sh: Add ELF relocation support for R_SH_DIR32/R_SH_REL32 relocs.

Simple handler for the common SHcompact ELF relocations.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 40 insertions, 5 deletions

diff --git a/kexec/arch/sh/kexec-elf-rel-sh.c b/kexec/arch/sh/kexec-elf-rel-sh.c
index 3e16b28..c1aaa60 100644
--- a/kexec/arch/sh/kexec-elf-rel-sh.c
+++ b/kexec/arch/sh/kexec-elf-rel-sh.c
@@ -1,3 +1,15 @@
+/*
+ * kexec-elf-rel-sh.c - ELF relocations for SuperH
+ * Copyright (C) 2008 Paul Mundt
+ *
+ * Based on the SHcompact module loader (arch/sh/kernel/module.c) in the
+ * Linux kernel, which is written by:
+ *
+ *	Copyright (C) 2003 - 2008 Kaz Kojima & Paul Mundt
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
 #include <stdio.h>
 #include <elf.h>
 #include "../../kexec.h"
@@ -5,14 +17,37 @@
 
 int machine_verify_elf_rel(struct mem_ehdr *ehdr)
 {
+	/* Intentionally don't bother with endianness validation, it's
+	 * configurable */
 
-        die("machine_verify_elf_rel is not implemented\n");
-	return 0;
+	if (ehdr->ei_class != ELFCLASS32)
+		return 0;
+	if (ehdr->e_machine != EM_SH)
+		return 0;
+
+	return 1;
 }
 
 void machine_apply_elf_rel(struct mem_ehdr *ehdr, unsigned long r_type,
-	void *location, unsigned long address, unsigned long value)
+	void *orig_loc, unsigned long address, unsigned long relocation)
 {
-        die("Unknown rela relocation: %lu\n", r_type);
-	return;
+	uint32_t *location = orig_loc;
+	uint32_t value;
+
+	switch (r_type) {
+	case R_SH_DIR32:
+		value = get_unaligned(location);
+		value += relocation;
+		put_unaligned(value, location);
+		break;
+	case R_SH_REL32:
+		relocation = (relocation - (uint32_t)location);
+		value = get_unaligned(location);
+		value += relocation;
+		put_unaligned(value, location);
+		break;
+	default:
+	        die("Unknown rela relocation: %lu\n", r_type);
+		break;
+	}
 }