Add support for the Meta architecture

Meta cores are 32-bit, hardware multithreaded, general purpose, embedded
processors which also feature a DSP instruction set, and can be found in
many digital radios. They are capable of running different operating
systems on different hardware threads, for example a digital radio might
run RTOSes for DAB decoding and audio decoding on 3 hardware threads,
and run Linux on the 4th hardware thread to manage the user interface,
networking etc. HTPs are also capable of running SMP Linux on multiple
hardware threads.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

6 files changed, 544 insertions, 0 deletions

diff --git a/ldso/ldso/metag/dl-debug.h b/ldso/ldso/metag/dl-debug.h
new file mode 100644
index 000000000..5981d7c73
--- /dev/null
+++ b/ldso/ldso/metag/dl-debug.h
@@ -0,0 +1,27 @@
+/*
+ * Meta ELF shared library loader support.
+ *
+ * Program to load an elf binary on a linux system, and run it.
+ * References to symbols in sharable libraries can be resolved
+ * by either an ELF sharable library or a linux style of shared
+ * library.
+ *
+ * Copyright (C) 2013, Imagination Technologies Ltd.
+ *
+ * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+static const char *_dl_reltypes_tab[] = {
+	[0]  "R_METAG_HIADDR16", "R_METAG_LOADDR16", "R_METAG_ADDR32",
+	[3]  "R_METAG_NONE", "R_METAG_RELBRANCH", "R_METAG_GETSETOFF",
+	[6]  "R_METAG_REG32OP1", "R_METAG_REG32OP2", "R_METAG_REG32OP3",
+	[9]  "R_METAG_REG16OP1", "R_METAG_REG16OP2", "R_METAG_REG16OP3",
+	[12] "R_METAG_REG32OP4", "R_METAG_HIOG", "R_METAG_LOOG",
+	[30] "R_METAG_VTINHERIT", "R_METAG_VTENTRY",
+	[32] "R_METAG_HI16_GOTOFF", "R_METAG_LO16_GOTOFF",
+	[34] "R_METAG_GETSET_GOTOFF", "R_METAG_GETSET_GOT",
+	[36] "R_METAG_HI16_GOTPC", "R_METAG_LO16_GOTPC",
+	[38] "R_METAG_HI16_PLT", "R_METAG_LO16_PLT",
+	[40] "R_METAG_RELBRANCH_PLT", "R_METAG_GOTOFF",
+	[42] "R_METAG_PLT", "R_METAG_COPY", "R_METAG_JMP_SLOT",
+};
diff --git a/ldso/ldso/metag/dl-startup.h b/ldso/ldso/metag/dl-startup.h
new file mode 100644
index 000000000..8dbf747e1
--- /dev/null
+++ b/ldso/ldso/metag/dl-startup.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ *
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+/*
+ * This code fixes the stack pointer so that the dynamic linker
+ * can find argc, argv and auxvt (Auxillary Vector Table).
+ */
+
+__asm__ (
+"       .text\n"
+"       .global __start\n"
+"       .type   __start,@function\n"
+"	.hidden __start\n"
+"_start:\n"
+"__start:\n"
+"       MSETL   [A0StP++],D0Ar4,D0Ar2\n"
+"       MOV     D1Ar1,D0Ar2\n"
+"       CALLR   D1RtP,__dl_start\n"
+"       GETL    D0Ar2,D1Ar1,[A0StP+#-(1*8)]\n"
+"       GETL    D0Ar4,D1Ar3,[A0StP+#-(2*8)]\n"
+"       SUB     A0StP,A0StP,#(2*8)\n"
+"       MOV     PC,D0Re0\n"
+"       .size __start,.-__start\n"
+"       .previous\n"
+);
+
+
+/*
+ * Get a pointer to the argv array.  On many platforms this can be just
+ * the address if the first argument, on other platforms we need to
+ * do something a little more subtle here.
