[ECOS] i386 HAL, stack segment not initialised

[Ian Campbell <icampbell at arcom dot co dot uk>]

It may be something that I have changed (I don't think so though), but
when booting RedBoot from ROM and then loading an application via GDB it
seems that %ss never gets initialised, this causes a crash on the first
context switch or when changing %esp (at least on the 386ex it does).

The attached patch initialises ss in hal_cpu_init along with the other
data segment registers. I'm not sure this is the correct general
solution, but 'it works for me(tm)'. The patch also contains a rather
pedantic change to make the names used for some registers match the
suffix on the opcode.

Regards,
Ian.



-- 
Ian Campbell
Design Engineer

Arcom Control Systems Ltd,
Clifton Road,
Cambridge CB1 7EA
United Kingdom

Tel: +44 (0)1223 411200 ext. 3204
E-Mail: icampbell@arcom.co.uk
Web: http://www.arcomcontrols.com


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--- platform.inc.orig	Fri Sep 28 10:19:13 2001
+++ platform.inc	Fri Sep 28 10:20:05 2001
@@ -76,8 +76,8 @@
 	lgdt	0
 
 	# Make an IDT pointer in location 0 and load new LDTR
-	movw	$0x77F,%eax
-	movw	%eax,0
+	movw	$0x77F,%ax
+	movw	%ax,0
 	leal	idtStart,%eax
 	movl	%eax,2	
 	lidt	0
@@ -140,6 +140,8 @@
 	movw	%ax, %fs
 	movw	%ax, %gs
 
+	movw	%ax, %ss
+	
 	# Set up SP
 	movl	$__interrupt_stack,%esp