Grub2 Debian Squeeze "Multiple entries for serial support patch"
23 Feb 2010 - Francesco `ascii` Ongaro - ascii@ush.it

Your feedback for Debian Squeeze is appreciated!

By the way you need a Grub2 version with this bug fixed: 
http://savannah.gnu.org/bugs/?28628

Don't forget to run update-grub at the end.

$ diff etc_grub.d_10_linux.orig etc_grub.d_10_linux
58c58
<   recovery="$3"
---
>   mode="$3"
60,61c60,65
<   if ${recovery} ; then
<     title="$(gettext_quoted "%s, with Linux %s (recovery mode)")"
---
>   if [ ${mode} -eq 1 ]; then
>     title="$(gettext_quoted "%s, with Linux %s (recovery)")"
>   elif [ ${mode} -eq 2 ]; then
>     title="$(gettext_quoted "%s, with Linux %s (serial)")"
>   elif [ ${mode} -eq 3 ]; then
>     title="$(gettext_quoted "%s, with Linux %s (both)")"
129c133
<   linux_entry "${OS}" "${version}" false \
---
>   linux_entry "${OS}" "${version}" 0 \
130a135
> 
132c137
<     linux_entry "${OS}" "${version}" true \
---
>     linux_entry "${OS}" "${version}" 1 \
135a141,150
>   if [ "x${GRUB_DISABLE_LINUX_SERIAL}" != "xtrue" ]; then
>     linux_entry "${OS}" "${version}" 2 \
>       "${GRUB_CMDLINE_LINUX_SERIAL}"
>   fi
> 
>   if [ "x${GRUB_DISABLE_LINUX_BOTH}" != "xtrue" ]; then
>     linux_entry "${OS}" "${version}" 3 \
>       "${GRUB_CMDLINE_LINUX_BOTH}"
>   fi
> 

$ diff usr_sbin_grub-mkconfig.orig usr_sbin_grub-mkconfig
260a261,262
>   GRUB_CMDLINE_LINUX_SERIAL \
>   GRUB_CMDLINE_LINUX_BOTH \

$ diff etc_default_grub.orig etc_default_grub
7c7,9
< GRUB_CMDLINE_LINUX_DEFAULT="quiet"
---
> GRUB_CMDLINE_LINUX_DEFAULT="console=tty0"
> GRUB_CMDLINE_LINUX_SERIAL="console=ttyS0,115200"
> GRUB_CMDLINE_LINUX_BOTH="console=tty0 console=ttyS0,115200"
16c18,19
< #GRUB_TERMINAL=console
---
> GRUB_TERMINAL=console
> GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
27a31,32
> #GRUB_DISABLE_LINUX_SERIAL="true"
> #GRUB_DISABLE_LINUX_BOTH="true"