[PATCH v2 3/4] bootstd: Add command to enable setting of bootmeth specific properties
Martyn Welch
martyn.welch at collabora.com
Wed Oct 9 15:15:40 CEST 2024
We have previously added logic to allow a "fallback" option to be
specified in the extlinux configuration. Provide a command that allows
us to set this as the preferred default option when booting.
Combined with the bootcount functionality, this allows the "altbootcmd"
to provide a means of falling back to a previously known good state
after a failed update. For example, if "bootcmd" is set to:
bootflow scan -lb
We would set "altbootcmd" to:
bootmeth set extlinux fallback 1; bootflow scan -lb
Causing the boot process to boot from the fallback option.
Reviewed-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Martyn Welch <martyn.welch at collabora.com>
---
Changes since v1:
- Addition of documentation of bootmeth sub command and bootstd
feature.
boot/bootmeth-uclass.c | 25 +++++++++++
boot/bootmeth_extlinux.c | 73 +++++++++++++++++++++++++++++++-
cmd/bootmeth.c | 25 ++++++++++-
doc/develop/bootstd/overview.rst | 10 ++++-
doc/usage/cmd/bootmeth.rst | 38 ++++++++++++++++-
include/bootmeth.h | 31 ++++++++++++++
6 files changed, 196 insertions(+), 6 deletions(-)
diff --git a/boot/bootmeth-uclass.c b/boot/bootmeth-uclass.c
index c0abadef97..5b5fea39b3 100644
--- a/boot/bootmeth-uclass.c
+++ b/boot/bootmeth-uclass.c
@@ -251,6 +251,31 @@ int bootmeth_set_order(const char *order_str)
return 0;
}
+int bootmeth_set_property(const char *name, const char *property, const char *value)
+{
+ int ret;
+ int len;
+ struct udevice *dev;
+ const struct bootmeth_ops *ops;
+
+ len = strlen(name);
+
+ ret = uclass_find_device_by_namelen(UCLASS_BOOTMETH, name, len,
+ &dev);
+ if (ret) {
+ printf("Unknown bootmeth '%s'\n", name);
+ return ret;
+ }
+
+ ops = bootmeth_get_ops(dev);
+ if (!ops->set_property) {
+ printf("set_property not found\n");
+ return -ENODEV;
+ }
+
+ return ops->set_property(dev, property, value);
+}
+
int bootmeth_setup_fs(struct bootflow *bflow, struct blk_desc *desc)
{
int ret;
diff --git a/boot/bootmeth_extlinux.c b/boot/bootmeth_extlinux.c
index 26c61a65e2..be8fbf4df6 100644
--- a/boot/bootmeth_extlinux.c
+++ b/boot/bootmeth_extlinux.c
@@ -21,6 +21,39 @@
#include <mmc.h>
#include <pxe_utils.h>
+struct extlinux_plat {
+ bool use_fallback;
+};
+
+enum extlinux_option_type {
+ EO_FALLBACK,
+ EO_INVALID
+};
+
+struct extlinux_option {
+ char *name;
+ enum extlinux_option_type option;
+};
+
+static const struct extlinux_option options[] = {
+ {"fallback", EO_FALLBACK},
+ {NULL, EO_INVALID}
+};
+
+static enum extlinux_option_type get_option(const char *option)
+{
+ int i = 0;
+
+ while (options[i].name) {
+ if (!strcmp(options[i].name, option))
+ return options[i].option;
+
+ i++;
+ }
+
+ return EO_INVALID;
+};
+
static int extlinux_get_state_desc(struct udevice *dev, char *buf, int maxsize)
{
if (IS_ENABLED(CONFIG_SANDBOX)) {
@@ -142,14 +175,18 @@ static int extlinux_boot(struct udevice *dev, struct bootflow *bflow)
struct cmd_tbl cmdtp = {}; /* dummy */
struct pxe_context ctx;
struct extlinux_info info;
+ struct extlinux_plat *plat;
ulong addr;
int ret;
addr = map_to_sysmem(bflow->buf);
info.dev = dev;
info.bflow = bflow;
+
+ plat = dev_get_plat(dev);
+
ret = pxe_setup_ctx(&ctx, &cmdtp, extlinux_getfile, &info, true,
