[PATCH 2/2] blspec: automatically append bootargs

[Sascha Hauer]

On Tue, May 26, 2015 at 02:46:21PM +0200, Marc Kleine-Budde wrote:
> From: Sascha Hauer <s.hauer at pengutronix.de>
> 
> When bootloader spec is used to boot devices it is often desirable
> to boot the same image from different media. Since the fs images
> need to contain the root= parameters to tell Linux where to boot
> from the images can't be identical on different media.
> 
> This patch changes this by introducing a 'appendroot' option for
> bootloader spec. If set to true, barebox will construct a Linux
> commandline option for the device the bootloader spec entry is found
> on.

This should have documentation in Documentation/user/booting-linux.rst.
(which currently lacks information that we can do bootloaderspec via NFS
aswell)

> +static int blspec_append_root(struct blspec_entry *entry)
> +{
> +	const char *appendroot;
> +	const char *rootarg;
> +	struct device_d *fsdev;
> +	int ret;
> +
> +	appendroot = blspec_entry_var_get(entry, "appendroot");
> +	if (!appendroot || strcmp(appendroot, "true"))
> +		return 0;
> +
> +	fsdev = get_dev_by_mountpath(entry->rootpath);
> +	if (!fsdev) {
> +		ret = -EINVAL;
> +		pr_err("Cannot get fs device for %s\n", entry->rootpath);
> +		goto err_out;
> +	}
> +
> +	rootarg = dev_get_param(fsdev, "linux.bootargs");

Better linux.root?

> --- a/drivers/mtd/ubi/kapi.c
> +++ b/drivers/mtd/ubi/kapi.c
> @@ -36,6 +36,7 @@ void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
>  	di->min_io_size = ubi->min_io_size;
>  	di->max_write_size = ubi->max_write_size;
>  	di->ro_mode = ubi->ro_mode;
> +	di->mtd = ubi->mtd;
>  }
>  EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
>  
> diff --git a/fs/fs.c b/fs/fs.c
> index a056d83d3d92..b8d3d3468f01 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -225,6 +225,19 @@ struct cdev *get_cdev_by_mountpath(const char *path)
>  	return fsdev->cdev;
>  }
>  
> +/*
> + * get_cdev_by_mountpath - return the cdev the given path
> + *                         is mounted on

s/get_cdev_by_mountpath/get_dev_by_mountpath/

> + */
> +struct device_d *get_dev_by_mountpath(const char *path)
> +{
> +	struct fs_device_d *fsdev;
> +
> +	fsdev = get_fsdevice_by_path(path);
> +
> +	return &fsdev->dev;
> +}
> +
>  char *get_mounted_path(const char *path)
>  {
>  	struct fs_device_d *fdev;
> diff --git a/fs/nfs.c b/fs/nfs.c
> index 2738c781d72b..ba00270a8b23 100644
> --- a/fs/nfs.c
> +++ b/fs/nfs.c
> @@ -1306,6 +1306,20 @@ static int nfs_stat(struct device_d *dev, const char *filename, struct stat *s)
>  	}
>  }
>  
> +static void nfs_set_rootarg(struct nfs_priv *npriv, struct device_d *dev)
> +{
> +	char *str;
> +	const char *ip;
> +
> +	ip = ip_to_string(npriv->server);
> +	str = asprintf("root=/dev/nfs nfsroot=%s:%s,v3,tcp",
> +			ip, npriv->path);

It would be nice to have the NFS options configurable. Maybe from a
global.linux.rootnfsopts variable?

Sascha

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