On 5/15/26 18:21, Tom Rini wrote:
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
I expected this to grow due to reordering
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
But I thought the nvedit stuff would result in a size reduction. There are 4-5
options
for each command, so the env stuff is basically a best-case scenario. Maybe we
need to revisit the getopt interface.
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.
