Re: [PATCH] cmd: gpt: Add option to write GPT partitions to environment variable

On 2/25/21 7:56 PM, Farhan Ali wrote:

This change would enhance the existing 'gpt read' command to allow (optionally) writing of the read GPT partitions to an environment variable. This would allow users to easily change the partition settings and then simply reuse the variable in the 'gpt write' and 'gpt verify' commands.

Signed-off-by: Farhan Ali farhan.ali@broadcom.com

Hello Farhan,

It is unclear what your use case is.

'gpt read' already reads the data into a data structure for manipulation. See doc/README.gpt.

Please, provide an example showing how you will use the variable.

---

Cc: Simon Glass sjg@chromium.org Cc: Heinrich Schuchardt xypron.glpk@gmx.de Cc: Corneliu Doban cdoban@broadcom.com Cc: Rayagonda Kokatanur rayagonda.kokatanur@broadcom.com

cmd/gpt.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/cmd/gpt.c b/cmd/gpt.c index 76a95ad..12d0551 100644 --- a/cmd/gpt.c +++ b/cmd/gpt.c @@ -350,17 +350,46 @@ static int get_gpt_info(struct blk_desc *dev_desc) }

/* a wrapper to test get_gpt_info */ -static int do_get_gpt_info(struct blk_desc *dev_desc) +static int do_get_gpt_info(struct blk_desc *dev_desc, char * const namestr) {

• int ret;

• int numparts;
• numparts = get_gpt_info(dev_desc);
• if (numparts > 0) {

• if (namestr) {
  

If the parameter is missing, the caller passes random bytes and not NULL. So this check does not work.

• 	char disk_guid[UUID_STR_LEN + 1];
  

• 	char *partitions_list;
  

• 	int partlistlen;
  

• 	int ret = -1;
  

• 	ret = get_disk_guid(dev_desc, disk_guid);
  

• 	if (ret < 0)
  

• 		return ret;
  

• 	partlistlen = calc_parts_list_len(numparts);
  

• 	partitions_list = malloc(partlistlen);
  

• 	if (!partitions_list) {
  

• 		del_gpt_info();
  

• 		return -ENOMEM;
  

• 	}
  

• 	memset(partitions_list, '\0', partlistlen);
  

• 	ret = create_gpt_partitions_list(numparts, disk_guid,
  

• 					 partitions_list);
  

• 	if (ret < 0)
  

• 		printf("Error: Could not create partition list string!\n");
  

• 	else
  

• 		env_set(namestr, partitions_list);
  
  

• ret = get_gpt_info(dev_desc);
• if (ret > 0) {

• print_gpt_info();
  

• 	free(partitions_list);
  

• } else {
  

• 	print_gpt_info();
  

• }
  

  del_gpt_info(); return 0; }

• return ret;

• return numparts; } #endif

@@ -982,7 +1011,7 @@ static int do_gpt(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) ret = do_disk_guid(blk_dev_desc, argv[4]); #ifdef CONFIG_CMD_GPT_RENAME } else if (strcmp(argv[1], "read") == 0) {

• ret = do_get_gpt_info(blk_dev_desc);
  

• ret = do_get_gpt_info(blk_dev_desc, argv[4]);
  

You have to check argc to know if argv[4] exists and pass argv[4] or NULL accordingly.

} 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]); @@ -1028,8 +1057,9 @@ U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt, " gpt guid mmc 0 varname\n" #ifdef CONFIG_CMD_GPT_RENAME "gpt partition renaming commands:\n"

• " gpt read <interface> <dev>\n"

• " gpt read <interface> <dev> [<varname>]\n" " - read GPT into a data structure for manipulation\n"
• " - read GPT partitions into environment variable\n"

Where is your update for doc/README.gpt?

Best regards

Heinrich

" gpt swap <interface> <dev> <name1> <name2>\n" " - change all partitions named name1 to name2\n" " and vice-versa\n"