Menu
▾
▴
#98 patch to allow specific NetBoot server
Is it possible for me to hack the current rEFIt (0,14) to allow for the possibility to use a specific NetBoot server? Or would that require me to patch the source code?
I'd like to put rEFIt inside the Lion Recovery HD partition so it can be accessed using CMD-R and be presented with a choice to NetBoot a specific server. This server is not accessible directly at my site due to netboot-across-subnet issues; the IPhelpers won't be modified. I can issue a bless --netboot --server bsdp://123.123.123.123 --nextonly command manually but I'd like something a bit more technician-friendly ;-)
You would need to modify the source code.
First you need to figure out how to netboot from an EFI program. The source code for the bless command might help with that. You can look at the rEFIt code to see how it boots BIOS using the same info that bless modifies. I guess netboot would be similar to that. Use the Startup Disk preferences panel or the bless command to set Legacy (BIOS), or Mac OS, or Network Startup as the boot device. Then use the following command:
ioreg -w 0 -n AppleEFINVRAM | sed -n -E "/^[ \|]+[ ]+(\".*)$/s//\1/p;"
and examine the "efi-boot-device" NVRAM variable which is the XML representation of the "efi-boot-device-data" NVRAM variable used by EFI. The variable contains the EFI device path of the Legacy loader when you have a Windows partition selected. I guess it would contain the EFI device path for netboot when you have Network startup selected.
Then, you need to be able to add NetBoot servers to the refit.conf file and have rEFIt parse them and add them to the boot list.
Being able to put rEFIt on the Recovery HD so it can be accessed using CMD-R is optional. You would need to figure out how CMD-R works. Do you have to rename/move rEFIt so that it takes the place of an existing EFI app on the Lion or Recovery HD partition or can you change what EFI program CMD-R uses?