Ok, so very simply, I am manually remastering Core on Xubuntu 12.04 (LTS) by adding some persistent binaries that I need using these commands:
Extracting core.gz: zcat core.gz | sudo cpio -i -H newc -d
Then I add some binaries in /usr and package it back up using this:
Packaging core.gz: sudo find | sudo cpio -o -H newc | gzip > ../core.gz
This does NOT work. When I boot up the remastered core.gz now, the system prints out a stacktrace followed by the message "Fixing recursive fault but reboot is needed!" If the kernel is printing this out, it should not, because I did not touch vmlinuz. If I download core.gz from the website, it works just fine, so extracting it or packaging it up must be causing an issue somewhere. I used to use the same procedure in 3.x and it always worked fine, but it doesn't seem to be working in Core 4.7. Is it possible that a new version of cpio or gzip/gunzip is causing errors (I used to be on Xubuntu 11.04 which probably used older packages)? Did something else change in the core structure? Thanks. I don't want to use any of the remaster extensions because we will need a build script to automate this procedure eventually, and this is the easiest way. I guess the next logical thing to try is to use an older environment to remaster this in, like the 11.04 I was using before.
Thought I'd point this out too: I get the same exact error message printed when I try to upgrade the kernel to 3.0.50. I compile the kernel just fine and it works fine. But when I get to modifying the core.gz structure to point to 3.0.50 folders now instead of the 3.0.21 ones and packaging it back up, I get the same error on startup.