+ */
+
+#define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long *) ARGS))
+
+
+/* Handle relocation of the symbols in the dynamic loader. */
+static inline
+void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr,
+	unsigned long symbol_addr, unsigned long load_addr, Elf32_Sym *symtab)
+{
+	switch (ELF32_R_TYPE(rpnt->r_info)) {
+		case R_METAG_GLOB_DAT:
+		case R_METAG_JMP_SLOT:
+		case R_METAG_ADDR32:
+			*reloc_addr = symbol_addr;
+			break;
+		case R_METAG_RELATIVE:
+			*reloc_addr = load_addr + rpnt->r_addend;
+			break;
+		case R_METAG_RELBRANCH:
+			*reloc_addr = symbol_addr + rpnt->r_addend - *reloc_addr - 4;
+			break;
+		case R_METAG_NONE:
+			break;
+		default:
+			_dl_exit(1);
+			break;
+	}
+}
diff --git a/ldso/ldso/metag/dl-syscalls.h b/ldso/ldso/metag/dl-syscalls.h
new file mode 100644
index 000000000..70ceab10e
--- /dev/null
+++ b/ldso/ldso/metag/dl-syscalls.h
@@ -0,0 +1,6 @@
+/* stub for arch-specific syscall issues
+ *
+ * Copyright (C) 2013, Imagination Technologies Ltd.
+ *
+ * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
diff --git a/ldso/ldso/metag/dl-sysdep.h b/ldso/ldso/metag/dl-sysdep.h
new file mode 100644
index 000000000..55e8d1f66
--- /dev/null
+++ b/ldso/ldso/metag/dl-sysdep.h
@@ -0,0 +1,98 @@
+/*
+ * Meta can never use Elf32_Rel relocations.
+ *
+ * Copyright (C) 2013, Imagination Technologies Ltd.
+ *
+ * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#define ELF_USES_RELOCA
+
+#include <elf.h>
+
+/* Initialization sequence for the GOT.  */
+#define INIT_GOT(GOT_BASE,MODULE)				\
+{								\
+	GOT_BASE[1] = (unsigned long) MODULE; 			\
+	GOT_BASE[2] = (unsigned long) _dl_linux_resolve; 	\
+}
+
+/* Maximum unsigned GOT [GS]ETD offset size, ie. 2^(11+2). */
+#define GOT_REG_OFFSET 0x2000
+
+/* Defined some magic numbers that this ld.so should accept. */
+#define MAGIC1 EM_METAG
+#undef  MAGIC2
+#define ELF_TARGET "META"
+
+/* Need bootstrap relocations */
+#define ARCH_NEEDS_BOOTSTRAP_RELOCS
+
+struct elf_resolve;
+extern unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry);
+
+/* Variable page size. */
+#define ADDR_ALIGN (_dl_pagesize - 1)
+#define PAGE_ALIGN (~ADDR_ALIGN)
+#define OFFS_ALIGN (PAGE_ALIGN & ~(1ul << (sizeof(_dl_pagesize) * 8 - 1)))
+
+/* The union of reloc-type-classes where the reloc TYPE is a member.
+
+   TYPE is in the class ELF_RTYPE_CLASS_NOCOPY if it should not be allowed
+   to resolve to one of the main executable's symbols, as for a COPY
+   reloc.  */
+#define elf_machine_type_class(type)				\
+  (((((type) == R_METAG_JMP_SLOT)) * ELF_RTYPE_CLASS_PLT)	\
+   | (((type) == R_METAG_COPY) * ELF_RTYPE_CLASS_COPY))
+
+static inline Elf32_Addr
+elf_machine_dynamic(Elf32_Ehdr *header)
+{
+	Elf32_Addr *got;
+
+	__asm__ ("MOV %0,A1LbP" : "=r" (got));
+
+	if (header->e_ident[EI_ABIVERSION] >= 1) {
+		/* GOT register offset was introduced with ABI v1 */
+		got = (Elf32_Addr*)((void*)got - GOT_REG_OFFSET);
+	}
+	return *got;
+}
+
+#define DL_BOOT_COMPUTE_GOT(GOT) \
+    ((GOT) = elf_machine_dynamic(header))
+
+static inline Elf32_Addr
+elf_machine_load_address(void)
+{
+	Elf32_Addr addr;
+	__asm__ ("MOV  D1Ar1,A1LbP\n"
+		 "ADDT D1Ar1,D1Ar1,#HI(__dl_start@GOTOFF)\n"
+		 "ADD  D1Ar1,D1Ar1,#LO(__dl_start@GOTOFF)\n"
+		 "ADDT D0Ar2,D0Ar2,#HI(__dl_start_addr@GOTOFF)\n"
+		 "ADD  D0Ar2,D0Ar2,#LO(__dl_start_addr@GOTOFF)\n"
+		 "GETD D0Ar2,[D0Ar2]\n"
+		 "SUB  %0,D1Ar1,D0Ar2\n"
+		 ".section .data\n"
+		 "__dl_start_addr: .long __dl_start\n"
+		 ".previous\n"
+		 : "=d" (addr) : : "D1Ar1", "D0Ar2");
+	return addr;
+}
+
+static inline void
+elf_machine_relative(Elf32_Addr load_off, const Elf32_Addr rel_addr,
+                     Elf32_Word relative_count)
+{
+	Elf32_Rela *rpnt = (void *)rel_addr;
+
+	--rpnt;
+	do {
+		Elf32_Addr *const reloc_addr =
+			(void *)(load_off + (++rpnt)->r_offset);
+
+		*reloc_addr =  load_off + rpnt->r_addend;
+	} while (--relative_count);
+}
+
+#define DL_MALLOC_ALIGN 8
diff --git a/ldso/ldso/metag/elfinterp.c b/ldso/ldso/metag/elfinterp.c
new file mode 100644
index 000000000..78434167b
--- /dev/null
+++ b/ldso/ldso/metag/elfinterp.c
@@ -0,0 +1,299 @@
+/*
+ * Meta ELF shared library loader support.
