kexec_load

load a new kernel for later execution

sys_kexec_load(unsigned long entry, unsigned long nr_segments, struct kexec_segment *segments, unsigned long flags)

register	value
`r3`	283, the syscall number
`r4`	unsigned long entry
`r5`	unsigned long nr_segments
`r6`	struct kexec_segment *segments
`r7`	unsigned long flags
`r0`	the return value

Then run trapa #31 to enter the kernel.

Same syscall on other architectures