Re: [U-Boot] [PATCH V2 4/4] cmd_part: add partition-related command

On 09/05/2012 05:03 PM, Stephen Warren wrote:

From: Stephen Warren swarren@nvidia.com

This implements the following:

part uuid mmc 0:1 -> print partition UUID part uuid mmc 0:1 uuid -> set environment variable to partition UUID

What's the reason to not always both print out and set the uuid env var?

Perhaps the env name should be partuuid or part_uuid as you could have uuid's for other purposes?

This can be useful when writing a bootcmd which searches all known devices for something bootable, and then wants the kernel to use the same partition as the root device, e.g.:

part uuid ${devtype} ${devnum}:${rootpart} uuid setenv bootargs root=PARTUUID=${uuid} ...

It is expected that further part sub-commands will be added later, e.g. to find which partition on a disk is marked bootable, to write new partition tables to disk, etc.

A list command would be useful and would be better located here than under scsi or other interface commands. Perhaps instead of printing a single part uuid, you should make a list command that prints all partitions and their UUIDs. That would address my first question.

Rob

Signed-off-by: Stephen Warren swarren@nvidia.com

v2: validate that CONFIG_PARTITION_UUID is defined when CONFIG_CMD_PART is

Note: If Rob Herring's proposed patch "disk/part: introduce get_device_and_partition" is applied, the body of do_partuuid() should be reworked to use Rob's new function get_device_and_partition().

---

common/Makefile | 1 + common/cmd_part.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 105 insertions(+), 0 deletions(-) create mode 100644 common/cmd_part.c

diff --git a/common/Makefile b/common/Makefile index 3d62775..449b390 100644 --- a/common/Makefile +++ b/common/Makefile @@ -129,6 +129,7 @@ COBJS-$(CONFIG_CMD_NAND) += cmd_nand.o COBJS-$(CONFIG_CMD_NET) += cmd_net.o COBJS-$(CONFIG_CMD_ONENAND) += cmd_onenand.o COBJS-$(CONFIG_CMD_OTP) += cmd_otp.o +COBJS-$(CONFIG_CMD_PART) += cmd_part.o ifdef CONFIG_PCI COBJS-$(CONFIG_CMD_PCI) += cmd_pci.o endif diff --git a/common/cmd_part.c b/common/cmd_part.c new file mode 100644 index 0000000..1b15ae9 --- /dev/null +++ b/common/cmd_part.c @@ -0,0 +1,104 @@ +/*

• • Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
• • made from cmd_ext2, which was:
• • (C) Copyright 2004
• • esd gmbh <www.esd-electronics.com>
• • Reinhard Arlt reinhard.arlt@esd-electronics.com
• • made from cmd_reiserfs by
• • (C) Copyright 2003 - 2004
• • Sysgo Real-Time Solutions, AG <www.elinos.com>
• • Pavel Bartusek pba@sysgo.com
• • See file CREDITS for list of people who contributed to this
• • project.
• • 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 (at your option) 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, see http://www.gnu.org/licenses/.
• */

+#include <common.h> +#include <config.h> +#include <command.h> +#include <part.h> +#include <vsprintf.h>

+#ifndef CONFIG_PARTITION_UUIDS +#error CONFIG_PARTITION_UUIDS must be enabled for CONFIG_CMD_PART to be enabled +#endif

+int do_partuuid(int argc, char * const argv[]) +{

• int dev;
• int part;
• char *ep;
• block_dev_desc_t *dev_desc;
• disk_partition_t info;
• if (argc < 2)

• return CMD_RET_USAGE;
  

• if (argc > 3)

• return CMD_RET_USAGE;
  

• dev = (int)simple_strtoul(argv[1], &ep, 16);
• dev_desc = get_dev(argv[0], dev);
• if (dev_desc == NULL) {

• printf("Block device %s %d not supported\n", argv[0], dev);
  

• return 1;
  

• }
• if (*ep) {

• if (*ep != ':') {
  

• 	puts("Invalid device; use dev[:part]\n");
  

• 	return 1;
  

• }
  

• part = (int)simple_strtoul(++ep, NULL, 16);
  

• } else {

• part = 1;
  

• }
• if (get_partition_info(dev_desc, part, &info)) {

• printf("Bad partition %d\n", part);
  

• return 1;
  

• }
• if (argc > 2)

• setenv(argv[2], info.uuid);
  

• else

• printf("%s\n", info.uuid);
  

• return 0;

+}

+int do_part(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{

• if (argc < 2)

• return CMD_RET_USAGE;
  

• if (!strcmp(argv[1], "uuid"))

• return do_partuuid(argc - 2, argv + 2);
  

• return CMD_RET_USAGE;

+}

+U_BOOT_CMD(

• part, 5, 1, do_part,
• "disk partition related commands",
• "part uuid <interface> <dev[:part]>\n"
• " - print partition UUID\n"
• "part uuid <interface> <dev[:part]> <varname>\n"
• " - set environment variable to partition UUID"

+);