+ *
+ * Program to load an elf binary on a linux system, and run it.
+ * References to symbols in sharable libraries can be resolved
+ * by either an ELF sharable library or a linux style of shared
+ * library.
+ *
+ * Copyright (C) 2013, Imagination Technologies Ltd.
+ *
+ * Licensed under LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#include "ldso.h"
+
+/* Defined in resolve.S. */
+extern int _dl_linux_resolve(void);
+
+static inline unsigned long __get_unaligned_reloc(unsigned long *addr)
+{
+	char *rel_addr = (char *)addr;
+	unsigned long val;
+
+	val = *rel_addr++ & 0xff;
+	val |= (*rel_addr++ << 8) & 0x0000ff00;
+	val |= (*rel_addr++ << 16) & 0x00ff0000;
+	val |= (*rel_addr++ << 24) & 0xff000000;
+
+	return val;
+}
+
+static inline void __put_unaligned_reloc(unsigned long *addr,
+					 unsigned long val)
+{
+	char *rel_addr = (char *)addr;
+
+	*rel_addr++ = (val & 0x000000ff);
+	*rel_addr++ = ((val & 0x0000ff00) >> 8);
+	*rel_addr++ = ((val & 0x00ff0000) >> 16);
+	*rel_addr++ = ((val & 0xff000000) >> 24);
+}
+
+unsigned long
+_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
+{
+	int reloc_type;
+	int symtab_index;
+	char *strtab;
+	char *symname;
+	char *new_addr;
+	char *rel_addr;
+	char **got_addr;
+	Elf32_Sym *symtab;
+	ELF_RELOC *this_reloc;
+	unsigned long instr_addr;
+
+	rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
+
+	this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry);
+	reloc_type = ELF32_R_TYPE(this_reloc->r_info);
+	symtab_index = ELF32_R_SYM(this_reloc->r_info);
+
+	symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
+	strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+	symname = strtab + symtab[symtab_index].st_name;
+
+	if (unlikely(reloc_type != R_METAG_JMP_SLOT)) {
+		_dl_dprintf(2, "%s: Incorrect relocation type in jump relocations\n",
+			    _dl_progname);
+		_dl_exit(1);
+	}
+
+	/* Address of the jump instruction to fix up. */
+	instr_addr = ((unsigned long)this_reloc->r_offset +
+		      (unsigned long)tpnt->loadaddr);
+	got_addr = (char **)instr_addr;
+
+	/* Get the address of the GOT entry. */
+	new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt,
+			ELF_RTYPE_CLASS_PLT, NULL);
+	if (unlikely(!new_addr)) {
+		_dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname);
+		_dl_exit(1);
+	}
+
+#if defined (__SUPPORT_LD_DEBUG__)
+	if (_dl_debug_bindings) {
+		_dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
+		if (_dl_debug_detail)
+			_dl_dprintf(_dl_debug_file,
+				    "\n\tpatched: %x ==> %x @ %x\n",
+				    *got_addr, new_addr, got_addr);
+	}
+	if (!_dl_debug_nofixups) {
+		*got_addr = new_addr;
+	}
+#else
+	*got_addr = new_addr;
+#endif
+
+	return (unsigned long)new_addr;
+}
+
+static int
+_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
+	  unsigned long rel_addr, unsigned long rel_size,
+	  int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
+			   ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab))
+{
+	int symtab_index;
+	unsigned int i;
+	char *strtab;
+	Elf32_Sym *symtab;
+	ELF_RELOC *rpnt;
+
+	/* Parse the relocation information. */
+	rpnt = (ELF_RELOC *)(intptr_t)rel_addr;
+	rel_size /= sizeof(ELF_RELOC);
+
+	symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
+	strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
+
