[U-Boot] [RFC PATCH 2/2] fs: add partition switch libary, implement ls and fsload commands

[Tom Rini]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 10/11/12 09:57, Stephen Warren wrote:
> On 10/11/2012 10:47 AM, Tom Rini wrote:
>> On 10/10/12 17:05, Stephen Warren wrote:
>>> From: Stephen Warren <swarren at nvidia.com>
>> 
>>> Implement "ls" and "fsload" commands that act like 
>>> {fat,ext2}{ls,load}, and transparently handle either 
>>> file-system. This scheme could easily be extended to other 
>>> filesystem types; I only didn't do it for zfs because I don't 
>>> have any filesystems of that type.
>> 
>>> Signed-off-by: Stephen Warren <swarren at nvidia.com> --- There 
>>> are a couple FIXMEs in here:
>> 
>>> 1) In fs/fs.c, code is ifdef on CONFIG_CMD_FAT or 
>>> CONFIG_CMD_EXT2. This means that the new commands and code can
>>>  only be enabled if the "legacy" {fat,ext2}{ls,load} are 
>>> enabled. What we really want is CONFIG_FS_FAT and 
>>> CONFIG_FS_EXT2 to enable the filesystem code, and then 
>>> CONFIG_CMD_FAT, CONFIG_CMD_EXT2, CONFIG_CMD_FS to only affect 
>>> the command implementations. However, that would require
>>> making every include/config/*.h that sets the current defines
>>> also set more. I suppose that's a fairly mechanical change
>>> though, so easy enough to implement. Does that seem like a
>>> reasonable approach to people?
>> 
>> How about a new CONFIG_CMD_GENERIC_FS for the new ls/fsload (and
>>  any later commands like write that get added) and once most 
>> filesystems are converted we can think about a transition plan?
> 
> Certainly.
> 
> The issue is that the filesystem code itself is conditionally 
> included based on CONFIG_CMD_FAT and CONFIG_CMD_EXT4. This would 
> require that in order to use the new generic commands, you also
> had to support the old non-generic commands in order to get a
> linkable result. Perhaps that's fine for now, but by separating the
> existing CONFIG_CMD_FAT into two (CONFIG_CMD_FAT, CONFIG_FS_FAT),
> we could avoid that requirement. As Benoit mentioned, perhaps we
> could arrange that CONFIG_CMD_FAT selects CONFIG_FS_FAT somehow,
> although I haven't looked at U-Boot's configuration system to see
> if that's possible yet.

Since we don't have Kconfig right now, it's not really easy to do that
kind of thing.  I think once we have more filesystems converted we can
work out doing the mechanical separate of fs/ from common/ for fs code.

- -- 
Tom

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

iQIcBAEBAgAGBQJQdvxhAAoJENk4IS6UOR1WOFIP/0VjExqx5FZ+Lau4wFtV8dI0
v5+jfwDUtG0L3h/lTv9NJkX5j9duXJVOcAkB4hVeWFAqd/fSdI0mlajPvR1rpS/J
luYFvR/XdlIoQe65CbrKhFEzHH3pwcbYXd/Zz9wx2cvxmTz7NvbM3KZsvECPpYtO
CEqNClM2e5Q0ebE/XKZ5xG8qJVWZbs48i8kkmgHQHsiplGEdf7IzNgOqiSFL5rgF
DT6oRacoAzOLBwMo5/ssIiT04GgM+3Nac1UV/4GPKiNt62k4p6OfniUN4sL6N6Yl
oq8aFR3ZWGZgHdHO+y+pp+4MLAlvbv8PxMXHhw/ZCCHgLR9sodvWQl/Pn3C9TFTC
0LdYgMvft5FBBqffI+XuPMomdKYLmmHtAhlh7lly9L5GQYw8iU25cfXP8ZeBUOX+
aY4nX/Wp2s+vtXawWUVv01r0HRZZp3r6FJNAXWvE9m2cB+7HiZQD+nJvkV7ZZk7E
6WRdRlI8NTLn6Sfh42d6AzigsYfAm2Xwp6B1/gGix075E30yhB1KGdxs/SpQW+0+
tdtFXij/jtxAyabTLNTivAXO44l6IBurtlAZqXeI1ur6gEJa0L1Ju0Mi6rFO/Vrg
aQ/KBo+1DM4QgXxYkcYPxJ+KIJKQdsmIWEmpni+sgaLBgO43Ebh+lkLKHCm5NB0l
kaIgld2V1OQQDmg/j4yW
=Tegq
-----END PGP SIGNATURE-----