Re: installation-guide: document max. length of boot parameters
Hi,
russm <russm-debian-bugs@slofith.org> wrote:
> Hi Holger,
>
> Thanks for picking up this long-stale bug :)
>
> It looks like sometime in the intervening 10 years this restriction has
> been fixed, or perhaps just lengthened, but I just booted a live CD with
> GRUB and a 260 character kernel command line and it was *not* truncated.
>
> Rather than quoting a specific 255-character limit, perhaps just mention
> that particularly long kernel command lines may be silently truncated?
Hmm, I it found documented, that there *is* a limit of 255 characters for the
*kernel*, but the bootloader *may* allow to exceed this.
As that means, it depends on which bootloader is used, if the limit is at
255 or more, I think it is best to mention this limit of 255 chars, but
I will relativise it a bit:
<quote>
Also there is a limit of 255 characters for the whole kernel command line,
everything above this limit may be silently truncated.
</quote>
(note the "may" :-) )
Holger
>
> cheers
>
> Russell
>
>
> On Mon, Jul 03, 2017 at 06:25:20AM +0200, Holger Wansing wrote:
> > Control: tags -1 + pending
> >
> >
> > russell muetzelfeldt <russm-debian-bugs@slofith.org> suggested:
> > > Package: debian-installer-manual
> > >
> > > Section B.2.2 (Using boot parameters to supplement preseeding) notes
> > > that current kernels can accept a maximum of 32 command line options,
> > > but says nothing about a maximum number of characters on the kernel
> > > command line.
> > >
> > > There appears to be a 255 character maximum for parameters, after
> > > which the kernel command line is silently truncated. I have no idea
> > > if this is a limitation of the kernel, or of grub, but it should
> > > probably be noted along with the 32 parameter limit.
> >
> > Fixed in svn.
> >
> >
> > Holger
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