gpt: add part-uuid and part-num subcommands
PATCH 1/1 gpt: add part-uuid and part-num subcommands
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
--- cmd/gpt.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ doc/README.gpt | 21 ++++++++++++++++++ 2 files changed, 88 insertions(+)
cmd/gpt.c +67 -0
@@ -355,6 +355,64 @@ static int do_get_gpt_info(struct blk_desc *dev_desc) }return ret; } + +static struct disk_part *find_part_by_label (const char *label) +{ +struct disk_part *part =NULL ; +struct disk_part *curr; + +list_for_each_entry (curr, &disk_partitions, list) { +/* Check for the first match of the label we're looking +* for against the partition label */ +if (!strcmp ((const char *)curr->gpt_part_info.name, + label)) { + part = curr; +break ; + } + } + +return part; +} + +/* Find a partition UUID by label and save that UUID to the environment +* variable specified */ +static int do_get_part_uuid (struct blk_desc *dev_desc,const char *label, +const char *namestr) +{ +int ret; + + ret =get_gpt_info (dev_desc); +if (ret >0 ) { +struct disk_part *part =find_part_by_label (label); +if (part) { +env_set (namestr, part->gpt_part_info.uuid); + ret =0 ; + } + +del_gpt_info (); + } + +return ret; +} + +/* Find a partition number by label and save that number to the environment +* variable specified */ +static int do_get_part_num (struct blk_desc *dev_desc,const char *label, +const char *namestr) +{ +int ret =get_gpt_info (dev_desc); +if (ret >0 ) { +struct disk_part *part =find_part_by_label (label); +if (part) { +env_set_ulong (namestr, part->partnum); + ret =0 ; + } + +del_gpt_info (); + } + +return ret; +}#endif /**
@@ -851,6 +909,10 @@ static int do_gpt(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) #ifdef CONFIG_CMD_GPT_RENAME }else if (strcmp (argv[1 ],"read" ) ==0 ) { ret =do_get_gpt_info (blk_dev_desc); + }else if (strcmp (argv[1 ],"part-uuid" ) ==0 && argc ==6 ) { + ret =do_get_part_uuid (blk_dev_desc, argv[4 ], argv[5 ]); + }else if (strcmp (argv[1 ],"part-num" ) ==0 && argc ==6 ) { + ret =do_get_part_num (blk_dev_desc, argv[4 ], argv[5 ]); }else if ((strcmp (argv[1 ],"swap" ) ==0 ) || (strcmp (argv[1 ],"rename" ) ==0 )) { ret =do_rename_gpt_parts (blk_dev_desc, argv[1 ], argv[4 ], argv[5 ]);
@@ -887,6 +949,11 @@ U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt," gpt guid mmc 0\n" " gpt guid mmc 0 varname\n" #ifdef CONFIG_CMD_GPT_RENAME +"gpt partition label commands:\n" +"gpt part-uuid <interface> <dev> <label> <varname>\n" +" - set environment variable to UUID of label\n" +"gpt part-num <interface> <dev> <label> <varname>\n" +" - set environment variable to partition number of label\n" "gpt partition renaming commands:\n" "gpt swap <interface> <dev> <name1> <name2>\n" " - change all partitions named name1 to name2\n"
doc/README.gpt +21 -0
@@ -275,6 +275,27 @@ Some strings can be also used at the place of known GUID : They are also used to display the type of partition in "part list" command. +Identifying Partitions in U-Boot: +================================= + +Two subcommands may be used to identify partitions by their label. This can be +useful for determining which partition to use or for setting boot arguments. +The 'gpt part-uuid' command looks up a partition UUID for a given label and +stores it in an environment variable. The 'gpt part-num' command looks up a +partition number for a given label and stores it in an environment variable. +The first partition with a matching label is used. + +For example, to find the UUID of a partition named 'rootfs0' and then use it +for boot arguments: + +U-BOOT> gpt part-uuid mmc 0 rootfs0 rootfsuuid +U-BOOT> setenv bootargs root=PARTUUID=${rootfsuuid} + +Or, for example, to find the partition number for a partition named 'kernel' +and load a file from it: + +U-BOOT> gpt part-num mmc 0 kernel kernelnum +U-BOOT> fatload mmc 0:${kernelnum} ${loadaddr} zImage Useful info: ============
Signature · 1 line
2.13.6
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 7 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>
Why not use the 'part' cmd? it provides it.
