[U-Boot] a couple questions about CONFIG_SYS_LONGHELP

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Robert,

On Sat, 26 Jan 2013 06:38:51 -0500 (EST), "Robert P. J. Day"
<rpjday@crashcourse.ca> wrote:

> 
>   first, is there any need for so many header files to define the
> macro CONFIG_SYS_LONGHELP individually?  a quick count of how many
> u-boot source files do just that:
> 
> $ grep -r "define.*CONFIG_SYS_LONGHELP" * | wc -l
> 479
> $
> 
> is it really necessary for almost 500 source files to each define that
> macro?

Yes, is is, because each target should decide individually if they want
to embed the long help, which costs space and time, two valuable
resources in embedded development.

>   and second, i'm not sure how to read this out of cmd_pci.c:
> 
> ===== start
> 
> #ifdef CONFIG_SYS_LONGHELP
> static char pci_help_text[] =
>         "[bus] [long]\n"
>         "    - short or long list of PCI devices on bus 'bus'\n"
> #ifdef CONFIG_CMD_PCI_ENUM
>         "pci enum\n"
>         "    - re-enumerate PCI buses\n"
> #endif
>         "pci header b.d.f\n"
>         "    - show header of PCI device 'bus.device.function'\n"
>         "pci display[.b, .w, .l] b.d.f [address] [# of objects]\n"
>         "    - display PCI configuration space (CFG)\n"
>         "pci next[.b, .w, .l] b.d.f address\n"
>         "    - modify, read and keep CFG address\n"
>         "pci modify[.b, .w, .l] b.d.f address\n"
>         "    -  modify, auto increment CFG address\n"
>         "pci write[.b, .w, .l] b.d.f address value\n"
>         "    - write to CFG address";
> #endif
> 
> U_BOOT_CMD(
>         pci,    5,      1,      do_pci,
>         "list and access PCI Configuration Space", pci_help_text
> );
> 
> ===== end
> 
>   note how, if CONFIG_SYS_LONGHELP is defined, the symbol
> "pci_help_text" is created as the text, but its *usage* just below in
> the U_BOOT_CMD macro is *outside* of that preprocessor check.  how
> would that work if CONFIG_SYS_LONGHELP is undefined?  not at my dev
> host right this minute so i can't test, but it just looks ... weird.

Probably would not work. Submit a fix. :)

> rday

Amicalement,
-- 
Albert.