fallback.c: be more correct with device path code.

Rob Clark noticed while, implementing a UEFI like backend on u-boot,
that if a File Handle actually returns a meaningful device path from
DevicePathFromHandle(), we wind up with a horribly wrong device path in
the boot variable.  He's right, normal UEFI doesn't return that, which
means FileDevicePath() in our code currently does nothing at all.

Instead of all that, pass in the device's handle, and it'll do what
we're doing after the fact there.

Here's the log from a current run:

FS0:\> \efi\BOOT\BOOTX64.EFI
System BootOrder not found.  Initializing defaults.
find_boot_options:778:Found directory named "fedora"
try_boot_csv:532:Found file "\EFI\fedora\BOOT.CSV"
try_boot_csv:544:File looks like:
?shim.efi,Fedora,,This is the boot entry for Fedora

populate_stanza:495:CSV data: "shim.efi,Fedora,,This is the boot entry for Fedora"
populate_stanza:501:filename: "shim.efi"
populate_stanza:508:label: "Fedora"
populate_stanza:514:arguments: ""
add_to_boot_list:430:file DP: PciRoot(0)/Pci(0x1F,0x2)/Sata(0x0,0x0,0x0)/HD(Part1,Sig6584272A-D7B9-442A-B8A4-19B5EC4566F4)/\EFI\fedora\shim.efi
FindSubDevicePath:78:input device path: "PciRoot(0)/Pci(0x1F,0x2)/Sata(0x0,0x0,0x0)/HD(Part1,Sig6584272A-D7B9-442A-B8A4-19B5EC4566F4)/\EFI\fedora\shim.efi"
FindSubDevicePath:86:sub-path (4,1): "HD(Part1,Sig6584272A-D7B9-442A-B8A4-19B5EC4566F4)/\EFI\fedora\shim.efi"
add_to_boot_list:452:04 01 2A 00 01 00 00 00 00 08 00 00 00 00 00 00
add_to_boot_list:452:00 40 06 00 00 00 00 00 2A 27 84 65 B9 D7 2A 44
add_to_boot_list:452:B8 A4 19 B5 EC 45 66 F4 02 02 04 04 2E 00 5C 00
add_to_boot_list:452:45 00 46 00 49 00 5C 00 66 00 65 00 64 00 6F 00
add_to_boot_list:452:72 00 61 00 5C 00 73 00 68 00 69 00 6D 00 2E 00
add_to_boot_list:452:65 00 66 00 69 00 00 00 7F FF 04 00
add_to_boot_list:459:device path: "HD(Part1,Sig6584272A-D7B9-442A-B8A4-19B5EC4566F4)/\EFI\fedora\shim.efi"
Creating boot entry "Boot0000" with label "Fedora" for file "\EFI\fedora\shim.efi"
AddOption - Boot0000, then CurrentCount = 0x00000008
update_boot_order:390:nbootorder: 7
BootOrder: 0000 0002 0001 0003 0005 0006 0004

Signed-off-by: Peter Jones <pjones@redhat.com>

1 files changed, 5 insertions, 21 deletions

diff --git a/fallback.c b/fallback.c
index 2897d4ea..09749bb6 100644
--- a/fallback.c
+++ b/fallback.c
@@ -407,7 +407,7 @@ update_boot_order(void)
 }
 
 EFI_STATUS
-add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)
+add_to_boot_list(CHAR16 *dirname, CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)
 {
 	CHAR16 *fullpath = NULL;
 	UINT64 pathlen = 0;
@@ -417,25 +417,11 @@ add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *
 	if (EFI_ERROR(rc))
 		return rc;
 
-	EFI_DEVICE_PATH *dph = NULL;
-	EFI_DEVICE_PATH *file = NULL;
 	EFI_DEVICE_PATH *full_device_path = NULL;
 	EFI_DEVICE_PATH *dp = NULL;
 	CHAR16 *dps;
 
-	dph = DevicePathFromHandle(this_image->DeviceHandle);
-	if (!dph) {
-		rc = EFI_OUT_OF_RESOURCES;
-		goto err;
-	}
-
-	file = FileDevicePath(fh, fullpath);
-	if (!file) {
-		rc = EFI_OUT_OF_RESOURCES;
-		goto err;
-	}
-
-	full_device_path = AppendDevicePath(dph, file);
+	full_device_path = FileDevicePath(this_image->DeviceHandle, fullpath);
 	if (!full_device_path) {
 		rc = EFI_OUT_OF_RESOURCES;
 		goto err;
@@ -493,8 +479,6 @@ add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *
 	}
 
 err:
-	if (file)
-		FreePool(file);
 	if (full_device_path)
 		FreePool(full_device_path);
 	if (dp)
@@ -505,7 +489,7 @@ err:
 }
 
 EFI_STATUS
-populate_stanza(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *csv)
+populate_stanza(CHAR16 *dirname, CHAR16 *filename, CHAR16 *csv)
 {
 	CHAR16 *file = csv;
 	VerbosePrint(L"CSV data: \"%s\"\n", csv);
@@ -529,7 +513,7 @@ populate_stanza(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *c
 	/* This one is optional, so don't check if comma2 is 0 */
 	VerbosePrint(L"arguments: \"%s\"\n", arguments);
 
-	add_to_boot_list(fh, dirname, file, label, arguments);
+	add_to_boot_list(dirname, file, label, arguments);
 
 	return EFI_SUCCESS;
 }
@@ -583,7 +567,7 @@ try_boot_csv(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename)
 		CHAR16 c = start[l];
 		start[l] = L'\0';
 
-		populate_stanza(fh, dirname, filename, start);
+		populate_stanza(dirname, filename, start);
 
 		start[l] = c;
 		start += l;