[U-Boot] [PATCH] pxe: Allow use of environment variables in append string

Stephen Warren
2014-08-01T19:07:24Z

On 08/01/2014 03:21 AM, Hans de Goede wrote:
> Use run_command("setenv bootargs <label->append>") so that environment
> variables (e.g. $console) can be used in append strings.

I'm slightly worried that this changes the semantics of the append line
in the PXE/extlinux config file. Namely, you suddenly have to start
worrying about escaping any $ signs or semi-colons etc..

> diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c

> if (!localcmd)
> return -ENOENT;
>
> - if (label->append)
> - setenv("bootargs", label->append);
> + if (label->append) {
> + bootargs = malloc(strlen("setenv bootargs ") +
> + strlen(label->append) + 1);
> + if (!bootargs)
> + return 1;

Shouldn't this return a -ve error code for consistency with the other
pre-existing error case I quoted above.

> + strcpy(bootargs, "setenv bootargs ");
> + strcat(bootargs, label->append);
> + run_command(bootargs, 0);

Using whatever C function that the shell uses to expand variable
references in the command-line, rather than run_command(), would at
least avoid the issue of ; in label->append causing part of
label->append after the ; to be execututed as a separate command.

There would still be the issue of $ suddenly meaning something different.