From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 15 Mar 2010 23:58:55 +0000 (-0400)
Subject: Restore segment limits in handle_1589 code.
X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=commitdiff_plain;h=c35e1e50c389c6d63227e7f8d922cbcf4dea68aa;p=seabios.git

Restore segment limits in handle_1589 code.

Before transitioning back to real mode, the segment registers should
be reloaded so that the hidden register limits are updated.
---

diff --git a/src/system.c b/src/system.c
index f3031af..898c3cc 100644
--- a/src/system.c
+++ b/src/system.c
@@ -143,6 +143,11 @@ handle_1587(struct bregs *regs)
         "  xorw %%di, %%di\n"
         "  rep movsw\n"
 
+        // Restore DS and ES segment limits to 0xffff
+        "  movw $(5<<3), %%ax\n" // 5th descriptor in table (SS)
+        "  movw %%ax, %%ds\n"
+        "  movw %%ax, %%es\n"
+
         // Disable protected mode
         "  movl %%cr0, %%eax\n"
         "  andl $~" __stringify(CR0_PE) ", %%eax\n"