Re: bzImage ~ 900K with i386 test11-pre2

Eric W. Biederman
2000-11-12T19:28:50Z

Andrea Arcangeli <andrea@suse.de> writes:

> On Sun, Nov 12, 2000 at 06:14:36AM -0700, Eric W. Biederman wrote:
> > x86-64 doesn't load the segment registers at all before use.
>
> Yes, before switching to 64bit long mode we never do any data access. We do a
> stack access to clear eflags only while we still run in legacy mode with paging
> disabled and so we only rely on ss to be valid when the bootloader jumps at
> 0x100000 for executing the head.S code (and not anymore on the gdt_48 layout).

Actually it just occurred to me that this stack assess is buggy. You haven't
set up a stack yet so. Only the boot/compressed/head.S did and that location isn't
safe to use.

Eric