On 06/18/2015 09:43 AM, Sascha Hauer wrote:
> This patch makes it possible to automatically add a suitable root= option
> for booting Linux from the same filesystem on which the bootspec entry
> has been found. This adds an additional 'linux-appendroot' option to
> bootspec which if set to 'true' will cause barebox to automatically
> add a root= option. This currently works for NFS, UBIFS and regular
> block devices like ATA, SD/MMC using the root=PARTUUID= mechanism.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> Documentation/user/booting-linux.rst | 7 +++++++
> common/blspec.c | 29 ++++++++++++++++++++++++++++-
> 2 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/user/booting-linux.rst b/Documentation/user/booting-linux.rst
> index 6e7d155..39084e5 100644
> --- a/Documentation/user/booting-linux.rst
> +++ b/Documentation/user/booting-linux.rst
> @@ -205,6 +205,13 @@ compatible NFS URI string must be passed to the boot command:
>
> boot nfs://nfshost//path/
>
> +Additionally to the options defined in the original spec barebox understands the
> +``linux-appendroot`` option. This is a boolean value and if set to ``true`` barebox
> +will automatically append a ``root=`` string to the Linux commandline based on the
> +device where the entry is found on. This makes it possible to use the same rootfs
> +image on different devices without having to specify a different root= option each
> +time.
> +
> Network boot
> ------------
>
> diff --git a/common/blspec.c b/common/blspec.c
> index 3506388..742065e 100644
> --- a/common/blspec.c
> +++ b/common/blspec.c
> @@ -601,6 +601,29 @@ int blspec_scan_devicename(struct blspec *blspec, const char *devname)
> return blspec_scan_device(blspec, dev);
> }
>
> +static int blspec_append_root(struct blspec_entry *entry)
> +{
> + const char *appendroot;
> + char *rootarg;
> +
> + appendroot = blspec_entry_var_get(entry, "linux-appendroot");
> + if (!appendroot || strcmp(appendroot, "true"))
> + return 0;
> +
Can you move the following into a separate function outside of blspec.c
so that it can be used somewhere else, too?
> + rootarg = path_get_linux_rootarg(entry->rootpath);
> + if (IS_ERR(rootarg)) {
> + pr_err("Getting root argument for %s failed with: %s\n",
> + entry->rootpath, strerror(-PTR_ERR(rootarg)));
> + return PTR_ERR(rootarg);
> + }
> +
> + globalvar_add_simple("linux.bootargs.dyn.blspec.appendroot", rootarg);
> +
> + free(rootarg);
> +
> + return 0;
> +}
> +
> /*
> * blspec_boot - boot an entry
> *
> @@ -650,6 +673,10 @@ int blspec_boot(struct blspec_entry *entry, int verbose, int dryrun)
>
> globalvar_add_simple("linux.bootargs.dyn.blspec", options);
>
> + ret = blspec_append_root(entry);
> + if (ret)
> + goto err_out;
> +
> pr_info("booting %s from %s\n", blspec_entry_var_get(entry, "title"),
> entry->cdev ? dev_name(entry->cdev->dev) : "none");
>
> @@ -668,7 +695,7 @@ int blspec_boot(struct blspec_entry *entry, int verbose, int dryrun)
> ret = bootm_boot(&data);
> if (ret)
> pr_err("Booting failed\n");
> -
> +err_out:
> free((char *)data.oftree_file);
> free((char *)data.initrd_file);
> free((char *)data.os_file);
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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