- bflow->fname, false, false);
+ bflow->fname, false, plat->use_fallback);
if (ret)
return log_msg_ret("ctx", -EINVAL);
@@ -160,6 +197,38 @@ static int extlinux_boot(struct udevice *dev, struct bootflow *bflow)
return 0;
}
+static int extlinux_set_property(struct udevice *dev, const char *property, const char *value)
+{
+ struct extlinux_plat *plat;
+ static enum extlinux_option_type option;
+
+ plat = dev_get_plat(dev);
+
+ option = get_option(property);
+ if (option == EO_INVALID) {
+ printf("Invalid option\n");
+ return -EINVAL;
+ }
+
+ switch (option) {
+ case EO_FALLBACK:
+ if (!strcmp(value, "1")) {
+ plat->use_fallback = true;
+ } else if (!strcmp(value, "0")) {
+ plat->use_fallback = false;
+ } else {
+ printf("Unexpected value '%s'\n", value);
+ return -EINVAL;
+ }
+ break;
+ default:
+ printf("Unrecognised property '%s'\n", property);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int extlinux_bootmeth_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
@@ -176,6 +245,7 @@ static struct bootmeth_ops extlinux_bootmeth_ops = {
.read_bootflow = extlinux_read_bootflow,
.read_file = bootmeth_common_read_file,
.boot = extlinux_boot,
+ .set_property = extlinux_set_property,
};
static const struct udevice_id extlinux_bootmeth_ids[] = {
@@ -190,4 +260,5 @@ U_BOOT_DRIVER(bootmeth_1extlinux) = {
.of_match = extlinux_bootmeth_ids,
.ops = &extlinux_bootmeth_ops,
.bind = extlinux_bootmeth_bind,
+ .plat_auto = sizeof(struct extlinux_plat)
};
diff --git a/cmd/bootmeth.c b/cmd/bootmeth.c
index ebf8b7e253..2f41fa1bec 100644
--- a/cmd/bootmeth.c
+++ b/cmd/bootmeth.c
@@ -103,10 +103,31 @@ static int do_bootmeth_order(struct cmd_tbl *cmdtp, int flag, int argc,
return 0;
}
+static int do_bootmeth_set(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ int ret;
+
+ if (argc < 4) {
+ printf("Required parameters not provided\n");
+ return CMD_RET_FAILURE;
+ }
+
+ ret = bootmeth_set_property(argv[1], argv[2], argv[3]);
+ if (ret) {
+ printf("Failed (err=%d)\n", ret);
+ return CMD_RET_FAILURE;
+ }
+
+ return 0;
+}
+
U_BOOT_LONGHELP(bootmeth,
"list [-a] - list available bootmeths (-a all)\n"
- "bootmeth order [<bd> ...] - select bootmeth order / subset to use");
+ "bootmeth order [<bd> ...] - select bootmeth order / subset to use\n"
+ "bootmeth set <bootmeth> <property> <value> - set optional property");
U_BOOT_CMD_WITH_SUBCMDS(bootmeth, "Boot methods", bootmeth_help_text,
U_BOOT_SUBCMD_MKENT(list, 2, 1, do_bootmeth_list),
- U_BOOT_SUBCMD_MKENT(order, CONFIG_SYS_MAXARGS, 1, do_bootmeth_order));
+ U_BOOT_SUBCMD_MKENT(order, CONFIG_SYS_MAXARGS, 1, do_bootmeth_order),
+ U_BOOT_SUBCMD_MKENT(set, CONFIG_SYS_MAXARGS, 1, do_bootmeth_set));
diff --git a/doc/develop/bootstd/overview.rst b/doc/develop/bootstd/overview.rst
index c6f003851b..a2913cd47b 100644
--- a/doc/develop/bootstd/overview.rst
+++ b/doc/develop/bootstd/overview.rst
@@ -103,6 +103,12 @@ provide a `read_bootflow()` method which checks whatever bootdevs it likes, then
returns the bootflow, if found. Some of these bootmeths may be very slow, if
they scan a lot of devices.
+The extlinux bootmeth also allows for bootmeth specific configuration to be
+set. A bootmeth that wishes to support this provides the `set_property()`
+method. This allows string properties and values to be passed to the bootmeth.
