Merge tag 'signed-efi-next' of git://github.com/agraf/u-boot

Patch queue for efi - 2018-01-28

This is the second part of patches for 2018.03-rc1, fixing
a few minor issues and adding a readme file for iSCSI booting.

9 files changed, 208 insertions, 27 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 0c7efde5a5b..0aecc18a6c6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -289,6 +289,7 @@ EFI PAYLOAD
 M:	Alexander Graf <agraf@suse.de>
 S:	Maintained
 T:	git git://github.com/agraf/u-boot.git
+F:	doc/README.iscsi
 F:	include/efi*
 F:	lib/efi*/
 F:	test/py/tests/test_efi*
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 51213c0293c..4233d36b722 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -126,8 +126,9 @@ static void *copy_fdt(void *fdt)
 
 static efi_status_t efi_do_enter(
 			efi_handle_t image_handle, struct efi_system_table *st,
-			asmlinkage ulong (*entry)(efi_handle_t image_handle,
-						  struct efi_system_table *st))
+			EFIAPI efi_status_t (*entry)(
+				efi_handle_t image_handle,
+				struct efi_system_table *st))
 {
 	efi_status_t ret = EFI_LOAD_ERROR;
 
@@ -138,7 +139,7 @@ static efi_status_t efi_do_enter(
 }
 
 #ifdef CONFIG_ARM64
-static efi_status_t efi_run_in_el2(asmlinkage ulong (*entry)(
+static efi_status_t efi_run_in_el2(EFIAPI efi_status_t (*entry)(
 			efi_handle_t image_handle, struct efi_system_table *st),
 			efi_handle_t image_handle, struct efi_system_table *st)
 {
@@ -162,8 +163,8 @@ static efi_status_t do_bootefi_exec(void *efi, void *fdt,
 	struct efi_device_path *memdp = NULL;
 	ulong ret;
 
-	ulong (*entry)(efi_handle_t image_handle, struct efi_system_table *st)
-		asmlinkage;
+	EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
+				     struct efi_system_table *st);
 	ulong fdt_pages, fdt_size, fdt_start, fdt_end;
 	const efi_guid_t fdt_guid = EFI_FDT_GUID;
 	bootm_headers_t img = { 0 };
@@ -372,6 +373,9 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		saddr = argv[1];
 
 		addr = simple_strtoul(saddr, NULL, 16);
+		/* Check that a numeric value was passed */
+		if (!addr && *saddr != '0')
+			return CMD_RET_USAGE;
 
