From 08324d8525c6f5e04a7278296e39fa1ae215823a Mon Sep 17 00:00:00 2001
From: Peng Fan <van.freenix@gmail.com>
Date: Mon, 22 Jul 2013 10:32:42 +0800
Subject: More m68k reloc support

Signed-off-by: Peng Fan <van.freenix@gmail.com>
---
 rtl-mdreloc-m68k.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 testcase/1.c       | 15 +++++++++++++++
 testcase/Readme    | 11 +++++++++++
 testcase/wscript   | 11 +++++++++++
 wscript            |  2 +-
 5 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/rtl-mdreloc-m68k.c b/rtl-mdreloc-m68k.c
index d9459ff..45d1498 100644
--- a/rtl-mdreloc-m68k.c
+++ b/rtl-mdreloc-m68k.c
@@ -16,6 +16,20 @@
 #include "rtl-error.h"
 #include <rtl-trace.h>
 
+static inline int overflow_8_check(int value)
+{
+  if ((value & 0xffffff00) && (~value & 0xffffff80))
+    return true;
+  return false;
+}
+
+static inline int overflow_16_check(int value)
+{
+  if ((value & 0xffff0000) && (~value & 0xffff8000))
+    return true;
+  return false;
+}
+
 bool
 rtems_rtl_elf_rel_resolve_sym (Elf_Word type)
 {
@@ -32,6 +46,7 @@ rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t*      obj,
 {
 	Elf_Addr  target = 0;
   Elf_Addr* where;
+  Elf_Word  tmp;
 
   where = (Elf_Addr *)(sect->base + rela->r_offset);
 
@@ -39,6 +54,31 @@ rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t*      obj,
 		case R_TYPE(NONE):
 			break;
 
+    case R_TYPE(PC8):
+      tmp = symvalue + rela->r_addend - (Elf_Addr)where;
+      if (overflow_8_check(tmp))
+        return false;
+
+      *(uint8_t *)where = tmp;
+
+      if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
+        printf ("rtl: reloc R_TYPE_8/PC8 in %s --> %p (%p) in %s\n",
+                sect->name, (void*) (symvalue + rela->r_addend),
+                (void *)*where, rtems_rtl_obj_oname (obj));
+      break;
+
+    case R_TYPE(PC16):
+      tmp = symvalue + rela->r_addend - (Elf_Addr)where;
+      if (overflow_16_check(tmp))
+        return false;
+
+      *(uint16_t*)where = tmp;
+
+      if (rtems_rtl_trace (RTEMS_RTL_TRACE_RELOC))
+        printf ("rtl: reloc R_TYPE_16/PC16 in %s --> %p (%p) in %s\n",
+                sect->name, (void*) (symvalue + rela->r_addend),
+                (void *)*where, rtems_rtl_obj_oname (obj));
+      break;
 		case R_TYPE(PC32):
       target = (Elf_Addr) symvalue + rela->r_addend;
       *where += target - (Elf_Addr)where;
@@ -92,7 +132,7 @@ rtems_rtl_elf_relocate_rela (const rtems_rtl_obj_t*      obj,
       return false;
   }
 
-  return false;
+  return true;
 }
 
 bool
diff --git a/testcase/1.c b/testcase/1.c
index 58903bc..f3ba414 100644
--- a/testcase/1.c
+++ b/testcase/1.c
@@ -50,7 +50,11 @@ void hello(int arg)
 
 #endif
     default:
+#if defined (__m68k__)
+      printf("M68K PC16 pass\n");
+#else
       printf("no arg in hello\n");
+#endif
       return;
   }
 }
@@ -306,6 +310,17 @@ int rtems(int argc, char **argv)
     printf("R_M32R_32_RELA, .word global pass\n");
 
 #endif
+
+#elif defined (__m68k__)
+  __asm__ volatile (
+      ".align 2\n\t"
+      "subal #4, %%a7\n\t"
+      "lea 1f, %%a0\n\t"
+      "movel %%a0, %%a7@(0)\n\t"
+      "bra hello\n\t" /* R_68K_PC16 */
+      "1:\n\t"
+      "nop\n\t" : : :"a0", "a1"
+      );
 #else
   /* other archs */
 #endif
diff --git a/testcase/Readme b/testcase/Readme
index 5735dc2..ab95292 100644
--- a/testcase/Readme
+++ b/testcase/Readme
@@ -59,3 +59,14 @@ m32r:
 
  Simulator:
     m32rsim-gdb build/m32r-rtems4.11-m32rsim/rtld
+
+M68K:
+ Use the following two patchs and patch them to qemu-0.11.0-rc1
+ http://lists.nongnu.org/archive/html/qemu-devel/2009-09/msg00811.html
+ http://lists.nongnu.org/archive/html/qemu-devel/2009-09/msg00353.html
+
+ http://www.rtems.org/pipermail/rtems-users/2009-September/005941.html shows how
+ to compile and run.
+
+ Simulator:
+   qemu-system-m68k -M uc5282 -nographic -kernel build/m68k-rtems4.11-uC5282/rtld
diff --git a/testcase/wscript b/testcase/wscript
index cad0613..b455b4e 100644
--- a/testcase/wscript
+++ b/testcase/wscript
@@ -121,6 +121,17 @@ def build(bld):
                          '--entry', 'my_main'],
       source = ['1.c', '2.c'])
 
+    elif arch == 'm68k':
+      bld(target = 'test.rap',
+      features = 'c rap',
+      xxxx = 'hello',
+
+      cflags = '-fno-common',
+
+      rtems_linkflags = ['--base', 'rtld.prelink',
+                         '--entry', 'my_main'],
+      source = ['1.c', '2.c'])
+
     bld(target = '../test.rap',
 				source = ['test.rap'],
 				rule = 'cp ${SRC} ${TGT}')
diff --git a/wscript b/wscript
index 41d1491..246e67e 100644
--- a/wscript
+++ b/wscript
@@ -66,7 +66,7 @@ def build(bld):
     #
     # The ARM as special BSP initialise code.
     #
-    if arch == 'arm' or arch == 'powerpc' or arch == 'mips' or arch == 'bfin' or arch == 'h8300' or arch == 'lm32' or arch == 'moxie' or arch == 'v850' or arch == 'm32r':
+    if arch == 'arm' or arch == 'powerpc' or arch == 'mips' or arch == 'bfin' or arch == 'h8300' or arch == 'lm32' or arch == 'moxie' or arch == 'v850' or arch == 'm32r' or arch == 'm68k':
         bld(target = 'bspinit',
             features = 'c',
             includes = bld.includes,
-- 
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