I believe they said that the code for the easter egg that starts sshd is in their modified version of flash (i.e., you won't be able to find it by searching the code). So we'll just have to keep trying things on the chumby.
I'm still trying to make progress on running sshd from a chumbydebug script, but I haven't had any luck yet. I tried using an ext2fs formatted drive, which I saw suggested somewhere, but that didn't seem to help.
I'm not sure if the ".config" file in the distributed kernel-src.tar.gz is accurate/up-to-date, but if it is, then it appears that EXT2FS support isn't even compiled:
[~/chumby_kernel]$ grep EXT2 .config
# CONFIG_EXT2_FS is not set
File systems that *do* appear to have support compiled:
[~/chumby_kernel]$ grep _FS=y .config
CONFIG_FAT_FS=y
CONFIG_MSDOS_FS=y
CONFIG_UMSDOS_FS=y
CONFIG_VFAT_FS=y
CONFIG_JFFS2_FS=y
CONFIG_PROC_FS=y
CONFIG_DEVFS_FS=y
CONFIG_ROMFS_FS=y
CONFIG_NFS_FS=y
If anyone with a foo-camp chumby does manage to get sshd running via a usb chumbydebug script, please post a detailed description of how you did it to the wiki.