On Thu, Aug 11, 2011 at 09:53:10PM +0700, Mulyadi Santosa wrote: > On Thu, Aug 11, 2011 at 18:18, jiangtao.jit <jiangtao.jit@xxxxxxxxx> wrote: > > Hi all: > > > > on booting of x86 > > top of file arch/x86/boot/pmjump.S > > there is code > > ------------------- > > GLOBAL(protected_mode_jump) > > movl %edx, %esi > > xorl %ebx, %ebx > > i think it's zeroing bx (l--> low I suppose) Long, actually, i.e. 32-bit. > > > movw %cs, %bx > > then, it should zero the content of cs. Quite likely, it means to jump > to cpu ring level 0 and do something there.. No, this is written in AT&T syntax, where the source comes first, and then the destination. IOW, the code means: Copy the 16 bit register CS into the lower 16 bit of EBX (which is BX). CMIIW, Jonathan Neuschäfer _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
