From 5768d55a08e163f718bd87498b9e763687ae7137 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <oberpar@linux.ibm.com>
Date: Fri, 16 Sep 2022 15:13:01 +0200
Subject: [PATCH] zipl/boot: add secure boot trailer
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This patch enhances the zipl stage3 loader image adding a trailer as
required for secure boot by future firmware versions.

Note: with the change in this patch the padding via objcopy command line
options is replaced by padding via linker script directives with the
same effect.

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zipl/boot/Makefile     |  2 +-
 zipl/boot/stage3.lds.S | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/zipl/boot/Makefile b/zipl/boot/Makefile
index c2ec76ae..f195df0e 100644
--- a/zipl/boot/Makefile
+++ b/zipl/boot/Makefile
@@ -106,7 +106,7 @@ stage3.bin:	stage3.exec
 		--only-section=.stage2dump.tail \
 		--only-section=.eckd2dump_mv.tail \
 		--only-section=.fixup \
-		--pad-to=0xe000 \
+		--only-section=.sb.trailer \
 		$< $@
 
 data.o: $(FILES)
diff --git a/zipl/boot/stage3.lds.S b/zipl/boot/stage3.lds.S
index fa4c81f7..d8305f11 100644
--- a/zipl/boot/stage3.lds.S
+++ b/zipl/boot/stage3.lds.S
@@ -14,6 +14,7 @@
  */
 
 #include "boot/loaders_layout.h"
+#include "boot/s390.h"
 
 SECTIONS
 {
@@ -46,6 +47,15 @@ SECTIONS
   .rodata : {*(.rodata) }
   .data : { *(.data) }
 
+  /* Trailer needed for Secure Boot */
+  . = COMMAND_LINE_EXTRA - 32;
+  .sb.trailer : {
+    QUAD(0x0000c00000000000)
+    QUAD(STAGE3_ENTRY + PSW_LOAD)
+    QUAD(STAGE3_ENTRY)
+    QUAD(0x000000207a49504c)
+  }
+
   . = COMMAND_LINE_EXTRA;
   .cmdline_extra : {
     . += COMMAND_LINE_EXTRA_SIZE;