I have a laptop running Oracle Solaris and Gentoo Linux.First I installed Gentoo Linux. I used GPT partitioning scheme. In order to boot Gentoo Linux I have GRUB 2.Then I installed Solaris 11.1. Now GRUB from Solaris overwrote the GRUB from Gentoo Linux and it didn't detect it and so currently I have only Solaris in the boot menu.What I would like to do is to modify Solaris' GRUB configuration in order to do a dual boot by chainloading, since Solaris' GRUB does not support ext2 file system.Unfortunately Solaris documentation about GRUB, which is here, does not give an example about Linux - it's Windows only.So I created /rpool/boot/grub/custom.cfg:root@solaris:/rpool/boot/grub# cat custom.cfgmenuitem Gentoo {    insmod gpt_part    insmod chain    set root=(hd0,ext2)    chainload --force +1}and then rebooted.When GRUB started, I saw only Solaris menu.Do I have to run some additional commands on Gentoo Linux, in order for the GRUB configuration to take effect?On Solaris, I didn't see anything like this in the docs.What am I missing? At least the menuitem Gentoo should be visible in the GRUB.GRUB configuration /rpool/boot/grub/grub.cfg:igor@solaris:~/Broadcom$ cat /rpool/boot/grub/grub.cfg## DO NOT EDIT THIS FILE## It is automatically generated by grub-mkconfig using templates# from /usr/lib/grub2/bios/etc/grub.d and settings from /usr/lib/grub2/bios/etc/default/grub#### BEGIN /usr/lib/grub2/bios/etc/grub.d/00_header ###if [ -s $prefix/grubenv ]; then  load_envfiset default=0if [ ${prev_saved_entry} ]; then  set saved_entry=${prev_saved_entry}  save_env saved_entry  set prev_saved_entry=  save_env prev_saved_entry  set boot_once=truefifunction savedefault {  if [ -z ${boot_once} ]; then    saved_entry=${chosen}    save_env saved_entry  fi}function load_video {  insmod vbe}if loadfont /@/boot/grub/unicode.pf2 ; then  set gfxmode=1024x768x32;1024x768x16;800x600x16;640x480x16;640x480x15;640x480x32  load_video  insmod gfxterm  set locale_dir=($root)${prefix}/locale  set lang=en_US  insmod gettextfiterminal_output gfxterminsmod part_gptinsmod zfsset root=''if [ x$feature_platform_search_hint = xy ]; then  search --no-floppy --fs-uuid --set=root  e71191bc1127be5celse  search --no-floppy --fs-uuid --set=root e71191bc1127be5cfiinsmod gfxmenuloadfont ($root)//@/boot/grub/themes/solaris/liber18.pf2loadfont ($root)//@/boot/grub/themes/solaris/univers16.pf2loadfont ($root)//@/boot/grub/themes/solaris/univers20.pf2insmod jpeginsmod pngset theme=($root)//@/boot/grub/themes/solaris/theme.txtset timeout=30### END /usr/lib/grub2/bios/etc/grub.d/00_header ###### BEGIN /usr/lib/grub2/bios/etc/grub.d/10_solaris ###menuentry Oracle Solaris 11.1 {    insmod part_msdos    insmod part_sunpc    insmod part_gpt    insmod zfs    search --no-floppy --fs-uuid --set=root e71191bc1127be5c    zfs-bootfs /ROOT/solaris/@/ zfs_bootfs    set kern=/platform/i86pc/kernel/amd64/unix    echo -n Loading ${root}/ROOT/solaris/@$kern:     $multiboot /ROOT/solaris/@/$kern $kern -B console=graphics -B $zfs_bootfs    set gfxpayload=1024x768x32;1024x768x16;800x600x16;640x480x16;640x480x15;640x480x32    insmod gzio    echo -n Loading ${root}/ROOT/solaris/@/platform/i86pc/amd64/boot_archive:     $module /ROOT/solaris/@/platform/i86pc/amd64/boot_archive}if [ $target = i386_pc ]; then    search --no-floppy --fs-uuid --set=root_rpool e71191bc1127be5c    if [ -s ($root_rpool)/@/boot/grub/menu.lst ]; then        submenu Legacy GRUB Menu (from root pool rpool) ($root_rpool)/@/boot/grub/menu.lst {            extract_legacy_entries_source $2        }    fifi### END /usr/lib/grub2/bios/etc/grub.d/10_solaris ###### BEGIN /usr/lib/grub2/bios/etc/grub.d/41_custom ###if [ -f  $prefix/custom.cfg ]; then  source $prefix/custom.cfg;fi### END /usr/lib/grub2/bios/etc/grub.d/41_custom ###
Dual boot Solaris and Linux
linux;solaris;grub2;dual boot