Signature · 3 lines
Otavio Salvador O.S. Systems http://www.ossystems.com.br http://code.ossystems.com.br Mobile: +55 (53) 9981-7854 Mobile: +1 (347) 903-9750
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Otavio,
Quoted 8 lines · Otavio Salvador
Quoted 7 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there. I'll investigate and see if I can use it for what I'm trying to do, it looks like it should work.
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Andrey,
Quoted 17 lines
Hi Otavio,
Quoted 13 lines · Otavio Salvador
Quoted 11 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Quoted 6 lines
Quoted 3 lines
Quoted 1 line
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Quoted 6 lines
I'll investigate and see if I
can use it for what I'm trying to do, it looks like it should work.
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PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 21 lines · Lukasz Majewski
Hi Andrey,
Quoted 19 lines
Hi Otavio,
Quoted 15 lines · Otavio Salvador
Quoted 12 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>
Quoted 7 lines
Quoted 4 lines
Quoted 1 line
Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 26 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 24 lines · Lukasz Majewski
Hi Andrey,
Quoted 22 lines
Hi Otavio,
Quoted 17 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Quoted 7 lines
Quoted 5 lines
Quoted 2 lines
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Signature · 10 lines
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PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Lukasz,
Quoted 32 lines · Lukasz Majewski
Quoted 29 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 27 lines · Lukasz Majewski
Hi Andrey,
Quoted 24 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 6 lines
Quoted 4 lines
Quoted 2 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work:
1. the "part" command uses part_get_info() and in turn gets a partition driver and can call print() there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.
2. "part uuid" blk_get_device_part_str() which in turn can get information but referenced by partition number (and only partition number, due to how part_get_info() works). There's nothing at the 'part' layer tying a label to a number though so one would already need to know the number, which is the problem I'm trying to solve.
This layering keeps partitioning generalized and decoupled from the underlying partition "driver" but there's no concept of a label in the "driver" API. I'm not sure if it's reasonable to extend it since part_get_info() and similar really don't have a way to map labels at this layer so perhaps extending the GPT-specific command is the only reasonable approach?
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Andrey,
Quoted 43 lines
Hi Lukasz,
Quoted 32 lines · Lukasz Majewski
Quoted 29 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 27 lines · Lukasz Majewski
Hi Andrey,
Quoted 24 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 6 lines
Quoted 4 lines
Quoted 2 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 7 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work:
1. the "part" command usespart_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.
Maybe you can set some env variable with proper data?
For example, please refer to ./cmd/part.c do_part_start() function.
Example call from envs (include/configs/display5.h):
"part start mmc ${mmcdev} ${kernel_part} lba_start; " \Quoted 16 lines
2. "part uuid"
blk_get_device_part_str()which in turn can get information but referenced by partition number (and only partition number, due to howpart_get_info()works). There's nothing at the 'part' layer tying a label to a number though so one would already need to know the number, which is the problem I'm trying to solve.This layering keeps partitioning generalized and decoupled from the underlying partition "driver" but there's no concept of a label in the "driver" API. I'm not sure if it's reasonable to extend it since
part_get_info()and similar really don't have a way to map labels at this layer so perhaps extending the GPT-specific command is the only reasonable approach?
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PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Lukasz,
Quoted 53 lines · Lukasz Majewski
Hi Andrey,
Quoted 43 lines
Hi Lukasz,
Quoted 32 lines · Lukasz Majewski
Quoted 29 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 27 lines · Lukasz Majewski
Hi Andrey,
Quoted 24 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 6 lines
Quoted 4 lines
Quoted 2 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 7 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work:
1. the "part" command usespart_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.
Quoted 7 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; " \
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Andrey,
Quoted 66 lines
Hi Lukasz,
Quoted 54 lines · Lukasz Majewski
Hi Andrey,
Quoted 43 lines
Hi Lukasz,
Quoted 32 lines · Lukasz Majewski
Quoted 29 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 27 lines · Lukasz Majewski
Hi Andrey,
Quoted 24 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 6 lines
Quoted 4 lines
Quoted 2 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 8 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work:
1. the "part" command usespart_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.Quoted 7 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; " \
Quoted 6 lines
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
Please correct me if I'm wrong - you need the starting LBA of the partition named e.g. "FOO" in gpt ?
Conceptually it would be correct to have:
part start <interface> <dev> <NAME - e.g.'FOO'> <env to set> gpt start <interface> <dev> <NAME- e.g. 'FOO'> <env to set>
If your code is really _small_ and can be used only with GPT, then lets go for the second option.
