efi_loader: flesh out device-path to text

It needs to handle more device-path node types, and also multiple levels
of path hierarchy.  To simplify this, initially construct utf8 string to
a temporary buffer, and then allocate the real utf16 buffer that is
returned.  This should be mostly for debugging or at least not critical-
path so an extra copy won't hurt, and is saner than the alternative.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/efi_api.h

@@ -304,6 +304,7 @@ struct efi_device_path_vendor {
 
 #define EFI_PNP_ID(ID)				(u32)(((ID) << 16) | 0x41D0)
 #define EISA_PNP_ID(ID)				EFI_PNP_ID(ID)
+#define EISA_PNP_NUM(ID)			((ID) >> 16)
 
 struct efi_device_path_acpi_path {
 	struct efi_device_path dp;

include/efi_loader.h

@@ -80,6 +80,8 @@ extern struct efi_simple_input_interface efi_con_in;
 extern const struct efi_console_control_protocol efi_console_control;
 extern const struct efi_device_path_to_text_protocol efi_device_path_to_text;
 
+uint16_t *efi_dp_str(struct efi_device_path *dp);
+
 extern const efi_guid_t efi_guid_console_control;
 extern const efi_guid_t efi_guid_device_path;
 extern const efi_guid_t efi_guid_loaded_image;

lib/efi_loader/efi_device_path_to_text.c

@@ -15,82 +15,197 @@
 const efi_guid_t efi_guid_device_path_to_text_protocol =
 		EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
 
+static char *dp_unknown(char *s, struct efi_device_path *dp)
+{
+	s += sprintf(s, "/UNKNOWN(%04x,%04x)", dp->type, dp->sub_type);
+	return s;
+}
+
+static char *dp_hardware(char *s, struct efi_device_path *dp)
+{
+	switch (dp->sub_type) {
+	case DEVICE_PATH_SUB_TYPE_VENDOR: {
+		struct efi_device_path_vendor *vdp =
+			(struct efi_device_path_vendor *)dp;
+		s += sprintf(s, "/VenHw(%pUl)", &vdp->guid);
+		break;
+	}
+	default:
+		s = dp_unknown(s, dp);
+		break;
+	}
+	return s;
+}
+
+static char *dp_acpi(char *s, struct efi_device_path *dp)
+{
+	switch (dp->sub_type) {
+	case DEVICE_PATH_SUB_TYPE_ACPI_DEVICE: {
+		struct efi_device_path_acpi_path *adp =
+			(struct efi_device_path_acpi_path *)dp;
+		s += sprintf(s, "/Acpi(PNP%04x", EISA_PNP_NUM(adp->hid));
+		if (adp->uid)
+			s += sprintf(s, ",%d", adp->uid);
+		s += sprintf(s, ")");
+		break;
+	}
+	default:
+		s = dp_unknown(s, dp);
+		break;
+	}
+	return s;
+}
+
+static char *dp_msging(char *s, struct efi_device_path *dp)
+{
+	switch (dp->sub_type) {
+	case DEVICE_PATH_SUB_TYPE_MSG_USB: {
+		struct efi_device_path_usb *udp =
+			(struct efi_device_path_usb *)dp;
+		s += sprintf(s, "/Usb(0x%x,0x%x)", udp->parent_port_number,
+			     udp->usb_interface);
+		break;
+	}
+	case DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR: {
+		struct efi_device_path_mac_addr *mdp =
+			(struct efi_device_path_mac_addr *)dp;
+
+		if (mdp->if_type != 0 && mdp->if_type != 1)
+			break;
+
+		s += sprintf(s, "/MAC(%02x%02x%02x%02x%02x%02x,0x%1x)",
+			mdp->mac.addr[0], mdp->mac.addr[1],
+			mdp->mac.addr[2], mdp->mac.addr[3],
+			mdp->mac.addr[4], mdp->mac.addr[5],
+			mdp->if_type);
+
+		break;
+	}
+	case DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS: {
+		struct efi_device_path_usb_class *ucdp =
+			(struct efi_device_path_usb_class *)dp;
+
+		s += sprintf(s, "/USBClass(%x,%x,%x,%x,%x)",
+			ucdp->vendor_id, ucdp->product_id,
+			ucdp->device_class, ucdp->device_subclass,
+			ucdp->device_protocol);
+
+		break;
+	}
+	case DEVICE_PATH_SUB_TYPE_MSG_SD:
+	case DEVICE_PATH_SUB_TYPE_MSG_MMC: {
+		const char *typename =
+			(dp->sub_type == DEVICE_PATH_SUB_TYPE_MSG_SD) ?
+					"SDCard" : "MMC";
+		struct efi_device_path_sd_mmc_path *sddp =
+			(struct efi_device_path_sd_mmc_path *)dp;
+		s += sprintf(s, "/%s(Slot%u)", typename, sddp->slot_number);
+		break;
+	}
+	default:
+		s = dp_unknown(s, dp);
+		break;
+	}
+	return s;
+}
+
+static char *dp_media(char *s, struct efi_device_path *dp)
+{
+	switch (dp->sub_type) {
+	case DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH: {
+		struct efi_device_path_hard_drive_path *hddp =
+			(struct efi_device_path_hard_drive_path *)dp;
+		void *sig = hddp->partition_signature;
+
+		switch (hddp->signature_type) {
+		case SIG_TYPE_MBR:
+			s += sprintf(s, "/HD(Part%d,Sig%08x)",
+				     hddp->partition_number,
+				     *(uint32_t *)sig);
+			break;
+		case SIG_TYPE_GUID:
+			s += sprintf(s, "/HD(Part%d,Sig%pUl)",
+				     hddp->partition_number, sig);
+		default:
+			s += sprintf(s, "/HD(Part%d,MBRType=%02x,SigType=%02x)",
+				     hddp->partition_number, hddp->partmap_type,
+				     hddp->signature_type);
+		}
+
+		break;
+	}
+	case DEVICE_PATH_SUB_TYPE_CDROM_PATH: {
+		struct efi_device_path_cdrom_path *cddp =
+			(struct efi_device_path_cdrom_path *)dp;
+		s += sprintf(s, "/CDROM(0x%x)", cddp->boot_entry);
+		break;
+	}
+	case DEVICE_PATH_SUB_TYPE_FILE_PATH: {
+		struct efi_device_path_file_path *fp =
+			(struct efi_device_path_file_path *)dp;
+		int slen = (dp->length - sizeof(*dp)) / 2;
+		s += sprintf(s, "/%-*ls", slen, fp->str);
+		break;
+	}
+	default:
+		s = dp_unknown(s, dp);
+		break;
+	}
+	return s;
+}
+
 static uint16_t *efi_convert_device_node_to_text(
-		struct efi_device_path *device_node,
+		struct efi_device_path *dp,
 		bool display_only,
 		bool allow_shortcuts)
 {
-	unsigned long buffer_size;
+	unsigned long len;
 	efi_status_t r;
-	uint16_t *buffer = NULL;
+	char buf[512];  /* this ought be be big enough for worst case */
-	int i;
+	char *str = buf;
+	uint16_t *out;
 
