The attached patches fixes the problems found bringing up uclibc on coldfire

M5485 processor

1.  Disable mmap2() if we're compiling for coldfire and fall back to mmap().
    It seems to map a different file area on a 2.6.25 linux kernel.

2.  Uses pc-relative addresing[1], computes ADDR_ALIGN, PAGE_ALIGN
    and OFFSET_ALIGN relatively to _dl_pagesize[3]. 
    On coldfire/M5485 _dl_pagesize is 0x2000.

Signed-off-by: Groleo Marius <groleo@gmail.com>

3 files changed, 30 insertions, 9 deletions

diff --git a/ldso/include/dl-syscall.h b/ldso/include/dl-syscall.h
index 1cbbbad0f..0b0b0ef1d 100644
--- a/ldso/include/dl-syscall.h
+++ b/ldso/include/dl-syscall.h
@@ -152,7 +152,7 @@ static __always_inline _syscall2(int, _dl_gettimeofday, struct timeval *, tv,
 # define __NR__dl_mmap __NR_mmap
 static __always_inline _syscall6(void *, _dl_mmap, void *, start, size_t, length,
                         int, prot, int, flags, int, fd, off_t, offset);
-
+#if !defined (__mcoldfire__) // Might be a kernel problem. failed on 2.6.25
 /* then try mmap2() */
 #elif defined(__NR_mmap2)
 
@@ -176,7 +176,7 @@ static __always_inline void * _dl_mmap(void * addr, unsigned long size, int prot
 	return __syscall_mmap2(addr, size, prot, flags,
 	                       fd, (off_t) (offset >> MMAP2_PAGE_SHIFT));
 }
-
+#endif
 /* finally, fall back to mmap(), syscall1() style */
 #elif defined(__NR_mmap)
 
diff --git a/ldso/ldso/m68k/dl-startup.h b/ldso/ldso/m68k/dl-startup.h
index 2c38102a3..13530e05c 100644
--- a/ldso/ldso/m68k/dl-startup.h
+++ b/ldso/ldso/m68k/dl-startup.h
@@ -4,6 +4,17 @@
  * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
  */
 
+/* Perform operation OP with PC-relative SRC as the first operand and
+ * DST as the second.  TMP is available as a temporary if needed.  */
+
+#ifdef __mcoldfire__
+#define PCREL_OP(OP, SRC, DST, TMP, PC) \
+  "move.l #" SRC " - ., " TMP "\n\t" OP " (-8, " PC ", " TMP "), " DST
+#else
+#define PCREL_OP(OP, SRC, DST, TMP, PC) \
+  OP " " SRC "(" PC "), " DST
+#endif
+
 __asm__ ("\
 	.text\n\
 	.globl _start\n\
@@ -21,7 +32,7 @@ _dl_start_user:\n\
 	move.l %d0, %a4\n\
 	# See if we were run as a command with the executable file\n\
 	# name as an extra leading argument.\n\
-	move.l _dl_skip_args(%pc), %d0\n\
+	" PCREL_OP ("move.l", "_dl_skip_args", "%d0", "%d0", "%pc") "\n\
 	# Pop the original argument count\n\
 	move.l (%sp)+, %d1\n\
 	# Subtract _dl_skip_args from it.\n\
@@ -31,7 +42,7 @@ _dl_start_user:\n\
 	# Push back the modified argument count.\n\
 	move.l %d1, -(%sp)\n\
 	# Pass our finalizer function to the user in %a1.\n\
-	lea _dl_fini(%pc), %a1\n\
+	" PCREL_OP ("lea", "_dl_fini", "%a1", "%a1", "%pc") "\n\
 	# Initialize %fp with the stack pointer.\n\
 	move.l %sp, %fp\n\
 	# Jump to the user's entry point.\n\
diff --git a/ldso/ldso/m68k/dl-sysdep.h b/ldso/ldso/m68k/dl-sysdep.h
index 259cb84be..b5eda4e9c 100644
--- a/ldso/ldso/m68k/dl-sysdep.h
+++ b/ldso/ldso/m68k/dl-sysdep.h
@@ -42,19 +42,29 @@ extern unsigned long _dl_linux_resolver (struct elf_resolve *, int);
 static __always_inline Elf32_Addr
 elf_machine_dynamic (void)
 {
-	register Elf32_Addr *got __asm__ ("%a5");
-	return *got;
+	Elf32_Addr got;
+
+	__asm__ ("move.l _DYNAMIC@GOT.w(%%a5), %0"
+			: "=a" (got));
+	return got;
 }
 
+#ifdef __mcoldfire__
+#define PCREL_OP(OP, SRC, DST, TMP, PC) \
+  "move.l #" SRC " - ., " TMP "\n\t" OP " (-8, " PC ", " TMP "), " DST
+#else
+#define PCREL_OP(OP, SRC, DST, TMP, PC) \
+  OP " " SRC "(" PC "), " DST
+#endif
 
 /* Return the run-time load address of the shared object.  */
 static __always_inline Elf32_Addr
 elf_machine_load_address (void)
 {
 	Elf32_Addr addr;
-	__asm__ ("lea _dl_start(%%pc), %0\n\t"
-	     "sub.l _dl_start@GOT.w(%%a5), %0"
-	     : "=a" (addr));
+	__asm__ (PCREL_OP ("lea", "_dl_start", "%0", "%0", "%%pc") "\n\t"
+			"sub.l _dl_start@GOT.w(%%a5), %0"
+			: "=a" (addr));
 	return addr;
 }