The Macosx side looks ok thanks. Just making sure about EFI upper case, I assume you are seeing the grub menu now.
Originally Posted by gcarlsen
I think you may have a bug with your usb linux install. (Got to blame something).
I am using MacBook2,1 with Xubuntu 810 intrepid desktop install here, with 2.6.27 i386 kernel, installed on an 8GB usb flash stick, partitioned by MacOSX with GUID partitioning option. You have msdos partitoning, but that should not prevent the kernel and initrd starting up and I will check here to confirm that.
I have also made a small hfsplus partition on the usb to install grubefi where it is blessed so can run without refit, but that is not your problem just now.
Can you look at the usb system with a live cd, and check the kernel version in the /boot directory, or get a file listing for the root partition, and for /boot.
If you have the grub menu now, you should start a second grub.cfg version with your edited entries for the record and to avoid having to use the grub> command line.
Note that the chainloader command for macosx does not work for me at the grub> command line, but does work perfectly when run as a menuentry. (but there is no such problem for linux loading).
You cannot see /dev/sd* in the usb root system because the device node does not exist until the initialization, also you can boot the kernel and run the initramfs with no kernel arg for 'root=/dev/sdx' at all , that will get as far as (initramfs) busybox for debugging, enough to prove its starting up.
This is what I see for a successful startup from grub> commandline - (I ran it with no kernel arg for root=/dev/sdX). I assume you got all this as far as the grub> boot, but could you confirm that .
Did you get this far with all the messages similar to the above
grub> search --set /vmlinuz
grub> linux /vmlinuz video=efifb
[Linux-bzimage, setup=0x3000, size=0x220cb0]
Video frame buffer:40000000
grub> initrd /initrd.img
[Initrd, addr=0x3a914000, sie=0x7cc3ab1]
Was there anything more? (give it 5 minutes in case there is a hangup somewhere)