On Thu, Mar 07, 2002 at 10:08:19PM +0600, Anuradha Weeraman wrote: > As I was reading the bootstrap code (bootsect.S), I came across : > movw $BOOTSEG, %ax > movw %ax, %ds # %ds = BOOTSEG > movw $INITSEG, %ax > > $BOOTSEG gets assigned to %ax which gets assigned to %ds. I am also new > to assembly, but could the first two lines be made into a single line like > movw $BOOTSEG, %ds > > Is this possible? or is there a reason for it going through %ax, which > appears to be a redundant middle-man since its immediately overwritten > in the third line. > movw $INITSEG, %ax move immediate to segment register is not supported in Intel. i.e., you can't move an immediate value directly to a segment register. Hence here, immediate value BOOTSEG is moved to %ax(a general purpose register) first and then from %ax to %ds. Regards, Bharata. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
