Sometimes I'm a bit slow. Sometimes I'm a bit stubborn. Sometimes I don't read. Sometimes I read but fail to comprehend. Fortunately, naturally occurring ignorance has a cure --- a willingness to learn.
The problem was not the 4GB barrier. That was only some kind of weird coincidence. The problem was between the keyboard and chair --- a lack of knowledge. Unknown to me, running 'make clean' or 'make mrproper' after building my kernel and then someday later trying to build VirtualBox caused the problem. The trick is to build the kernel and not run 'make clean' or 'make mrproper', or as zhoun mentioned previously (drum roll), run 'make prepare'.
Well, I spent many hours yesterday testing all of this. Compiling a kernel takes time. Building VirtualBox takes time. Several hours go by trying different variables and options. Eventually the eyeballs turn square.
Finally I convinced myself that all I needed was to run 'make prepare' in the kernel build directory before running the VirtualBox build script. No changes to the kernel >4GB RAM option, no need to change the kernel .config file.
I made two passes at building both VirtualBox 1.6.6 and 2.0.6 in 12.2 with the 184.108.40.206 kernel configured for >4GB RAM. No hitches.
If I run 'make clean' in the kernel build directory the VirtualBox build script fails rather quickly.
I never had run into this problem before. I guess I was just lucky to never have run 'make clean' or 'make mrproper' before building VirtualBox.
Not to mention the mystery of why VirtualBox would
compile when I modified the RAM option in the kernel.
Sometimes learning a lesson takes all day and then some. I don't fully understand all the connections with the command, but I think I now grasp the big picture. I think the words 'make prepare' will be stamped in my mind for a few days.
As the old Groucho Marx joke goes, "Don't do that anymore!"
I am willing to embrace my own lack of knowledge as the cornerstone of the problem here. Conversely, I never had this problem with previous kernels. Seems the 220.127.116.11 kernel or something related is now different.
Perhaps previously the 'make clean' or 'make mrproper' commands did not remove certain critical files that other software needed to build and now with 18.104.22.168 that is the case. I say this because I had a similar problem with updating the 177.82 nvidia driver and kernel module. Another person had a similar problem
with the nvidia driver and the 'make prepare' trick resolved the problem.
Still, if we keep our eyes and ears open we usually learn something every day.
Folks sometimes ask me what I do for recreation. I tell them sometimes I sit on the front porch. And do what? they ask. I tell them sometimes I sit and think, sometimes I just sit.
My head hurts and my butt is numb. Or is that my butt hurts and my head is numb? I don't know. After this experience I think I'll just sit for a bit. No thinking.