Hi.
I have xen running on my Macbook. The problem is cause by grub.
When i start the xen entry in grub with the key "return" xen
fails too boot. When i use the "Cursor key right" to start
the xen entry xen boots fine. I used the atached patch against
grub 0.97 for the Intel Macs.
cu
Edgar (gimli) Hucek
Marco Gerards schrieb:
> Hi,
>
> For a while now I have been trying to debug an issue with Xen on the
> MacBook, doing this is part of my Summer of Code project to get Xen
> working properly on the Intel Mac. In case some of you don't know,
> the MacBook is an Intel Core Duo based laptop from Apple, which lacks
> some legacy hardware.
>
> Xen (testing) works perfectly for me when starting it with "nosmp",
> however when not using it, it crashes while starting up the second
> core. There have been some bug report on this issue already.
>
> Below I will explain the problem in more detail and with some
> observations. I will be very grateful if someone can come up with
> ideas of how to fix this or give me some ideas that can lead to a
> solution. Not only Xen has this problem, but so has FreeBSD and
> NetBSD, so a solution will be beneficial to these projects as well.
>
> What happens is the following: The first core sends two IPI
> messages(INIT and STARTUP) to start the second core. When the second
> core is started, it notifies the first core of this so it can continue
> with the boot process. However, the second core is not started by
> these messages, the loop that waits for the second core times out,
> continues and Xen crashes.
>
> One strange thing is that Xen initializes the second core properly
> when you press a key on the keyboard after the IPIs are sent. I am
> expecting this interrupt somehow wakes up the second core so it can
> accept and process the IPIs. Because it is a laptop the second core
> is put in deep sleep mode to save power in case an OS does not use
> this core at all. But as I understand it, it should wake up when an
> INIT IPI arrives.
>
> The problems I am having with Xen can be reproduced with linux when
> booting with "acpi=ht", which means the ACPI interpreter is not
> started.
>
> Hopefully someone has some ideas how to deal with this issue and how
> to properly fix this. If you want more information or want me to test
> things, feel free to ask.
>
> Thanks,
> Marco
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
>
--- grub-0.97.orig/stage2/asm.S 2004-06-19 18:55:22.000000000 +0200
+++ grub-0.97/stage2/asm.S 2006-04-21 11:10:52.000000000 +0200
@@ -1651,7 +1651,29 @@
jnz 3f
ret
-3: /* use keyboard controller */
+3: /*
+ * try to switch gateA20 using PORT92, the "Fast A20 and Init"
+ * register
+ */
+ mov $0x92, %dx
+ inb %dx, %al
+ /* skip the port92 code if it's unimplemented (read returns 0xff) */
+ cmpb $0xff, %al
+ jz 6f
+
+ /* set or clear bit1, the ALT_A20_GATE bit */
+ movb 4(%esp), %ah
+ testb %ah, %ah
+ jz 4f
+ orb $2, %al
+ jmp 5f
+4: and $0xfd, %al
+
+ /* clear the INIT_NOW bit don't accidently reset the machine */
+5: and $0xfe, %al
+ outb %al, %dx
+
+6: /* use keyboard controller */
pushl %eax
call gloop1
@@ -1661,9 +1683,12 @@
gloopint1:
inb $K_STATUS
+ cmpb $0xff, %al
+ jz gloopint1_done
andb $K_IBUF_FUL, %al
jnz gloopint1
+gloopint1_done:
movb $KB_OUTPUT_MASK, %al
cmpb $0, 0x8(%esp)
jz gdoit
@@ -1684,6 +1709,8 @@
gloop1:
inb $K_STATUS
+ cmpb $0xff, %al
+ jz gloop2ret
andb $K_IBUF_FUL, %al
jnz gloop1
@@ -1991,6 +2018,11 @@
ENTRY(console_getkey)
push %ebp
+wait_for_key:
+ call EXT_C(console_checkkey)
+ incl %eax
+ jz wait_for_key
+
call EXT_C(prot_to_real)
.code16
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