[syslinux] Booting second label

Gene Cumm gene.cumm at gmail.com
Tue Aug 13 04:12:09 PDT 2013

On Tue, Aug 13, 2013 at 3:21 AM, Bjørn Damstedt Rasmussen
<bjra at terma.com> wrote:
> Hi
> I'm using syslinux 5.01 and is installing our bootloader using "extlinux --install /boot". In the extlinux.conf I've specified that the kontron_wdt.c32 program should boot another label once it has been executed but it never calls the second label.

Did you build all of the COM32s and extlinux?  Do you ever see an error?

> Here's my extlinux.conf:
> default wdt
> timeout 5
> prompt 1
> label linuxfoo
> kernel /vmlinuz
> append root=/dev/sda2 #.... more options
> label wdt
> com32 kontron_wdt.c32
> append timeout=120 default_label= linuxfoo
> When I try to debug the kontron_wdt.c32 I can see that syslinux_run_command(..) returns -1. What could cause this?

What string would the above config pass to syslinux_run_command()?
Does it have a trailing line end character?  terminating NUL

> I've tried the ifcpu.c32 application as well (which is a bit similar to kontron_wdt.c32) and it also cannot call syslinux_run_command().
> I can see that syslinux_run_command() call create_args_and_load() but if I put any printf's there they're not printed to screen, so it's pretty hard to debug what's causing the error.

Are you using printf() or dprintf()?

> If someone knows a way to call two labels that would also work as a workaround for the problem I'm trying to solve.

Are you just looking to append additional parameters to another LABEL?
 Try this:

COM32 cmd.c32
APPEND linuxfoo timeout=120


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