Signature · 10 lines
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PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 78 lines · Lukasz Majewski
Hi Andrey,
Quoted 66 lines
Hi Lukasz,
Quoted 54 lines · Lukasz Majewski
Hi Andrey,
Quoted 43 lines
Hi Lukasz,
Quoted 32 lines · Lukasz Majewski
Quoted 29 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 27 lines · Lukasz Majewski
Hi Andrey,
Quoted 24 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 6 lines
Quoted 4 lines
Quoted 2 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 8 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work:
1. the "part" command usespart_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.Quoted 7 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; " \Quoted 6 lines
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
Please correct me if I'm wrong - you need the starting LBA of the partition named e.g. "FOO" in gpt ?
Quoted 7 lines
Conceptually it would be correct to have:
part start <interface> <dev> <NAME - e.g.'FOO'> <env to set> gpt start <interface> <dev> <NAME- e.g. 'FOO'> <env to set>
If your code is really _small_ and can be used only with GPT, then lets go for the second option.
The use cases I have in mind:
1. determine which root file system to use by label, let's say "rootfs1" and pass its UUID to the Linux kernel via the command line,
ex: "PART-UUID=${uuid}". To do this we need a way to ask for a UUID corresponding to a label in the partition table (given duplicate labels, assume it gives us the first or last match).
2. determine which file system to load a file from (ex: fatload) given a label. I'm not sure that the starting LBA is helpful here, we really are looking to map a label to a partition number in the table.
The implementation of "part start" interprets the argument as a partition number, so I can get the stating LBA if I know the partition number but I don't see a way (via cmd/disk.c) to get anything useful if all I know is a label, and that is what I'm trying to solve.
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Andrey,
Quoted 92 lines
Quoted 82 lines · Lukasz Majewski
Hi Andrey,
Quoted 70 lines
Hi Lukasz,
Quoted 57 lines · Lukasz Majewski
Hi Andrey,
Quoted 46 lines
Hi Lukasz,
Quoted 34 lines · Lukasz Majewski
Quoted 31 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 29 lines · Lukasz Majewski
Hi Andrey,
Quoted 26 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 8 lines
Quoted 6 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 7 lines
Quoted 5 lines
Quoted 3 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 8 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work: 1. the "part" command uses
part_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.Quoted 8 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; " \Quoted 6 lines
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
Please correct me if I'm wrong - you need the starting LBA of the partition named e.g. "FOO" in gpt ?
Quoted 7 lines
Conceptually it would be correct to have:
part start <interface> <dev> <NAME - e.g.'FOO'> <env to set> gpt start <interface> <dev> <NAME- e.g. 'FOO'> <env to set>
If your code is really _small_ and can be used only with GPT, then lets go for the second option.
Quoted 7 lines
The use cases I have in mind:
1. determine which root file system to use by label, let's say "rootfs1" and pass its UUID to the Linux kernel via the command line,
ex: "PART-UUID=${uuid}". To do this we need a way to ask for a UUID corresponding to a label in the partition table (given duplicate labels, assume it gives us the first or last match).
I see. I thought that you need start LBA.
Quoted 1 line
From your use case it seems like extending the 'gpt' command is the
right thing to do - since already some uuid handling is done there.
Quoted 2 lines
2. determine which file system to load a file from (ex: fatload) given a label.
There is a group of generic commands - like load, ls, etc.
Quoted 2 lines
I'm not sure that the starting LBA is helpful here, we really are looking to map a label to a partition number in the table.
If you are using GPT, then you also may want to extend the 'gpt' command -> iterate through PTEs and when label matched, return the part number. With it you can use e.g. load mmc 0 <part> file.
Quoted 5 lines
The implementation of "part start" interprets the argument as a partition number, so I can get the stating LBA if I know the partition number but I don't see a way (via
cmd/disk.c) to get anything useful if all I know is a label, and that is what I'm trying to solve.
Signature · 10 lines
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PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 102 lines · Lukasz Majewski
Hi Andrey,
Quoted 92 lines
Quoted 82 lines · Lukasz Majewski
Hi Andrey,
Quoted 70 lines
Hi Lukasz,
Quoted 57 lines · Lukasz Majewski
Hi Andrey,
Quoted 46 lines
Hi Lukasz,
Quoted 34 lines · Lukasz Majewski
Quoted 31 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 29 lines · Lukasz Majewski
Hi Andrey,
Quoted 26 lines
Hi Otavio,
Quoted 10 lines · Otavio Salvador
Quoted 8 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 8 lines
Quoted 6 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 7 lines
Quoted 5 lines
Quoted 3 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 8 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work: 1. the "part" command uses
part_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.Quoted 8 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; " \Quoted 6 lines
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
Please correct me if I'm wrong - you need the starting LBA of the partition named e.g. "FOO" in gpt ?
