUID */
-#define IPXE_BLOCK_DEVICE_PATH_GUID                                    \
-       { 0x8998b594, 0xf531, 0x4e87,                                   \
-         { 0x8b, 0xdf, 0x8f, 0x88, 0x54, 0x3e, 0x99, 0xd4 } }
-
-/** iPXE EFI block device vendor device path GUID */
-static EFI_GUID ipxe_block_device_path_guid
-       = IPXE_BLOCK_DEVICE_PATH_GUID;
-
-/** An iPXE EFI block device vendor device path */
-struct efi_block_vendor_path {
-       /** Generic vendor device path */
-       VENDOR_DEVICE_PATH vendor;
-       /** Block device URI */
-       CHAR16 uri[0];
-} __attribute__ (( packed ));
-
 /** EFI SAN device private data */
 struct efi_block_data {
        /** SAN device */
@@ -259,16 +242,8 @@ static void efi_block_connect ( struct san_device *sandev ) {
 static int efi_block_hook ( unsigned int drive, struct uri **uris,
                            unsigned int count, unsigned int flags ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-       EFI_DEVICE_PATH_PROTOCOL *end;
-       struct efi_block_vendor_path *vendor;
-       struct efi_snp_device *snpdev;
        struct san_device *sandev;
        struct efi_block_data *block;
-       size_t prefix_len;
-       size_t uri_len;
-       size_t vendor_len;
-       size_t len;
-       char *uri_buf;
        EFI_STATUS efirc;
        int rc;
 
@@ -279,24 +254,8 @@ static int efi_block_hook ( unsigned int drive, struct uri **uris,
                goto err_no_uris;
        }
 
-       /* Find an appropriate parent device handle */
-       snpdev = last_opened_snpdev();
-       if ( ! snpdev ) {
-               DBG ( "EFIBLK could not identify SNP device\n" );
-               rc = -ENODEV;
-               goto err_no_snpdev;
-       }
-
-       /* Calculate length of private data */
-       prefix_len = efi_path_len ( snpdev->path );
-       uri_len = format_uri ( uris[0], NULL, 0 );
-       vendor_len = ( sizeof ( *vendor ) +
-                      ( ( uri_len + 1 /* NUL */ ) * sizeof ( wchar_t ) ) );
-       len = ( sizeof ( *block ) + uri_len + 1 /* NUL */ + prefix_len +
-               vendor_len + sizeof ( *end ) );
-
        /* Allocate and initialise structure */
-       sandev = alloc_sandev ( uris, count, len );
+       sandev = alloc_sandev ( uris, count, sizeof ( *block ) );
        if ( ! sandev ) {
                rc = -ENOMEM;
                goto err_alloc;
@@ -311,26 +270,6 @@ static int efi_block_hook ( unsigned int drive, struct uri **uris,
        block->block_io.ReadBlocks = efi_block_io_read;
        block->block_io.WriteBlocks = efi_block_io_write;
        block->block_io.FlushBlocks = efi_block_io_flush;
-       uri_buf = ( ( ( void * ) block ) + sizeof ( *block ) );
-       block->path = ( ( ( void * ) uri_buf ) + uri_len + 1 /* NUL */ );
-
-       /* Construct device path */
-       memcpy ( block->path, snpdev->path, prefix_len );
-       vendor = ( ( ( void * ) block->path ) + prefix_len );
-       vendor->vendor.Header.Type = HARDWARE_DEVICE_PATH;
-       vendor->vendor.Header.SubType = HW_VENDOR_DP;
-       vendor->vendor.Header.Length[0] = ( vendor_len & 0xff );
-       vendor->vendor.Header.Length[1] = ( vendor_len >> 8 );
-       memcpy ( &vendor->vendor.Guid, &ipxe_block_device_path_guid,
-                sizeof ( vendor->vendor.Guid ) );
-       format_uri ( uris[0], uri_buf, ( uri_len + 1 /* NUL */ ) );
-       efi_snprintf ( vendor->uri, ( uri_len + 1 /* NUL */ ), "%s", uri_buf );
-       end = ( ( ( void * ) vendor ) + vendor_len );
-       end->Type = END_DEVICE_PATH_TYPE;
-       end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
-       end->Length[0] = sizeof ( *end );
-       DBGC ( sandev, "EFIBLK %#02x has device path %s\n",
-              drive, efi_devpath_text ( block->path ) );
 
        /* Register SAN device */
        if ( ( rc = register_sandev ( sandev, drive, flags ) ) != 0 ) {
@@ -345,6 +284,22 @@ static int efi_block_hook ( unsigned int drive, struct uri **uris,
        block->media.LastBlock =
                ( ( sandev->capacity.blocks >> sandev->blksize_shift ) - 1 );
 
+       /* Construct device path */
+       if ( ! sandev->active ) {
+               rc = -ENODEV;
+               DBGC ( sandev, "EFIBLK %#02x not active after registration\n",
+                      drive );
+               goto err_active;
+       }
+       block->path = efi_describe ( &sandev->active->block );
+       if ( ! block->path ) {
+               rc = -ENODEV;
+               DBGC ( sandev, "EFIBLK %#02x has no device path\n", drive );
+               goto err_describe;
+       }
+       DBGC ( sandev, "EFIBLK %#02x has device path %s\n",
+              drive, efi_devpath_text ( block->path ) );
+
        /* Install protocols */
        if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
                        &block->handle,
@@ -367,11 +322,14 @@ static int efi_block_hook ( unsigned int drive, struct uri **uris,
                        &efi_block_io_protocol_guid, &block->block_io,
                        &efi_device_path_protocol_guid, block->path, NULL );
  err_install:
+       free ( block->path );
+       block->path = NULL;
+ err_describe:
+ err_active:
        unregister_sandev ( sandev );
  err_register:
        sandev_put ( sandev );
  err_alloc:
- err_no_snpdev:
  err_no_uris:
        return rc;
 }
@@ -400,6 +358,10 @@ static void efi_block_unhook ( unsigned int drive ) {
                        &efi_block_io_protocol_guid, &block->block_io,
                        &efi_device_path_protocol_guid, block->path, NULL );
 
+       /* Free device path */
+       free ( block->path );
+       block->path = NULL;
+
        /* Unregister SAN device */
        unregister_sandev ( sandev );