Sat Feb 10 13:09:03 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/unix/sysv/linux/sys/mman.h: Define MAP_ANON and
	MAP_FILE if not already defined.

	* elf/elf.h: Add m68k reloc definitions.
	* sysdeps/m68k/dl-machine.h, sysdeps/m68k/elf/start.S: New files.
Sat Feb 10 13:09:03 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/unix/sysv/linux/sys/mman.h: Define MAP_ANON and
	MAP_FILE if not already defined.

	* elf/elf.h: Add m68k reloc definitions.
	* sysdeps/m68k/dl-machine.h, sysdeps/m68k/elf/start.S: New files.

2 files changed, 320 insertions, 0 deletions

diff --git a/sysdeps/m68k/dl-machine.h b/sysdeps/m68k/dl-machine.h
new file mode 100644
index 0000000000..2208cd2259
--- /dev/null
+++ b/sysdeps/m68k/dl-machine.h
@@ -0,0 +1,230 @@
+/* Machine-dependent ELF dynamic relocation inline functions.  m68k version.
+Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#define ELF_MACHINE_NAME "m68k"
+
+#include <assert.h>
+#include <string.h>
+#include <link.h>
+
+
+/* Return nonzero iff E_MACHINE is compatible with the running host.  */
+static inline int
+elf_machine_matches_host (Elf32_Half e_machine)
+{
+  switch (e_machine)
+    {
+    case EM_68K:
+      return 1;
+    default:
+      return 0;
+    }
+}
+
+
+/* Return the run-time address of the _GLOBAL_OFFSET_TABLE_.
+   Must be inlined in a function which uses global data.  */
+static inline Elf32_Addr *
+elf_machine_got (void)
+{
+  register Elf32_Addr *got asm ("%a5");
+  return got;
+}
+
+
+/* Return the run-time load address of the shared object.  */
+static inline Elf32_Addr
+elf_machine_load_address (void)
+{
+  ...
+}
+
+/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
+   MAP is the object containing the reloc.  */
+
+static inline void
+elf_machine_rela (struct link_map *map,
+		  const Elf32_Rela *reloc,
+		  Elf32_Addr sym_loadaddr, const Elf32_Sym *sym)
+{
+  Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+  const Elf32_Addr sym_value = sym ? sym_loadaddr + sym->st_value : 0;
+
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_68K_COPY:
+      memcpy (reloc_addr, (void *) sym_value, sym->st_size);
+      break;
+    case R_68K_GLOB_DAT:
+    case R_68K_JMP_SLOT:
+      *reloc_addr = sym_value;
+      break;
+    case R_68K_8:
+      *(char *) reloc_addr = sym_value + reloc->r_addend;
+      break;
+    case R_68K_16:
+      *(short *) reloc_addr = sym_value + reloc->r_addend;
+      break;
+    case R_68K_32:
+      *reloc_addr = sym_value + reloc->r_addend;
+      break;
+    case R_68K_RELATIVE:
+      *reloc_addr = map->l_addr + reloc->r_addend;
+      break;
+    case R_68K_PC8:
+      *(char *) reloc_addr = (sym_value + reloc->r_addend
+			      - (Elf32_Addr) reloc_addr);
+      break;
+    case R_68K_PC16:
+      *(short *) reloc_addr = (sym_value + reloc->r_addend
+			       - (Elf32_Addr) reloc_addr);
+      break;
+    case R_68K_PC32:
+      *reloc_addr = sym_value + reloc->r_addend - (Elf32_Addr) reloc_addr;
+      break;
+    case R_68K_NONE:		/* Alright, Wilbur.  */
+      break;
+    default:
+      assert (! "unexpected dynamic reloc type");
+      break;
+    }
+}
+
+static inline void
+elf_machine_lazy_rel (struct link_map *map, const Elf32_Rela *reloc)
+{
+  Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_68K_NONE:
+      break;
+    case R_68K_JMP_SLOT:
+      *reloc_addr += map->l_addr;
+      break;
+    default:
+      assert (! "unexpected PLT reloc type");
+      break;
+    }
+}
+
+/* The m68k never uses Elf32_Rel relocations.  */
+#define ELF_MACHINE_NO_REL 1
+
+
+/* Set up the loaded object described by L so its unrelocated PLT
+   entries will jump to the on-demand fixup code in dl-runtime.c.  */
+
+static inline void
+elf_machine_runtime_setup (struct link_map *l, int lazy)
+{
+  Elf32_Addr *got;
+  extern void _dl_runtime_resolve (Elf32_Word);
+
+  if (l->l_info[DT_JMPREL] && lazy)
+    {
+      /* The GOT entries for functions in the PLT have not yet been
+	 filled in.  Their initial contents will arrange when called
+	 to push an offset into the .rela.plt section, push
+	 _GLOBAL_OFFSET_TABLE_[1], and then jump to
+	 _GLOBAL_OFFSET_TABLE_[2].  */
+      got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);
+      got[1] = (Elf32_Addr) l;	/* Identify this shared object.  */
+      /* This function will get called to fix up the GOT entry
+	 indicated by the offset on the stack, and then jump to the
+	 resolved address.  */
+      got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+    }
+
+  /* This code is used in dl-runtime.c to call the `fixup' function
+     and then redirect to the address it returns.  */
+#define ELF_MACHINE_RUNTIME_TRAMPOLINE asm ("\
+| Trampoline for _dl_runtime_resolver
+	.globl _dl_runtime_resolve
+	.type _dl_runtime_resolve, @function