 		if (argc > 2) {
 			sfdt = argv[2];
diff --git a/doc/README.iscsi b/doc/README.iscsi
new file mode 100644
index 00000000000..cb71c6e7446
--- /dev/null
+++ b/doc/README.iscsi
@@ -0,0 +1,159 @@
+# iSCSI booting with U-Boot and iPXE
+
+## Motivation
+
+U-Boot has only a reduced set of supported network protocols. The focus for
+network booting has been on UDP based protocols. A TCP stack and HTTP support
+are expected to be integrated in 2018 together with a wget command.
+
+For booting a diskless computer this leaves us with BOOTP or DHCP to get the
+address of a boot script. TFTP or NFS can be used to load the boot script, the
+operating system kernel and the initial file system (initrd).
+
+These protocols are insecure. The client cannot validate the authenticity
+of the contacted servers. And the server cannot verify the identity of the
+client.
+
+Furthermore the services providing the operating system loader or kernel are
+not the ones that the operating system typically will use. Especially in a SAN
+environment this makes updating the operating system a hassle. After installing
+a new kernel version the boot files have to be copied to the TFTP server
+directory.
+
+The HTTPS protocol provides certificate based validation of servers. Sensitive
+data like passwords can be securely transmitted.
+
+The iSCSI protocol is used for connecting storage attached networks. It
+provides mutual authentication using the CHAP protocol. It typically runs on
+a TCP transport.
+
+Thus a better solution than DHCP/TFTP/NFS boot would be to load a boot script
+via HTTPS and to download any other files needed for booting via iSCSI from the
+same target where the operating system is installed.
+
+An alternative to implementing these protocols in U-Boot is to use an existing
+software that can run on top of U-Boot. iPXE is the "swiss army knife" of
+network booting. It supports both HTTPS and iSCSI. It has a scripting engine for
+fine grained control of the boot process and can provide a command shell.
+
+iPXE can be built as an EFI application (named snp.efi) which can be loaded and
+run by U-Boot.
+
+## Boot sequence
+
+U-Boot loads the EFI application iPXE snp.efi using the bootefi command. This
+application has network access via the simple network protocol offered by
+U-Boot.
+
+iPXE executes its internal script. This script may optionally chain load a
+secondary boot script via HTTPS or open a shell.
+
+For the further boot process iPXE connects to the iSCSI server. This includes
+the mutual authentication using the CHAP protocol. After the authentication iPXE
+has access to the iSCSI targets.
+
+For a selected iSCSI target iPXE sets up a handle with the block IO protocol. It
+uses the ConnectController boot service of U-Boot to request U-Boot to connect a
+file system driver. U-Boot reads from the iSCSI drive via the block IO protocol
+offered by iPXE. It creates the partition handles and installs the simple file
+protocol. Now iPXE can call the simple file protocol to load Grub. U-Boot uses
+the block IO protocol offered by iPXE to fulfill the request.
+
+Once Grub is started it uses the same block IO protocol to load Linux. Via
+the EFI stub Linux is called as an EFI application.
+
+```
+               +--------+          +--------+
+               |        | Runs     |        |
+               | U-Boot |=========>| iPXE   |
+               | EFI    |          | snp.efi|
++--------+     |        | DHCP     |        |
+|        |<====|********|<=========|        |
+| DHCP   |     |        | Get IP   |        |
+| Server |     |        | Address  |        |
+|        |====>|********|=========>|        |
++--------+     |        | Response |        |
+               |        |          |        |
+               |        |          |        |
++--------+     |        | HTTPS    |        |
+|        |<====|********|<=========|        |
+| HTTPS  |     |        | Load     |        |
+| Server |     |        | Script   |        |
+|        |====>|********|=========>|        |
++--------+     |        |          |        |
+               |        |          |        |
+               |        |          |        |
++--------+     |        | iSCSI    |        |
+|        |<====|********|<=========|        |
+| iSCSI  |     |        | Auth     |        |
+| Server |====>|********|=========>|        |
+|        |     |        |          |        |
+|        |     |        | Loads    |        |
+|        |<====|********|<=========|        |        +--------+
+|        |     |        | Grub     |        | Runs   |        |
+|        |====>|********|=========>|        |=======>| Grub   |
+|        |     |        |          |        |        |        |
+|        |     |        |          |        |        |        |
+|        |     |        |          |        | Loads  |        |
+|        |<====|********|<=========|********|<=======|        |      +--------+
+|        |     |        |          |        | Linux  |        | Runs |        |
+|        |====>|********|=========>|********|=======>|        |=====>| Linux  |
+|        |     |        |          |        |        |        |      |        |
++--------+     +--------+          +--------+        +--------+      |        |
+                                                                     |        |
+                                                                     |        |
+                                                                     | ~ ~ ~ ~|
+```
+
+## Security
+
+The iSCSI protocol is not encrypted. The traffic could be secured using IPsec
+but neither U-Boot nor iPXE does support this. So we should at least separate
+the iSCSI traffic from all other network traffic. This can be achieved using a
+virtual local area network (VLAN).
+
+## Configuration
+
+### iPXE
+
+For running iPXE on arm64 the bin-arm64-efi/snp.efi build target is needed.
+
+    git clone http://git.ipxe.org/ipxe.git
+    cd ipxe/src
+    make bin-arm64-efi/snp.efi -j6 EMBED=myscript.ipxe
+
+The available commands for the boot script are documented at:
+
+http://ipxe.org/cmd
+
+Credentials are managed as environment variables. These are described here:
+
+http://ipxe.org/cfg
+
+iPXE by default will put the CPU to rest when waiting for input. U-Boot does
+not wake it up due to missing interrupt support. To avoid this behavior create
+file src/config/local/nap.h.
+
+    /* nap.h */
+    #undef NAP_EFIX86
+    #undef NAP_EFIARM
+    #define NAP_NULL
+
+The supported commands in iPXE are controlled by an include, too. Putting the
+following into src/config/local/general.h is sufficient for most use cases.
+
+    /* general.h */
+    #define NSLOOKUP_CMD            /* Name resolution command */
+    #define PING_CMD                /* Ping command */
+    #define NTP_CMD                 /* NTP commands */
+    #define VLAN_CMD                /* VLAN commands */
+    #define IMAGE_EFI               /* EFI image support */
+    #define DOWNLOAD_PROTO_HTTPS    /* Secure Hypertext Transfer Protocol */
+    #define DOWNLOAD_PROTO_FTP      /* File Transfer Protocol */
+    #define DOWNLOAD_PROTO_NFS      /* Network File System Protocol */
+    #define DOWNLOAD_PROTO_FILE     /* Local file system access */
+
+## Links
+
+* https://ipxe.org - iPXE open source boot firmware
+* https://www.gnu.org/software/grub/ - GNU Grub (Grand Unified Bootloader)
diff --git a/include/efi.h b/include/efi.h
index 2f0be9c86cb..98bddbac1ad 100644
--- a/include/efi.h
+++ b/include/efi.h
@@ -19,7 +19,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 
-#ifdef CONFIG_EFI_STUB_64BIT
+#if CONFIG_EFI_STUB_64BIT || (!defined(CONFIG_EFI_STUB) && defined(__x86_64__))
 /* EFI uses the Microsoft ABI which is not the default for GCC */
 #define EFIAPI __attribute__((ms_abi))
 #else
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index d2b6327119b..827c267b601 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -1,6 +1,10 @@
 config EFI_LOADER
 	bool "Support running EFI Applications in U-Boot"
 	depends on (ARM || X86) && OF_LIBFDT
+	# We need EFI_STUB_64BIT to be set on x86_64 with EFI_STUB
+	depends on !EFI_STUB || !X86_64 || EFI_STUB_64BIT
+	# We need EFI_STUB_32BIT to be set on x86_32 with EFI_STUB
+	depends on !EFI_STUB || !X86 || X86_64 || EFI_STUB_32BIT
 	default y
 	help
 	  Select this option if you want to run EFI applications (like grub2)
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 857d88a879e..c96b9d48c59 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -120,11 +120,9 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
 