-	switch (device_node->type) {
+	while (dp) {
-	case DEVICE_PATH_TYPE_END:
+		switch (dp->type) {
+		case DEVICE_PATH_TYPE_HARDWARE_DEVICE:
+			str = dp_hardware(str, dp);
+			break;
+		case DEVICE_PATH_TYPE_ACPI_DEVICE:
+			str = dp_acpi(str, dp);
+			break;
+		case DEVICE_PATH_TYPE_MESSAGING_DEVICE:
+			str = dp_msging(str, dp);
+			break;
+		case DEVICE_PATH_TYPE_MEDIA_DEVICE:
+			str = dp_media(str, dp);
+			break;
+		default:
+			str = dp_unknown(str, dp);
+		}
+
+		dp = efi_dp_next(dp);
+	}
+
+	*str++ = '\0';
+
+	len = str - buf;
+	r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, 2 * len, (void **)&out);
+	if (r != EFI_SUCCESS)
 		return NULL;
-	case DEVICE_PATH_TYPE_MESSAGING_DEVICE:
-		switch (device_node->sub_type) {
-		case DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR: {
-			struct efi_device_path_mac_addr *dp =
-				(struct efi_device_path_mac_addr *)device_node;
 
-			if (dp->if_type != 0 && dp->if_type != 1)
+	ascii2unicode(out, buf);
-				break;
+	out[len - 1] = 0;
-			r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES,
-					      2 * MAC_OUTPUT_LEN,
-					      (void **)&buffer);
-			if (r != EFI_SUCCESS)
-				return NULL;
-			sprintf((char *)buffer,
-				"MAC(%02x%02x%02x%02x%02x%02x,0x%1x)",
-				dp->mac.addr[0], dp->mac.addr[1],
-				dp->mac.addr[2], dp->mac.addr[3],
-				dp->mac.addr[4], dp->mac.addr[5],
-				dp->if_type);
-			for (i = MAC_OUTPUT_LEN - 1; i >= 0; --i)
-				buffer[i] = ((uint8_t *)buffer)[i];
-			break;
-			}
-		}
-		break;
-	case DEVICE_PATH_TYPE_MEDIA_DEVICE:
-		switch (device_node->sub_type) {
-		case DEVICE_PATH_SUB_TYPE_FILE_PATH: {
-			struct efi_device_path_file_path *fp =
-				(struct efi_device_path_file_path *)device_node;
-			buffer_size = device_node->length - 4;
-			r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES,
-					      buffer_size, (void **) &buffer);
-			if (r != EFI_SUCCESS)
-				return NULL;
-			memcpy(buffer, fp->str, buffer_size);
-			break;
-		}
-		}
-		break;
-	}
 
-	/*
+	return out;
-	 * For all node types that we do not yet support return
-	 * 'UNKNOWN(type,subtype)'.
-	 */
-	if (!buffer) {
-		r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES,
-				      2 * UNKNOWN_OUTPUT_LEN,
-				      (void **)&buffer);
-		if (r != EFI_SUCCESS)
-			return NULL;
-		sprintf((char *)buffer,
-			"UNKNOWN(%04x,%04x)",
-			device_node->type,
-			device_node->sub_type);
-		for (i = UNKNOWN_OUTPUT_LEN - 1; i >= 0; --i)
-			buffer[i] = ((uint8_t *)buffer)[i];
-	}
-
-	return buffer;
 }
 
+/* helper for debug prints.. efi_free_pool() the result. */
+uint16_t *efi_dp_str(struct efi_device_path *dp)
+{
+	return efi_convert_device_node_to_text(dp, true, true);
+}
+
+
 static uint16_t EFIAPI *efi_convert_device_node_to_text_ext(
 		struct efi_device_path *device_node,
 		bool display_only,