[syslinux] Boot time arguments

[ganapathy murali krishnan]

> label prep
>      kernel gmklinux
>      append root=/dev/ram0 initrd=rootfs.img image=fdisk mountcd=no \
>                  network=dhcp logfile=/dev/tty4 utils=utils 
> baseurl=http://sysconf/gui
>
> If I type "prep mountcd=yes" at the boot prompt. The boot time 
> arguments I supply does not seem to
> take effect. Once I boot into the kernel, inspection of 
> /proc/1/environ reveals "mountcd=no". I am not using
> any global appends. On the other hand, if I type "gmklinux 
> root=/dev/ram0 ... mountcd=no ... mountcd=yes..."
> on the command line and once I boot into the kernel, /proc/1/environ 
> has both the mountcd options, but
> the second one overrides the first (echo $mountcd returns yes).
>
After a little more experimenting I found the following:
1. In all cases /proc/1/cmdline has "init"
2. If the append line has length < 128 chars, then any thing I type at 
the boot prompt seems to work.
3. If the append line has length > 128 chars, then whatever I type at 
the boot prompt doesn't seem
   to be passed to the kernel.
I am not sure about the 128, it is somewhere between 120 and 135. On the 
other hand the linux kernel
can take a 255 char command line right? Is that changeable?

- Murali