Is there any particular reason why the misc devices are used instead of cdev?
I wanted to get rid of the static major/minor number assignment, and was under the false impression that cdev cannot allocate new numbers automatically. In addition (and more importantly), I wanted the kernel to create device files in /dev automatically (via devtmpfs), and I did not know how that can be done with cdev-s. Miscdevices provided both features, so I used them instead.
another thing is that I am getting error when trying to compile the Linux in sccmem.c
In function 'rckdyn_write'
" error: '__PHYSICAL_START' undeclared (first use in this function) "
There once was a definition for this symbol, but I cannot find it in the current sources anymore. You can try using the definition from arch/x86/include/asm/page_64_types.h (copy the #define to your modified sccmem.c instead of including that file directly).