Quoted 7 lines
Conceptually it would be correct to have:
part start <interface> <dev> <NAME - e.g.'FOO'> <env to set> gpt start <interface> <dev> <NAME- e.g. 'FOO'> <env to set>
If your code is really _small_ and can be used only with GPT, then lets go for the second option.
Quoted 7 lines
The use cases I have in mind:
1. determine which root file system to use by label, let's say "rootfs1" and pass its UUID to the Linux kernel via the command line,
ex: "PART-UUID=${uuid}". To do this we need a way to ask for a UUID corresponding to a label in the partition table (given duplicate labels, assume it gives us the first or last match).
Quoted 4 lines
I see. I thought that you need start LBA.
From your use case it seems like extending the 'gpt' command is the right thing to do - since already some uuid handling is done there.
In that case would you please let me know if the patch I sent is reasonable?
Quoted 4 lines
Quoted 2 lines
2. determine which file system to load a file from (ex: fatload) given a label.
There is a group of generic commands - like load, ls, etc.
It seems that the lowest common denominator for these is indeed the partition number (then they can talk to the disk driver) so adding a way to map labels to that number (as in my original patch) may be useful, the user's script can then use these commands once it learns that information via the gpt command.
Quoted 6 lines
Quoted 2 lines
I'm not sure that the starting LBA is helpful here, we really are looking to map a label to a partition number in the table.
If you are using GPT, then you also may want to extend the 'gpt' command -> iterate through PTEs and when label matched, return the part number. With it you can use e.g. load mmc 0 <part> file.
Right, exactly. For that I added "gpt part-num" in the patch.
Quoted 12 lines
Quoted 5 lines
The implementation of "part start" interprets the argument as a partition number, so I can get the stating LBA if I know the partition number but I don't see a way (via
cmd/disk.c) to get anything useful if all I know is a label, and that is what I'm trying to solve.--
Best regards,�ukasz Majewski
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Hi Andrey,
Please resent it to u-boot ML.
Quoted 149 lines
Quoted 105 lines · Lukasz Majewski
Hi Andrey,
Quoted 95 lines
Quoted 85 lines · Lukasz Majewski
Hi Andrey,
Quoted 72 lines
Hi Lukasz,
Quoted 59 lines · Lukasz Majewski
Hi Andrey,
Quoted 48 lines
Hi Lukasz,
Quoted 36 lines · Lukasz Majewski
Quoted 33 lines · On Thu, 9 Nov 2017 07:34:44 -0800 Andrey Yurovsky <[email protected]> wrote:
Quoted 31 lines · Lukasz Majewski
Hi Andrey,
Quoted 28 lines
Hi Otavio,
Quoted 16 lines · Otavio Salvador
Quoted 14 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition
UUID or number given the partition label, for
instance some systems use the partition label to
indicate the purpose of the partition (such as
"rootfs0" being the 0th root file system in an A/B
image scheme).Add "gpt part-uuid" to retrieve the partition UUID
for a given label and "gpt part-num" to retrieve the
partition number for a given label along with some
documentation.Quoted 4 lines
Quoted 2 lines
Signed-off-by: Andrey Yurovsky
<[email protected]>Why not use the 'part' cmd? it provides it.
Sorry, I missed the part cmd, it doesn't seem to be documented in doc/ and it's unclear what <dev> means there.
Quoted 7 lines
Quoted 5 lines
Quoted 3 lines
If I may ask - Andrey, if you are now on this "topic" - would you dare to add some ./doc entry for 'part' command?
Yes, I will do that.
Thanks :-)
Quoted 8 lines
On further investigation I am not sure that it's possible to extend the part command to retrieve UUIDs by label because of the design of the partition type drivers. Here is how I understand it to work: 1. the "part" command uses
part_get_info()and in turn gets a partition driver and can callprint()there (which is how EFI/GPT disks are printed with "part list"). The right information (including label) is printed but it's not tied to the caller in any way.Quoted 8 lines
Maybe you can set some env variable with proper data?
