Removed bogus padding that wasted 0x500 bytes.

Improved code and comments.  Don't do anything except transfer control
in the head.o module.

sys/i386/boot/kzipboot/head.S

@@ -1,13 +1,11 @@
 /*
- * Leader for kernel
- * This needs to be at the beginning, so the start address is passed
- * to the boot loader
+ * First module in a kzipped kernel.
+ * This needs to be at the beginning so that the boot loader calls it.
+ * It may be overwritten by uncompressing the kernel, so it transfers
+ * control to a higher address that won't be overwritten.
+ *
  * Copyright (C) Serge Vakulenko
  */
 	.text
-	.globl	kzstart
-kzstart:
-	cli                             # disable interrupts
-	call   start			# unpack the kernel image
-					# never return here.
-	. = kzstart + 0x500		# skip warm boot stuff
+head:
+	jmp	tail

sys/i386/boot/kzipboot/tail.S

@@ -3,10 +3,10 @@
  * Copyright (C) Serge Vakulenko
  */
 	.text
-	.globl	start
-start:
-	popl	%eax			# remove return addr
+	.globl	tail
+tail:
+	cli				# disable interrupts
 	pushl	4(%esp)			# pass howto arg
-	call    _boot                   # unpack the kernel image
+	call	_boot			# unpack the kernel image
 	popl	%eax			# discard howto arg
-	ljmp    $CSEG, $KADDR           # jump to unpacked kernel
+	ljmp	$CSEG, $KADDR		# jump to unpacked kernel