(good to see some familiar and friendly faces from the PPC list! :-)
I ran into a problem yesterday and I just don't know how I'm going to
approach solving it.
I compiled a 64-bit MIPS kernel, then built a busybox-based ramdisk. At
first I couldn't get busybox's 'init' to work but later solved it by
disabling the 'check_memory()' call.
Further investigation into why the 'check_memory()' call was failing
revealed a problem with the 'sysinfo()' system call. The kernel is
64-bit, therefore when it fills in the 'struct sysinfo' (as it does
when 'sys_meminfo()' is called) unsigned int's are 64 bits. But back in
userspace, the 'struct sysinfo' that gets allocated thinks that
unsigned int's are 32 bits.
This causes a crash if the 'struct sysinfo' is allocated on the stack
back in userspace, and causes seg faults if it's allocated in the .data
I'm crossing my fingers and hoping that my solution is to build all
user-space apps with some switch that will set the sizes of data types
to be the same between user space and kernel space. Does some such