For example, please refer to
./cmd/part.cdo_part_start()function.Example call from envs (
include/configs/display5.h):"part start mmc ${mmcdev} ${kernel_part} lba_start; "\
Quoted 7 lines
Again that assumes the partition is referred to by number, I need it to be by label, and the part/disk interface does not seem to have any way to utilize labels. Unfortunately it looks like my original approach with the gpt command is the only way to implement this with the current design (at least from what I see here). Please let me know if I've missed something. Thanks!
Please correct me if I'm wrong - you need the starting LBA of the partition named e.g. "FOO" in gpt ?
Quoted 7 lines
Conceptually it would be correct to have:
part start <interface> <dev> <NAME - e.g.'FOO'> <env to set> gpt start <interface> <dev> <NAME- e.g. 'FOO'> <env to set>
If your code is really _small_ and can be used only with GPT, then lets go for the second option.
Quoted 7 lines
The use cases I have in mind:
1. determine which root file system to use by label, let's say "rootfs1" and pass its UUID to the Linux kernel via the command line, ex: "PART-UUID=${uuid}". To do this we need a way to ask for a UUID corresponding to a label in the partition table (given duplicate labels, assume it gives us the first or last match).
Quoted 5 lines
I see. I thought that you need start LBA.
From your use case it seems like extending the 'gpt' command is the right thing to do - since already some uuid handling is done there.
In that case would you please let me know if the patch I sent is reasonable?
Quoted 4 lines
Quoted 2 lines
2. determine which file system to load a file from (ex: fatload) given a label.
There is a group of generic commands - like load, ls, etc.
It seems that the lowest common denominator for these is indeed the partition number (then they can talk to the disk driver) so adding a way to map labels to that number (as in my original patch) may be useful, the user's script can then use these commands once it learns that information via the gpt command.
Quoted 6 lines
Quoted 2 lines
I'm not sure that the starting LBA is helpful here, we really are looking to map a label to a partition number in the table.
If you are using GPT, then you also may want to extend the 'gpt' command -> iterate through PTEs and when label matched, return the part number. With it you can use e.g. load mmc 0 <part> file.
Right, exactly. For that I added "gpt part-num" in the patch.
Quoted 13 lines
Quoted 6 lines
The implementation of "part start" interprets the argument as a partition number, so I can get the stating LBA if I know the partition number but I don't see a way (via
cmd/disk.c) to get anything useful if all I know is a label, and that is what I'm trying to solve.--
Best regards,Łukasz Majewski
Signature · 10 lines
Best regards, Łukasz Majewski -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 195 bytes Desc: OpenPGP digital signature URL: <http://lists.denx.de/pipermail/u-boot/attachments/20171211/0364f933/attachment.sig>
PATCH 1/1 gpt: add part-uuid and part-num subcommands
In reply to Otavio SalvadorQuoted 8 lines · Otavio Salvador
Quoted 7 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 8 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
The use case is, given a label, find the UUID and/or the partition number. I see that 'part' can give me the UUID if I knew the partition number, it can print the whole table (but I don't think I can use that output cleanly), and it can list the partition numbers. I don't think I can solve my problem with 'part' as-is unless I have missed something.
If that's the case would it be alright to add these subcommands to 'part'? Thank you again,
-Andrey
PATCH 1/1 gpt: add part-uuid and part-num subcommands
Quoted 20 lines · Andrey Yurovsky
Quoted 9 lines · Otavio Salvador
Quoted 7 lines · your name
From: Andrey Yurovsky <[email protected]>
It is useful to be able to retrieve a partition UUID or number given the partition label, for instance some systems use the partition label to indicate the purpose of the partition (such as "rootfs0" being the 0th root file system in an A/B image scheme).
Quoted 7 lines
Quoted 5 lines
Add "gpt part-uuid" to retrieve the partition UUID for a given label and "gpt part-num" to retrieve the partition number for a given label along with some documentation.
Signed-off-by Andrey Yurovsky <[email protected]>Why not use the 'part' cmd? it provides it.
Quoted 8 lines
The use case is, given a label, find the UUID and/or the partition number. I see that 'part' can give me the UUID if I knew the partition number, it can print the whole table (but I don't think I can use that output cleanly), and it can list the partition numbers. I don't think I can solve my problem with 'part' as-is unless I have missed something.
If that's the case would it be alright to add these subcommands to 'part'? Thank you again,
It looks to be the best approach for me.
Signature · 3 lines
Otavio Salvador O.S. Systems http://www.ossystems.com.br http://code.ossystems.com.br Mobile: +55 (53) 9981-7854 Mobile: +1 (347) 903-9750