+It is up to the bootmeth to determine what action to take when this method is
+called.
+
Boot process
------------
@@ -459,8 +465,8 @@ Three commands are available:
See :doc:`/usage/cmd/bootflow`
`bootmeth`
- Allow listing of available bootmethds and setting the order in which they
- are tried. See :doc:`/usage/cmd/bootmeth`
+ Allow listing of available bootmethds, setting the order in which they are
+ tried and bootmeth specific configuration. See :doc:`/usage/cmd/bootmeth`
.. _BootflowStates:
diff --git a/doc/usage/cmd/bootmeth.rst b/doc/usage/cmd/bootmeth.rst
index c3d2ec1574..4f899d92b2 100644
--- a/doc/usage/cmd/bootmeth.rst
+++ b/doc/usage/cmd/bootmeth.rst
@@ -12,7 +12,8 @@ Synopsis
::
bootmeth list [-a] - list selected bootmeths (-a for all)
- bootmeth order "[<bm> ...]" - select the order of bootmeths\n"
+ bootmeth order "[<bm> ...]" - select the order of bootmeths
+ bootmeth set <bootmeth> <property> <value> - set optional property
Description
@@ -112,3 +113,38 @@ which are not::
- 4 efi_mgr EFI bootmgr flow
----- --- ------------------ ------------------
(5 bootmeths)
+
+
+bootmeth set
+~~~~~~~~~~~~
+
+Allows setting of bootmeth specific configuration. This allows finer grain
+control over the boot process in specific instances.
+
+
+Supported Configuration Options
+-------------------------------
+
+The following configuration options are currently supported:
+
+======== =================== ====== ===============================
+Property Supported Bootmeths Values Description
+======== =================== ====== ===============================
+fallback extlinux 0 | 1 Enable or disable fallback path
+======== =================== ====== ===============================
+
+
+Bootmeth set Example
+--------------------
+
+With the bootcount functionality enabled, when the bootlimit is reached, the
+`altbootcmd` environment variable lists the command used for booting rather
+than `bootcmd`. We can set the fallback configuration to cause the fallback
+boot option to be preferred, to revert to a previous known working boot option
+after a failed update for example. So if `bootcmd` is set to::
+
+ bootflow scan -lb
+
+We would set "altbootcmd" to::
+
+ bootmeth set extlinux fallback 1; bootflow scan -lb
diff --git a/include/bootmeth.h b/include/bootmeth.h
index 4d8ca48efd..a08ebf005a 100644
--- a/include/bootmeth.h
+++ b/include/bootmeth.h
@@ -146,6 +146,22 @@ struct bootmeth_ops {
* something changes, other -ve on other error
*/
int (*boot)(struct udevice *dev, struct bootflow *bflow);
+
+ /**
+ * set_property() - set the bootmeth property
+ *
+ * This allows the setting of boot method specific properties to enable
+ * automated finer grain control of the boot process
+ *
+ * @name: String containing the name of the relevant boot method
+ * @property: String containing the name of the property to set
+ * @value: String containing the value to be set for the specified
+ * property
+ * Return: 0 if OK, -ENODEV if an unknown bootmeth or property is
+ * provided, -ENOENT if there are no bootmeth devices
+ */
+ int (*set_property)(struct udevice *dev, const char *property,
+ const char *value);
};
#define bootmeth_get_ops(dev) ((struct bootmeth_ops *)(dev)->driver->ops)
@@ -290,6 +306,21 @@ int bootmeth_setup_iter_order(struct bootflow_iter *iter, bool include_global);
*/
int bootmeth_set_order(const char *order_str);
+/**
+ * bootmeth_set_property() - Set the bootmeth property
+ *
+ * This allows the setting of boot method specific properties to enable
+ * automated finer grain control of the boot process
+ *
+ * @name: String containing the name of the relevant boot method
+ * @property: String containing the name of the property to set
+ * @value: String containing the value to be set for the specified property
+ * Return: 0 if OK, -ENODEV if an unknown bootmeth or property is provided,
+ * -ENOENT if there are no bootmeth devices
+ */
+int bootmeth_set_property(const char *name, const char *property,
+ const char *value);
+
/**
* bootmeth_setup_fs() - Set up read to read a file
*
--
2.45.2
More information about the U-Boot
mailing list