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authorAurelien Jacquiot <a-jacquiot@ti.com>2011-02-23 13:04:59 +0100
committerBernd Schmidt <bernds@codesourcery.com>2011-03-05 18:10:15 +0100
commit46d6a24872b7fa2717f8f71b5e0598a14d38e1f6 (patch)
tree886cf5a54ef7fd260acf2dd7d1722acea1c62186 /libc/sysdeps/linux/c6x/bits/elf-dsbt.h
parent817f685f4c65ed1af6eef79749b1f158eedd5bfc (diff)
The C6X port
This adds support for the TI C6X family of processors. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com> Signed-off-by: Bernd Schmidt <bernds@codesourcery.com>
Diffstat (limited to 'libc/sysdeps/linux/c6x/bits/elf-dsbt.h')
-rw-r--r--libc/sysdeps/linux/c6x/bits/elf-dsbt.h123
1 files changed, 123 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/c6x/bits/elf-dsbt.h b/libc/sysdeps/linux/c6x/bits/elf-dsbt.h
new file mode 100644
index 000000000..ff8b24bd7
--- /dev/null
+++ b/libc/sysdeps/linux/c6x/bits/elf-dsbt.h
@@ -0,0 +1,123 @@
+/* Copyright (C) 2010 Texas Instruments Incorporated
+
+Borrowed heavily from frv arch:
+Copyright 2003, 2004 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 Lesser General Public License as
+published by the Free Software Foundation; either version 2.1 of the
+License, or (at your option) any later version.
+
+In addition to the permissions in the GNU Lesser General Public
+License, the Free Software Foundation gives you unlimited
+permission to link the compiled version of this file with other
+programs, and to distribute those programs without any restriction
+coming from the use of this file. (The GNU Lesser General Public
+License restrictions do apply in other respects; for example, they
+cover modification of the file, and distribution when not linked
+into another program.)
+
+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 Lesser 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. */
+
+#ifndef _BITS_ELF_DSBT_H
+#define _BITS_ELF_DSBT_H
+
+/* These data structures are described in the DSBT ABI.
+ The kernel passes a process a memory map of logical
+ load segments. For PIC code to work, all code segments
+ must be combined into a single mapping while maintaining
+ their relationship to one another. The same is true for
+ RW data segments.
+
+ Furthermore,
+ segment there is an elf32_dsbt_loadseg entry. A pointer to an
+ elf32_dsbt_loadmap is passed in GR8 at start-up, and a pointer to
+ an additional such map is passed in GR9 for the interpreter, when
+ there is one. */
+
+#include <elf.h>
+
+/* This data structure represents a PT_LOAD segment. */
+struct elf32_dsbt_loadseg
+{
+ /* Core address to which the segment is mapped. */
+ Elf32_Addr addr;
+ /* VMA recorded in the program header. */
+ Elf32_Addr p_vaddr;
+ /* Size of this segment in memory. */
+ Elf32_Word p_memsz;
+};
+
+struct elf32_dsbt_loadmap {
+ /* Protocol version number, must be zero. */
+ Elf32_Word version;
+
+ /* Pointer to DSBT */
+ unsigned *dsbt_table;
+ unsigned dsbt_size;
+ unsigned dsbt_index;
+
+ /* number of segments */
+ Elf32_Word nsegs;
+
+ /* The actual memory map. */
+ struct elf32_dsbt_loadseg segs[0];
+};
+
+struct elf32_dsbt_loadaddr {
+ struct elf32_dsbt_loadmap *map;
+};
+
+
+/* Map a pointer's VMA to its corresponding address according to the
+ load map. */
+static __always_inline void *
+__reloc_pointer (void *p,
+ const struct elf32_dsbt_loadmap *map)
+{
+ int c;
+
+#if 0
+ if (map->version != 0)
+ /* Crash. */
+ ((void(*)())0)();
+#endif
+
+ /* No special provision is made for NULL. We don't want NULL
+ addresses to go through relocation, so they shouldn't be in
+ .rofixup sections, and, if they're present in dynamic
+ relocations, they shall be mapped to the NULL address without
+ undergoing relocations. */
+
+ for (c = 0; c < map->nsegs; c++)
+ {
+ unsigned long offset = p - (void*)map->segs[c].p_vaddr;
+ /* We only check for one-past-the-end for the second segment,
+ assumed to be the data segment, because other cases are
+ ambiguous in the absence of padding between segments, and
+ rofixup already serves as padding between text and data.
+ Unfortunately, unless we special-case the second segment,
+ we fail to relocate the _end symbol. */
+ if (offset < map->segs[c].p_memsz
+ || (offset == map->segs[c].p_memsz && c == 1))
+ return (char*)map->segs[c].addr + offset;
+ }
+
+ /* We might want to crash instead. */
+ return (void*)-1;
+}
+
+# define __RELOC_POINTER(ptr, loadaddr) \
+ (__reloc_pointer ((void*)(ptr), \
+ (loadaddr).map))
+
+#endif /* _BITS_ELF_DSBT_H */