+	for (i = 0; i < rel_size; i++, rpnt++) {
+		int res;
+
+		symtab_index = ELF32_R_SYM(rpnt->r_info);
+
+		debug_sym(symtab, strtab, symtab_index);
+		debug_reloc(symtab, strtab, rpnt);
+
+		/* Pass over to actual relocation function. */
+		res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
+
+		if (res == 0)
+			continue;
+
+		_dl_dprintf(2, "\n%s: ", _dl_progname);
+
+		if (symtab_index)
+			_dl_dprintf(2, "symbol '%s': ",
+				    strtab + symtab[symtab_index].st_name);
+
+		if (unlikely(res < 0)) {
+			int reloc_type = ELF32_R_TYPE(rpnt->r_info);
+
+#if defined (__SUPPORT_LD_DEBUG__)
+			_dl_dprintf(2, "can't handle reloc type %s\n",
+				    _dl_reltypes(reloc_type));
+#else
+			_dl_dprintf(2, "can't handle reloc type %x\n",
+				    reloc_type);
+#endif
+			_dl_exit(-res);
+		} else if (unlikely(res > 0)) {
+			_dl_dprintf(2, "can't resolve symbol\n");
+			return res;
+		}
+	}
+
+	return 0;
+}
+
+static int
+_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+	     ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
+{
+	int reloc_type;
+	int symtab_index;
+	char *symname = NULL;
+	unsigned long *reloc_addr;
+	unsigned long symbol_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+	unsigned long old_val;
+#endif
+
+	reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+	reloc_type = ELF32_R_TYPE(rpnt->r_info);
+	symtab_index = ELF32_R_SYM(rpnt->r_info);
+	symbol_addr = 0;
+	symname = strtab + symtab[symtab_index].st_name;
+
+	if (symtab_index) {
+		if (symtab[symtab_index].st_shndx != SHN_UNDEF &&
+		    ELF32_ST_BIND(symtab[symtab_index].st_info) == STB_LOCAL) {
+			symbol_addr = (unsigned long)tpnt->loadaddr;
+		} else {
+		  symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt,
+							     elf_machine_type_class(reloc_type), NULL);
+		}
+
+		if (unlikely(!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) {
+			_dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
+			_dl_exit(1);
+		};
+
+		symbol_addr += rpnt->r_addend;
+	}
+
+#if defined (__SUPPORT_LD_DEBUG__)
+	if (reloc_type != R_METAG_NONE)
+		old_val = __get_unaligned_reloc(reloc_addr);
+#endif
+
+	switch (reloc_type) {
+		case R_METAG_NONE:
+			break;
+		case R_METAG_GLOB_DAT:
+		case R_METAG_JMP_SLOT:
+		case R_METAG_ADDR32:
+			__put_unaligned_reloc(reloc_addr, symbol_addr);
+			break;
+		case R_METAG_COPY:
+#if defined (__SUPPORT_LD_DEBUG__)
+			if (_dl_debug_move)
+				_dl_dprintf(_dl_debug_file,
+					    "\t%s move %d bytes from %x to %x\n",
+					    symname, symtab[symtab_index].st_size,
+					    symbol_addr, reloc_addr);
+#endif
+
+			_dl_memcpy((char *)reloc_addr,
+				   (char *)symbol_addr,
+				   symtab[symtab_index].st_size);
+			break;
+		case R_METAG_RELATIVE:
+			__put_unaligned_reloc(reloc_addr,
+					      (unsigned long)tpnt->loadaddr +
+					      rpnt->r_addend);
+			break;
+		default:
+			return -1;	/* Calls _dl_exit(1). */
+	}
+
+#if defined (__SUPPORT_LD_DEBUG__)
+	if (_dl_debug_reloc && _dl_debug_detail &&
+	    (reloc_type != R_METAG_NONE)) {
+		unsigned long new_val = __get_unaligned_reloc(reloc_addr);
+		_dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
+			    old_val, new_val, reloc_addr);
+	}
+#endif
+
+	return 0;
+}
+
+static int
+_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
+		  ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
