Hi Denis,
On 6/5/26 5:39 AM, [email protected] wrote:
From: Denis Mukhin <[email protected]>
Enable extension for existing 'gpt' command to manipulate top 16
bits of GPT PTE attributes to assist ChromiumOS-style boot counters.
Follow the existing syntax for specifying <interface, device, partition>
tuple.
Signed-off-by: Denis Mukhin <[email protected]>
---
cmd/Kconfig | 8 +++++
cmd/gpt.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+)
diff --git a/cmd/Kconfig b/cmd/Kconfig
index c71c6824a196..83409e60da8b 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1319,6 +1319,14 @@ config CMD_GPT
Enable the 'gpt' command to ready and write GPT style partition
tables.
+config CMD_GPT_FLAGS
+ bool "GPT partition flags commands"
+ depends on CMD_GPT
+ select PARTITION_TYPE_GUID
+ help
+ Enables the GUID partition table attributes manipulation (bits 48:63)
+ in a ChromiumOS-style manner.
+
config CMD_GPT_RENAME
bool "GPT partition renaming commands"
depends on CMD_GPT
diff --git a/cmd/gpt.c b/cmd/gpt.c
index 205f696c8072..4d55cb588ac2 100644
--- a/cmd/gpt.c
+++ b/cmd/gpt.c
@@ -11,6 +11,9 @@
*/
#include <blk.h>
+#ifdef CONFIG_CMD_GPT_FLAGS
+#include <cros_flags.h>
+#endif
#include <env.h>
#include <log.h>
#include <malloc.h>
@@ -1116,6 +1119,64 @@ out:
}
#endif
+#ifdef CONFIG_CMD_GPT_FLAGS
+static int do_get_gpt_flags(struct blk_desc *desc, int partnum)
+{
+ u16 guid_flags;
+ int rc;
+
+ rc = read_disk_flags(desc, partnum, &guid_flags);
+ if (rc < 0) {
+ printf("ERROR: partnum %d: failed to read GPT flags: %d\n",
+ partnum, rc);
+ return CMD_RET_FAILURE;
+ }
+
+ printf("P=%d S=%d T=%d\n",
+ cros_flags_get_priority(guid_flags),
+ cros_flags_get_successful(guid_flags),
+ cros_flags_get_tries(guid_flags));
+
+ return 0;
+}
+
+static int do_set_gpt_flags(struct blk_desc *desc, int partnum,
+ const char *key, int value)
+{
+ u16 guid_flags;
+ int rc;
+
+ rc = read_disk_flags(desc, partnum, &guid_flags);
+ if (rc < 0) {
+ printf("ERROR: partnum %d: failed to read GPT flags: %d\n",
+ partnum, rc);
+ return CMD_RET_FAILURE;
+ }
+
+ if (!strcmp(key, "set-flags")) {
+ guid_flags = (u16)(value & 0xffff);
+ } else if (!strcmp(key, "set-priority")) {
+ guid_flags = cros_flags_set_priority(guid_flags, value);
+ } else if (!strcmp(key, "set-successful")) {
+ guid_flags = cros_flags_set_successful(guid_flags, value);
+ } else if (!strcmp(key, "set-tries")) {
+ guid_flags = cros_flags_set_tries(guid_flags, value);
+ } else {
+ printf("ERROR: unsupported command '%s'\n", key);
+ return CMD_RET_FAILURE;
CMD_RET_USAGE
+ }
+
+ rc = write_disk_flags(desc, partnum, guid_flags);
+ if (rc < 0) {
+ pr_err("ERROR: partnum %d: failed to write GPT flags: %d\n",
+ partnum, rc);
+ return CMD_RET_FAILURE;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_CMD_GPT_FLAGS */
+
/**
* do_gpt(): Perform GPT operations
*
@@ -1176,6 +1237,23 @@ static int do_gpt(struct cmd_tbl *cmdtp, int flag, int
argc, char *const argv[])
ret = do_rename_gpt_parts(blk_dev_desc, argv[1], argv[4],
argv[5]);
} else if ((strcmp(argv[1], "set-bootable") == 0)) {
ret = gpt_set_bootable(blk_dev_desc, argv[4]);
+#endif
+#ifdef CONFIG_CMD_GPT_FLAGS
+ } else if (!strcmp(argv[1], "get-flags")) {
+ if (argc < 5)
+ return CMD_RET_FAILURE;
CMD_RET_USAGE
+ ret = do_get_gpt_flags(blk_dev_desc,
+ simple_strtol(argv[4], NULL, 0));
+ } else if (!strcmp(argv[1], "set-flags") ||
+ !strcmp(argv[1], "set-priority") ||
+ !strcmp(argv[1], "set-successful") ||
+ !strcmp(argv[1], "set-tries")) {
+ if (argc < 6)
+ return CMD_RET_FAILURE;
CMD_RET_USAGE
+ ret = do_set_gpt_flags(blk_dev_desc, /* argv[2,3] */
+ simple_strtol(argv[4], NULL, 0),
+ argv[1],
+ simple_strtol(argv[5], NULL, 0));
#endif
} else {
return CMD_RET_USAGE;
@@ -1237,4 +1315,23 @@ U_BOOT_CMD(gpt, CONFIG_SYS_MAXARGS, 1, do_gpt,
" gpt set-bootable mmc 0 boot_a,boot_b\n"
" gpt transpose mmc 0 1 2\n"
#endif
+#ifdef CONFIG_CMD_GPT_FLAGS
+ "gpt partition boot flag manipulation:\n"
+ " gpt get-flags <interface> <dev> <partid>\n"
+ " - read top 16-bit of partition attributes (bits 48:63)\n"
+ " gpt set-flags <interface> <dev> <partid> <flags-in-hex>\n"
+ " - write top 16-bit of partition attributes (bits 48:63)\n"
+ " gpt set-successful <interface> <dev> <partid> {0,1}\n"
+ " - set 'boot successful' bit\n"
+ " gpt set-priority <interface> <dev> <partid> [0..15]\n"
+ " - set priority; 0 - non-bootable\n"
+ " gpt set-tries <interface> <dev> <partid> [0..15]\n"
+ " - set tries (boot counter)\n"
These are the first subcommands that use "partid" as an argument
identifier, can you rather use a name we've already used in another
subcommand (if applicable).
I'm wondering if we need the additional get-/set- prefix? It could be
enough to pass a 4th argument to know whether we want a get or a set.
Either way is fine I guess.
I really recommend to not go with decimal values, U-Boot has a mix of
hexadecimal and base 10 numbers all over the place but we typically say
the default should be hex, c.f.
https://docs.u-boot-project.org/en/latest/usage/cmdline.html#representing-numbers
In any case, the base needs to be made explicit in doc/usage/cmd/gpt.rst
so there is no possible confusion.
+ " Example usage:\n"
+ " gpt get-flags nvme 0 1\n"
+ " gpt set-flags nvme 0 1 0xff\n"
+ " gpt set-priority nvme 0 1 0\n"
+ " gpt set-successful nvme 0 1 1\n"
+ " gpt set-tries nvme 0 1 15\n"
I don't think we want examples in the help text in U-Boot, it'll
unnecessarily increase the size of the binary. I see we have it for
other gpt subcommands so maybe that's fine /me shrugs.
We absolutely do need an update to doc/usage/cmd/gpt.rst to reflect
those changes though (and there you can have examples!).
Cheers,
Quentin
