How to let openbmc's kernel load jffs2 file system

[郁雷]

On Tue, Jul 14, 2020 at 9:34 AM 周 远清 <zhouyuanqing8 at outlook.com> wrote:
>
> Hello everyone,
>
> The rofs squashfs currently loaded by the kernel of openbmc is very inconvenient to debug because squashfs is a read-only file system. I made a jffs2 file system, after modifying the bootarg parameters of uboot, the kernel still loads squashfs.

By default the root (/) is mounted by an overlayfs, so the whole
rootfs is writable, see below:

    cow on / type overlay
(rw,relatime,lowerdir=run/initramfs/ro,upperdir=run/initramfs/rw/cow,workdir=run/initramfs/rw/work)

Be noted that the rwfs mounted at /run/initramfs/rw has a limited
size, so you could only put files with limited size.
For testing purposes, you could manually create overlayfs mount in
tmpfs, that way you could use the ramfs instead of rwfs, and it will
be cleaned after BMC reboot.

-- 
BRs,
Lei YU