Major revisions to documentation.

[pintos-anon] / src / threads / loader.S

diff --git a/src/threads/loader.S b/src/threads/loader.S
index 2d76763cffc3dcdc2aa339404bfb674360e22ae1..ca79cdfda730cf75ba173750feb1aa76d0776bc2 100644 (file)
--- a/src/threads/loader.S
+++ b/src/threads/loader.S
@@ -220,6 +220,17 @@ start:
 
        movl $1, %ebx
        movl $LOADER_KERN_BASE + LOADER_PHYS_BASE, %edi
+
+# Disable interrupt delivery by IDE controller, because we will be
+# polling for data.
+# (If we don't do this, Bochs 2.2.6 will never deliver any IDE
+# interrupt to us later after we reset the interrupt controller during
+# boot, even if we also reset the IDE controller.)
+
+       movw $0x3f6, %dx
+       movb $0x02, %al
+       outb %al, %dx
+       
 read_sector:
 
 # Poll status register while controller busy.