[RFC PATCH 00/11] Tidy command option parsing and use it a bit

[Tom Rini]

On Fri, May 15, 2026 at 06:06:38PM -0400, Sean Anderson wrote:
> On 5/15/26 17:59, Sean Anderson wrote:
> > On 5/15/26 17:43, Tom Rini wrote:
> > > On Fri, May 15, 2026 at 02:32:51PM -0600, Simon Glass wrote:
> > > 
> > > > We have had getopt() for over five years but it is not much used. It is
> > > > much easier to understand arg-parsing using getopt() and it avoids
> > > > common errors. As the named maintainer I decided to look at how to make
> > > > more use of it.
> > > > 
> > > > So this series explores the impact of converting a few commands to use
> > > > getopt() instead of ad-hoc parsing. It updates getopt() to handle flags
> > > > anywhere in the cmdline and provides a few helpers to reduce
> > > > boilerplate.
> > > > 
> > > > The chosen commands are:
> > > > 
> > > > - echo: very simple with no flags
> > > > - hash: fairly simple with just one flag
> > > > - env grep/export/import - fuller examples
> > > > 
> > > > The series also adds a recommendation to use getopt() for new commands.
> > > > 
> > > > To try to reduce the code-size increase, a lower-case function is added
> > > > and called from a few places. The difference is fairly marginal.
> > > > 
> > > > Overall, the result is not pretty (see below) with about a 1.1K size
> > > > increase on arm64:
> > > 
> > > I think that means this is a no-go, and you need to work out what might
> > > lead to a much smaller growth here.
> > > 
> > 
> > Unfortunately, the only way to get a size reduction is to convert as many
> > commands as possible.
> > 
> > --Sean
> 
> And to expand on this, you really only get a reduction for any given command
> when there are several options being parsed already like in the nvedit stuff.
> Since most U-Boot commands don't use options it will be difficult to get a
> reduction even when converting most commands on a board.

We don't even see a reduction on "qcom" which is a platform that already
enabled GETOPT. nvedit is growth too:
01: Prepare v2026.07-rc2
02: lib: string: Add strlower()
   aarch64: (for 1/1 boards) data -40.0 rodata +40.0
            qcom           : data -40 rodata +40
03: cmd: ini: Use strlower() to normalise case
04: fs: fat: Use strlower() to normalise case
05: boot: pxe_utils: Use strlower() in get_string()
06: lib: getopt: Permute by default with inline reorder
   aarch64: (for 1/1 boards) all -6.0 data -24.0 rodata +18.0
            qcom           : all -6 data -24 rodata +18
               u-boot: add: 0/0, grow: 5/-1 bytes: 272/-8 (264)
                 function                                   old     new   delta
                 __getopt                                   576     756    +180
                 getopt_init_state                           12      88     +76
                 do_log_filter_remove                       364     372      +8
                 do_log_filter_list                         444     448      +4
                 do_log_filter_add                          580     584      +4
                 do_bdinfo                                  160     152      -8
07: lib: getopt: Add getopt_pop() helper
08: cmd: echo: Use getopt() with '+' prefix for option parsing
   aarch64: (for 1/1 boards) all +3.0 rodata +3.0
            qcom           : all +3 rodata +3
               u-boot: add: 0/0, grow: 1/0 bytes: 68/0 (68)
                 function                                   old     new   delta
                 do_echo                                    156     224     +68
09: cmd: hash: Use getopt() for option parsing
10: cmd: nvedit: Use getopt() in env grep
11: cmd: nvedit: Use getopt() in env export and env import
   aarch64: (for 1/1 boards) all -4.0 data -16.0 rodata +12.0
            qcom           : all -4 data -16 rodata +12
               u-boot: add: 0/0, grow: 2/0 bytes: 164/0 (164)
                 function                                   old     new   delta
                 do_env_import                              692     832    +140
                 do_env_export                              608     632     +24
12: doc: commands: Recommend getopt() for option parsing

> That's why I used it for new commands where no one could complain that
> I grew their board.
> 
> I think it would be nice for all u-boot commands to have proper option support
> like in barebox, but it's a lot of effort.

Yes, it would be good to move in that direction. But we need to figure
out how to do it in such a way that's not such a big size loss. If we
have to do a big conversion to start with, fine. If we have to
restructure a few other things, fine. But "convert echo so everyone
links it now and it's sunk-cost" isn't the right path.

-- 
Tom
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