Introduces a new env var which specifies which device is the rootfs device to
be used in Linux, passed to Linux via bootargs, identified by the rootfs
partition's PARTUUID.
global.bootm.root_dev supplements global.bootm.appendroot, in that it
overrides appendroot's naïve default, which picks the partition that the
kernel resides on (global.bootm.image).
Example:
detect mmc2
global.bootm.image='/mnt/mmc2.0/zImage'
global.bootm.appendroot=1
global.bootm.root_dev=/dev/mmc2.1
boot mmc
Signed-off-by: Robert Karszniewicz <r.karszniewicz@xxxxxxxxx>
---
Changes from v1:
- minor commit message change
Changes from RFC v2:
- replaced path_get_linux_rootarg("invalid") by ERR_PTR(-EINVAL)
- added error messages. (I've made them mutually exclusive to prevent
NULL-pointer dereference)
common/bootm.c | 25 +++++++++++++++++++++++--
include/bootm.h | 2 ++
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/common/bootm.c b/common/bootm.c
index 8fec1ee34dd8..7f951172ccf5 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -64,6 +64,7 @@ void bootm_data_init_defaults(struct bootm_data *data)
getenv_ul("global.bootm.image.loadaddr", &data->os_address);
getenv_ul("global.bootm.initrd.loadaddr", &data->initrd_address);
data->initrd_file = getenv_nonempty("global.bootm.initrd");
+ data->root_dev = getenv_nonempty("global.bootm.root_dev");
data->verify = bootm_get_verify_mode();
data->appendroot = bootm_appendroot;
data->provide_machine_id = bootm_provide_machine_id;
@@ -655,7 +656,25 @@ int bootm_boot(struct bootm_data *bootm_data)
if (bootm_data->appendroot) {
char *rootarg;
- rootarg = path_get_linux_rootarg(data->os_file);
+ if (bootm_data->root_dev) {
+ const char *root_dev_name = devpath_to_name(bootm_data->root_dev);
+ const struct cdev *root_cdev = cdev_by_name(root_dev_name);
+
+ if (root_cdev && root_cdev->partuuid[0] != 0) {
+ rootarg = basprintf("root=PARTUUID=%s", root_cdev->partuuid);
+ } else {
+ rootarg = ERR_PTR(-EINVAL);
+
+ if (!root_cdev)
+ pr_err("no cdev found for %s, cannot set root= option\n",
+ root_dev_name);
+ else if (!root_cdev->partuuid[0])
+ pr_err("%s doesn't have a PARTUUID, cannot set root= option\n",
+ root_dev_name);
+ }
+ } else {
+ rootarg = path_get_linux_rootarg(data->os_file);
+ }
if (!IS_ERR(rootarg)) {
printf("Adding \"%s\" to Kernel commandline\n", rootarg);
globalvar_add_simple("linux.bootargs.bootm.appendroot",
@@ -742,6 +761,7 @@ static int bootm_init(void)
globalvar_add_simple("bootm.image", NULL);
globalvar_add_simple("bootm.image.loadaddr", NULL);
globalvar_add_simple("bootm.oftree", NULL);
+ globalvar_add_simple("bootm.root_dev", NULL);
globalvar_add_simple("bootm.tee", NULL);
globalvar_add_simple_bool("bootm.appendroot", &bootm_appendroot);
globalvar_add_simple_bool("bootm.provide_machine_id", &bootm_provide_machine_id);
@@ -771,5 +791,6 @@ BAREBOX_MAGICVAR_NAMED(global_bootm_oftree, global.bootm.oftree, "bootm default
BAREBOX_MAGICVAR_NAMED(global_bootm_tee, global.bootm.tee, "bootm default tee image");
BAREBOX_MAGICVAR_NAMED(global_bootm_verify, global.bootm.verify, "bootm default verify level");
BAREBOX_MAGICVAR_NAMED(global_bootm_verbose, global.bootm.verbose, "bootm default verbosity level (0=quiet)");
-BAREBOX_MAGICVAR_NAMED(global_bootm_appendroot, global.bootm.appendroot, "Add root= option to Kernel to mount rootfs from the device the Kernel comes from");
+BAREBOX_MAGICVAR_NAMED(global_bootm_appendroot, global.bootm.appendroot, "Add root= option to Kernel to mount rootfs from the device the Kernel comes from (default, device can be overridden via global.bootm.root_dev)");
+BAREBOX_MAGICVAR_NAMED(global_bootm_root_dev, global.bootm.root_dev, "bootm default root device (overrides default device in global.bootm.appendroot)");
BAREBOX_MAGICVAR_NAMED(global_bootm_provide_machine_id, global.bootm.provide_machine_id, "If true, add systemd.machine_id= with value of global.machine_id to Kernel");
diff --git a/include/bootm.h b/include/bootm.h
index 7782de7a476d..3628a7eea5b9 100644
--- a/include/bootm.h
+++ b/include/bootm.h
@@ -18,6 +18,7 @@ struct bootm_data {
const char *initrd_file;
const char *oftree_file;
const char *tee_file;
+ const char *root_dev;
int verbose;
enum bootm_verify verify;
bool force;
@@ -25,6 +26,7 @@ struct bootm_data {
/*
* appendroot - if true, try to add a suitable root= Kernel option to
* mount the rootfs from the same device as the Kernel comes from.
+ * The default rootfs device can be overridden with root_dev.
*/
bool appendroot;
/*
--
2.7.4
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