Re: [PATCH] bootup: Add built-in kernel command line for x86

Ingo Molnar
2008-08-11T19:10:41Z

* Tim Bird <tim.bird@am.sony.com> wrote:

> Add support for a built-in command line for x86 architectures. The
> Kconfig help gives the major rationale for this addition.

i have actually used a local hack quite similar to this to inject boot
options into bzImages via randconfig - so i would find this feature
rather useful.

a small observation:

> + /* append boot loader cmdline to builtin, unless builtin overrides it */
> + if (builtin_cmdline[0] != '!') {
> + strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
> + strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
> + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
> + } else {
> + strlcpy(boot_command_line, &builtin_cmdline[1],
> + COMMAND_LINE_SIZE);
> + }

the default branch changes existing command lines slightly: it appends a
space to them. This could break scripts that rely on the precise
contents of /proc/cmdline output. (i have some - they are arguably
dodgy)

Best would be to make it really apparent in the code that nothing
changes if this config option is not set. Preferably there should be no
extra code at all in that case.

Ingo