+_dl_runtime_resolve:
+	| Save %a0 (struct return address).
+	move.l %a0, -(%sp)
+	| Call the real address resolver.
+	bsr.l fixup
+	| Restore register %a0.
+	move.l (%sp)+, %a0
+	| Pop parameters
+	addq.l #8, %sp
+	| Call real function.
+	jmp (%d0)
+	.size _dl_runtime_resolve, . - _dl_runtime_resolve
+");
+#define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0
+}
+
+
+/* Mask identifying addresses reserved for the user program,
+   where the dynamic linker should not map anything.  */
+#define ELF_MACHINE_USER_ADDRESS_MASK	0x80000000UL
+
+/* Initial entry point code for the dynamic linker.
+   The C function `_dl_start' is the real entry point;
+   its return value is the user program's entry point.  */
+
+#define RTLD_START asm ("\
+.text
+.globl _start
+.globl _dl_start_user
+_start:
+	jbsr _dl_start
+_dl_start_user:
+	| Save the user entry point address in %a4.
+	move.l %d0, %a4
+	| Point %a5 at the GOT.
+	lea _GLOBAL_OFFSET_TABLE_@GOTPC(%pc), %a5
+	| See if we were run as a command with the executable file
+	| name as an extra leading argument.
+	move.l ([_dl_skip_args@GOT, %a5]), %d0
+	jeq 0f
+	| Pop the original argument count
+	move.l (%sp)+, %d1
+	| Subtract _dl_skip_args from it.
+	sub.l %d0, %d1
+	| Adjust the stack pointer to skip _dl_skip_args words.
+	lea (%sp, %d0*4), %sp
+	| Push back the modified argument count.
+	move.l %d1, -(%sp)
+	| Call _dl_init_next to return the address of an initializer
+	| function to run.
+0:	bsr.l _dl_init_next@PLTPC
+	| Check for zero return, when out of initializers.
+	tst.l %d0
+	jeq 1f
+	| Call the shared object initializer function.
+	| NOTE: We depend only on the registers (%a4 and %a5)
+	| and the return address pushed by this call;
+	| the initializer is called with the stack just
+	| as it appears on entry, and it is free to move
+	| the stack around, as long as it winds up jumping to
+	| the return address on the top of the stack.
+	move.l %d0, %a0
+	jsr (%a0)
+	| Loop to call _dl_init_next for the next initializer.
+	jra 0b
+1:	| Pass our finalizer function to the user in %a1.
+	move.l _dl_fini@GOT(%a5), %a1
+	| Initialize %fp with the stack pointer.
+	move.l %sp, %fp
+	| Jump to the user's entry point.
+	jmp (%a4)");
diff --git a/sysdeps/m68k/elf/start.S b/sysdeps/m68k/elf/start.S
new file mode 100644
index 0000000000..1b622d6e08
--- /dev/null
+++ b/sysdeps/m68k/elf/start.S
@@ -0,0 +1,90 @@
+/* Startup code compliant to the ELF m68k ABI.
+Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/* This is the canonical entry point, usually the first thing in the text
+   segment.  The SVR4/m68k ABI says that when the entry point runs,
+   most registers' values are unspecified, except for:
+
+   %a1		Contains a function pointer to be registered with `atexit'.
+   		This is how the dynamic linker arranges to have DT_FINI
+		functions called for shared libraries that have been loaded
+		before this code runs.
+
+   %sp		The stack contains the arguments and environment:
+   		0(%sp)			argc
+		4(%sp)			argv[0]
+		...
+		(4*argc)(%sp)		NULL
+		(4*(argc+1))(%sp)	envp[0]
+		...
+					NULL
+*/
+
+	.text	
+	.globl _start
+_start:
+	/* Clear the frame pointer.  The ABI suggests this be done, to mark
+	   the outermost frame obviously.  */
+	sub.l %fp, %fp
+
+	/* %a1 contains the address of the shared library termination
+	   function, which we will register with `atexit' to be called by
+	   `exit'.  */
+	tstl %a1
+	jbeq 1f
+	move.l %a1, -(%sp)
+	jbsr atexit
+	addql #4, %sp
+1:
+
+	/* Do essential libc initialization.  In statically linked
+	   programs under the GNU Hurd, this is what sets up the
+	   arguments on the stack for the code below.  */
+	jbsr __libc_init_first
+
+	/* Extract the arguments and environment as encoded on the stack
+	   and set up the arguments for `main': argc, argv, envp.  */
+	move.l (%sp)+, %d0	/* Pop the argument count.  */
+	lea (4,%sp,%d0*4), %a0	/* envp = &argv[argc + 1] */
+	move.l %a0, _environ	/* Store it in the global variable.  */
+	pea (%a0)		/* Push third argument: envp.  */
+	pea 4(%sp)		/* Push second argument: argv.  */
+	move.l %d0, -(%sp)	/* Push first argument: argc.  */
+
+	/* Call `_init', which is the entry point to our own `.init'
+	   section; and register with `atexit' to have `exit' call
+	   `_fini', which is the entry point to our own `.fini' section.  */
+	jbsr _init
+	move.l #_fini, -(%sp)
+	jbsr atexit
+	addq.l #4, %sp
+
+	/* Call the user's main function, and exit with its value.  */
+	jbsr main
+	move.l %d0, (%sp)
+1:	jbsr exit		/* This should never return.  */
+	jbra 1b			/* Try again if somehow it does return.  */
+
+/* Define a symbol for the first piece of initialized data.  */
+	.data
+	.globl __data_start
+__data_start:
+	.long 0
+	.weak data_start
+	data_start = __data_start