From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Sat, 2 Jan 2016 14:52:08 +0000 (+0100)
Subject: inmates: arm: Initialize bss programmatically
X-Git-Url: https://rtime.felk.cvut.cz/gitweb/jailhouse.git/commitdiff_plain/5eb1a649bcdb2650742831e38d3031bf8ca4e09f

inmates: arm: Initialize bss programmatically

Aligns ARM with x86: initialize bss with a small assembly loop before
inmate_main is invoked. This allows to move it after other sections,
effectively removing it from the image file.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

diff --git a/inmates/lib/arm/header.S b/inmates/lib/arm/header.S
index b8501e4..72631cf 100644
--- a/inmates/lib/arm/header.S
+++ b/inmates/lib/arm/header.S
@@ -2,9 +2,11 @@
  * Jailhouse, a Linux-based partitioning hypervisor
  *
  * Copyright (c) ARM Limited, 2014
+ * Copyright (c) Siemens AG, 2016
  *
  * Authors:
  *  Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
+ *  Jan Kiszka <jan.kiszka@siemens.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
@@ -41,6 +43,14 @@ __reset_entry:
 	ldr	r0, =vectors
 	mcr	p15, 0, r0, c12, c0, 0	@ VBAR
 
+	mov	r0, #0
+	ldr	r1, =bss_start
+	ldr	r2, =bss_dwords
+1:	str	r0, [r1]
+	add	r1, #4
+	subs	r2, #1
+	bne	1b
+
 	ldr	sp, =stack_top
 
 	b	inmate_main
diff --git a/inmates/lib/arm/inmate.lds b/inmates/lib/arm/inmate.lds
index d015860..16c4871 100644
--- a/inmates/lib/arm/inmate.lds
+++ b/inmates/lib/arm/inmate.lds
@@ -2,9 +2,11 @@
  * Jailhouse, a Linux-based partitioning hypervisor
  *
  * Copyright (c) ARM Limited, 2014
+ * Copyright (c) Siemens AG, 2016
  *
  * Authors:
  *  Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
+ *  Jan Kiszka <jan.kiszka@siemens.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
@@ -14,11 +16,6 @@ SECTIONS {
 	. = 0;
 	.boot		: { *(.boot) }
 
-	bss_start = .;
-	.bss		: {
-		*(.bss)
-	}
-
 	. = ALIGN(4);
 	.text		: {
 		*(.text)
@@ -32,6 +29,13 @@ SECTIONS {
 		*(.data)
 	}
 
+	.bss		: {
+		bss_start = .;
+		*(.bss)
+		. = ALIGN(4);
+	}
+	bss_dwords = SIZEOF(.bss) / 4;
+
 	. = ALIGN(4096);
 	. += 0x1000;
 	stack_top = .;