+{
+	int reloc_type;
+	unsigned long *reloc_addr;
+#if defined (__SUPPORT_LD_DEBUG__)
+	unsigned long old_val;
+#endif
+
+	reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
+	reloc_type = ELF32_R_TYPE(rpnt->r_info);
+
+#if defined (__SUPPORT_LD_DEBUG__)
+	old_val = *reloc_addr;
+#endif
+
+	switch (reloc_type) {
+		case R_METAG_NONE:
+			break;
+		case R_METAG_JMP_SLOT:
+			*reloc_addr += (unsigned long)tpnt->loadaddr;
+			break;
+		default:
+			return -1;	/* Calls _dl_exit(1). */
+	}
+
+#if defined (__SUPPORT_LD_DEBUG__)
+	if (_dl_debug_reloc && _dl_debug_detail)
+		_dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
+			    old_val, *reloc_addr, reloc_addr);
+#endif
+
+	return 0;
+}
+
+/* External interface to the generic part of the dynamic linker. */
+
+void
+_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
+				      unsigned long rel_addr,
+				      unsigned long rel_size)
+{
+	_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
+}
+
+int
+_dl_parse_relocation_information(struct dyn_elf *rpnt,
+				 unsigned long rel_addr,
+				 unsigned long rel_size)
+{
+	return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr,
+			 rel_size, _dl_do_reloc);
+}
diff --git a/ldso/ldso/metag/resolve.S b/ldso/ldso/metag/resolve.S
new file mode 100644
index 000000000..8f23a340a
--- /dev/null
+++ b/ldso/ldso/metag/resolve.S
@@ -0,0 +1,51 @@
+/*
+ * Meta dynamic resolver
+ *
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ *
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ *
+ * This function is _not_ called directly.  It is jumped to (so no return
+ * address is on the stack) when attempting to use a symbol that has not yet
+ * been resolved.  The first time a jump symbol (such as a function call inside
+ * a shared library) is used (before it gets resolved) it will jump here to
+ * _dl_linux_resolve.  When we get called the stack looks like this:
+ *	reloc_entry
+ *	tpnt
+ *
+ * This function saves all the registers then makes the function call
+ * _dl_linux_resolver(tpnt, reloc_entry).  _dl_linux_resolver() figures out
+ * where the jump symbol is _really_ supposed to have jumped to and returns
+ * that to us.  Once we have that, we overwrite tpnt with this fixed up
+ * address. We then clean up after ourselves, put all the registers back how we
+ * found them, then we jump to the fixed up address, which is where the jump
+ * symbol that got us here really wanted to jump to in the first place.
+ *  -Erik Andersen
+ */
+
+	.text
+	.global __dl_linux_resolve
+	.type   __dl_linux_resolve,@function
+
+__dl_linux_resolve:
+	!! Save registers on the stack. Do we need to save any more here?
+	MSETL [A0StP++],D0Ar6,D0Ar4,D0Ar2,D0FrT
+	SETL  [A0StP++],A0FrP,A1LbP
+	!! Get the args for _dl_linux_resolver off the stack
+	GETL  D0Re0,D1Re0,[A0StP+#-(6*8)]
+	GETD  D1Ar1,[D0Re0]
+	MOV   D0Ar2,D1Re0
+	!! Multiply plt_index by sizeof(Elf32_Rela)
+	MULW  D0Ar2,D0Ar2,#12
+	!! Call the resolver
+	CALLR D1RtP,__dl_linux_resolver
+	!! Restore the registers from the stack
+	SUB   A0.2,A0StP,#(1*8)
+	GETL  A0FrP,A1LbP,[A0.2]
+	SUB   A0.2,A0.2,#(4*8)
+	MGETL D0Ar6,D0Ar4,D0Ar2,D0FrT,[A0.2]
+	!! Also take into account args pushed by PLT
+	SUB   A0StP,A0StP,#(6*8)
+	!! Jump to the resolved address
+	MOV   PC,D0Re0
+	.size __dl_linux_resolve, .-__dl_linux_resolve