 	if (lo.attributes & LOAD_OPTION_ACTIVE) {
 		efi_status_t ret;
-		u16 *str = NULL;
 
-		debug("%s: trying to load \"%ls\" from: %ls\n", __func__,
-		      lo.label, (str = efi_dp_str(lo.file_path)));
-		efi_free_pool(str);
+		debug("%s: trying to load \"%ls\" from %pD\n",
+		      __func__, lo.label, lo.file_path);
 
 		ret = efi_load_image_from_path(lo.file_path, &image);
 
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 39d8511fe38..da93498b36b 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -111,8 +111,11 @@ void efi_restore_gd(void)
 }
 
 /*
- * Two spaces per indent level, maxing out at 10.. which ought to be
- * enough for anyone ;-)
+ * Return a string for indenting with two spaces per level. A maximum of ten
+ * indent levels is supported. Higher indent levels will be truncated.
+ *
+ * @level	indent level
+ * @return	indent string
  */
 static const char *indent_string(int level)
 {
@@ -1364,16 +1367,18 @@ efi_status_t efi_setup_loaded_image(
 	obj->handle = info;
 
 	info->file_path = file_path;
-	if (device_path)
-		info->device_handle = efi_dp_find_obj(device_path, NULL);
 
-	/*
-	 * When asking for the device path interface, return
-	 * bootefi_device_path
-	 */
-	ret = efi_add_protocol(obj->handle, &efi_guid_device_path, device_path);
-	if (ret != EFI_SUCCESS)
-		goto failure;
+	if (device_path) {
+		info->device_handle = efi_dp_find_obj(device_path, NULL);
+		/*
+		 * When asking for the device path interface, return
+		 * bootefi_device_path
+		 */
+		ret = efi_add_protocol(obj->handle, &efi_guid_device_path,
+				       device_path);
+		if (ret != EFI_SUCCESS)
+			goto failure;
+	}
 
 	/*
 	 * When asking for the loaded_image interface, just
@@ -1456,7 +1461,7 @@ error:
  * for details.
  *
  * @boot_policy		true for request originating from the boot manager
- * @parent_image	the calles's image handle
+ * @parent_image	the caller's image handle
  * @file_path		the path of the image to load
  * @source_buffer	memory location from which the image is installed
  * @source_size		size of the memory area from which the image is
@@ -1534,8 +1539,8 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 					   unsigned long *exit_data_size,
 					   s16 **exit_data)
 {
-	asmlinkage ulong (*entry)(efi_handle_t image_handle,
-				  struct efi_system_table *st);
+	EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
+				     struct efi_system_table *st);
 	struct efi_loaded_image *info = image_handle;
 	efi_status_t ret;
 
@@ -1575,8 +1580,13 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
 
 	ret = EFI_CALL(entry(image_handle, &systab));
 
-	/* Should usually never get here */
-	return EFI_EXIT(ret);
+	/*
+	 * Usually UEFI applications call Exit() instead of returning.
+	 * But because the world doesn not consist of ponies and unicorns,
+	 * we're happy to emulate that behavior on behalf of a payload
+	 * that forgot.
+	 */
+	return EFI_CALL(systab.boottime->exit(image_handle, ret, 0, NULL));
 }
 
 /*
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 226f4eb3e51..5f7a5f17dc6 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -300,8 +300,9 @@ static char *device_path_string(char *buf, char *end, void *dp, int field_width,
 {
 	u16 *str;
 
+	/* If dp == NULL output the string '<NULL>' */
 	if (!dp)
-		return "<NULL>";
+		return string16(buf, end, dp, field_width, precision, flags);
 
 	str = efi_dp_str((struct efi_device_path *)dp);
 	if (!str)
diff --git a/test/print_ut.c b/test/print_ut.c
index 1aa68be7a9a..d8e9da8fa8f 100644
--- a/test/print_ut.c
+++ b/test/print_ut.c
@@ -44,6 +44,10 @@ static void efi_ut_print(void)
 
 	snprintf(str, sizeof(str), "_%pD_", buf);
 	assert(!strcmp("_/SD(3)_", str));
+
+	/* NULL device path */
+	snprintf(str, sizeof(str), "_%pD_", NULL);
+	assert(!strcmp("_<NULL>_", str));
 #endif
 }