Messages in this thread | | | Date | Sun, 4 Nov 2007 16:23:11 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [PATCH] fix i486 boot failure due to stale %ds |
| |
On Sun, 4 Nov 2007, Linus Torvalds wrote: > > So I'd suggest having both jumps back-to-back, but realistically, the > first regular short jump is actually the one that is more important. > That's the one that really matters on i386/i486 class machines, and later > CPU's will generally do the right thing even with _neither_ jump there.
That's obviously badly phrased.
The far jump is obviously required on all CPU's in order for us to actually finally get to 32-bit protected mode and reload CS, but what I *meant* was that we certainly also know that "unreal mode" works and is used by various strange DOS extenders, and that not doing the far jump isn't really required for having a "working setup" - it's just going to be a rather limited mode.
So the short jump is required for the code to *work*. The long jump is required only to get us the 32-bit mode we *want* and out of the odd "half-way" state. Two different issues.
Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |