[syslinux] Some patches from mageia

[Sebastian Herbszt]

Gene Cumm wrote:
> On Sat, Dec 12, 2015 at 8:21 AM, Ady via Syslinux <syslinux at zytor.com> wrote:
> >
> >> On Thu, Dec 10, 2015 at 5:15 PM, Sebastian Herbszt <herbszt at gmx.de> wrote:
> >> > Gene Cumm wrote:
> >> >> On Tue, Dec 1, 2015 at 3:02 PM, Erwan Velu via Syslinux
> >> >> <syslinux at zytor.com> wrote:
> >> >> > Hi folks,
> >> >> >
> >> >> > As per Ady request (thanks for the reminder), I forgot to send the patches
> >> >> > I run in Mageia.
> >> >> >
> >> >> > There is two of them :
> >> >> >
> >> >> > One is making errors in parsing modules.alias not fatal.
> >> >> >
> >> >> > The other one is adding an option to chain to avoid reading garbage on the
> >> >> > command line.
> >> >> > I had some issues with gfxboot and had to implement that. I know it's a
> >> >> > workaround, I don't really get if that's useful for others. You can forget
> >> >> > it if you consider it as too weird.
> >> >>
> >> >> This almost sounds like a global APPEND was used.  Current Syslinux
> >> >> should ignore the global APPEND for COM32 use but other config parsers
> >> >> like (vesa)menu.c32 and gfxboot.c32 might not as they don't call by
> >> >> LABEL but execute plain commands.
> >> >
> >> > How can I reproduce this issue?
> >> >
> >> > Sebastian
> >>
> >> http://rpmfind.net/linux/mageia/distrib/cauldron/i586/isolinux/isolinux.cfg
> >> and http://rpmfind.net/linux/mageia/distrib/cauldron/x86_64/isolinux/isolinux.cfg
> >> ( http://distro.ibiblio.org/mageia/distrib/cauldron/ appears to be
> >> another mirror) look clean from anything that should resemble a global
> >> APPEND.
> >>
> >> Using the files from the above directory, I see
> >> "automatic=method:cdrom" appended as an extra argument.  Trimming
> >> unnecessary files, I can get it to an ISO under 1 MiB (trim hdt.c32,
> >> memtest, modules.*, *.ids, *.hlp ).
> >>
> >> --
> >> -Gene
> >
> > FWIW, kernel.org also has mirror(s) for mageia (including these
> > directories / files).
> >
> > IIRC, the issue is not related to any global APPEND (mageia does not
> > use it), but to the interaction between gfxboot.c32 and chain.c32.
> >
> > To replicate, see "gfxboot.cfg" and "isolinux.cfg" for mageia (in the
> > aforementioned directories)
> >
> > Relevant lines in these 2 cfg files:
> > ["gfxboot.cfg"]
> > ; main menu items where user can't add boot options
> > nobootoptions=harddisk,memtest
> > ; main menu items that are not passed an 'install' parameter
> > noinstallopt=harddisk,firmware,memtest
> > [/"gfxboot.cfg"]
> >
> > ["isolinux.cfg"]
> > ui gfxboot.c32 bootlogo
> > label harddisk
> >   com32 chain.c32 hd0 exit
> > [/"isolinux.cfg"]
> >
> > As usual, using 3 or more menu entries is recommended so to avoid the
> > minor "quirks" when using less than that amount. Please don't forget to
> > use unique LABELs without special characters (such as spaces).
> >
> > Alternatives for potential testing, either with the original Syslinux
> > 6.03, or with later development code before the introduction of the
> > "exit" hack:
> > ["isolinux.cfg"]
> > ui gfxboot.c32 bootlogo
> > label harddisk
> >   com32 chain.c32 hd0
> >   # no "exit"
> > [/"isolinux.cfg"]
> >
> > ["isolinux.cfg"]
> > ui gfxboot.c32 bootlogo
> > label harddisk
> >   com32 chain.c32
> >   append hd0 exit
> >   # using "append"
> > [/"isolinux.cfg"]
> >
> > ["isolinux.cfg"]
> > ui gfxboot.c32 bootlogo
> > label harddisk
> >   com32 chain.c32
> >   append hd0
> >   # using "append" but no "exit"
> > [/"isolinux.cfg"]
> >
> > ["isolinux.cfg"]
> > ui gfxboot.c32 bootlogo
> > label harddisk
> >   com32 chain.c32
> >   # using no parameter at all, thus using the default
> > [/"isolinux.cfg"]
> >
> > Additional alternative testing:
> >
> > From the gfxboot screen, exit to the "normal" Syslinux boot prompt and:
> > _ type in "harddisk" (thus, using the label from isolinux.cfg); and/or,
> > _ type in the command, "chain.c32 hd0".
> >
> > The last 2 alternative tests should allow to get the expected result
> > without the interference of gfxboot. This is usually not what is wanted
> > for final users to use; this is just a workaround, and a method to test
> > the interaction with gfxboot.
> 
> I'm going to guess it's related to bootlogo since the string is found
> at offset 0x12387.

"automatic=method:cdrom" seems to come from "install.set.install.option"
whose source is in src/dia_install.inc which is available in the theme
source [1].

[1] http://mirrors.kernel.org/mageia/distrib/cauldron/SRPMS/core/release/mageia-gfxboot-theme-4.5.6.9-1.mga6.src.rpm

Sebastian