diff options
Diffstat (limited to 'sysdeps/sparc')
| -rw-r--r-- | sysdeps/sparc/dl-machine.h | 250 | ||||
| -rw-r--r-- | sysdeps/sparc/elf/start.S | 111 |
2 files changed, 361 insertions, 0 deletions
diff --git a/sysdeps/sparc/dl-machine.h b/sysdeps/sparc/dl-machine.h new file mode 100644 index 0000000000..695b9d6af3 --- /dev/null +++ b/sysdeps/sparc/dl-machine.h @@ -0,0 +1,250 @@ +/* Machine-dependent ELF dynamic relocation inline functions. SPARC 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 "sparc" + +#include <assert.h> +#include <string.h> +#include <link.h> + + +/* Some SPARC opcodes we need to use for self-modifying code. */ +#define OPCODE_NOP 0x01000000 /* nop */ +#define OPCODE_CALL 0x04000000 /* call ?; add PC-rel word address */ +#define OPCODE_SETHI_G1 0x03000000 /* sethi ?, %g1; add value>>10 */ +#define OPCODE_JMP_G1 0x81c06000 /* jmp %g1+?; add lo 10 bits of value */ +#define OPCODE_SAVE_SP64 0x9de3bfc0 /* save %sp, -64, %sp */ + + +/* 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_SPARC: + 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 ("%l7"); + return got; +} + + +/* Return the run-time load address of the shared object. */ +static inline Elf32_Addr +elf_machine_load_address (void) +{ + Elf32_Addr addr; +??? + return addr; +} + +/* The `subl' insn above will contain an R_68K_RELATIVE relocation + entry intended to insert the run-time address of the label `here'. + This will be the first relocation in the text of the dynamic + linker; we skip it to avoid trying to modify read-only text in this + early stage. */ +#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \ + ((dynamic_info)[DT_RELA]->d_un.d_ptr += sizeof (Elf32_Rela), \ + (dynamic_info)[DT_RELASZ]->d_un.d_val -= sizeof (Elf32_Rela)) + +/* 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, const Elf32_Sym *sym, + Elf32_Addr (*resolve) (const Elf32_Sym **ref, + Elf32_Addr reloc_addr, + int noplt)) +{ + Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset); + Elf32_Addr loadbase; + + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_SPARC_COPY: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + memcpy (reloc_addr, (void *) (loadbase + sym->st_value), sym->st_size); + break; + case R_SPARC_GLOB_DAT: + case R_SPARC_32: + loadbase = (resolve ? (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0) : + /* RESOLVE is null during bootstrap relocation. */ + map->l_addr); + *reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend); + break; + case R_SPARC_JMP_SLOT: + loadbase = (resolve ? (*resolve) (&sym, (Elf32_Addr) reloc_addr, 1) : + /* RESOLVE is null during bootstrap relocation. */ + map->l_addr); + { + Elf32_Addr value = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend); + reloc_addr[1] = OPCODE_SETHI | (value >> 10); + reloc_addr[2] = OPCODE_JMP_G1 | (value & 0x3ff); + } + break; + case R_SPARC_8: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + *(char *) reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend); + break; + case R_SPARC_16: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + *(short *) reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend); + break; + case R_SPARC_32: + loadbase = (resolve ? (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0) : + /* RESOLVE is null during bootstrap relocation. */ + map->l_addr); + break; + case R_SPARC_RELATIVE: + *reloc_addr = map->l_addr + reloc->r_addend; + break; + case R_SPARC_DISP8: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + *(char *) reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend + - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_DISP16: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + *(short *) reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend + - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_DISP32: + loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0); + *reloc_addr = ((sym ? (loadbase + sym->st_value) : 0) + + reloc->r_addend + - (Elf32_Addr) reloc_addr); + break; + case R_SPARC_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) +{ + switch (ELF32_R_TYPE (reloc->r_info)) + { + case R_SPARC_NONE: + break; + case R_SPARC_JMP_SLOT: + break; + default: + assert (! "unexpected PLT reloc type"); + break; + } +} + +/* Nonzero iff TYPE describes relocation of a PLT entry, so + PLT entries should not be allowed to define the value. */ +#define elf_machine_pltrel_p(type) ((type) == R_SPARC_JMP_SLOT) + +/* The SPARC 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 *plt; + extern void _dl_runtime_resolve (Elf32_Word); + + if (l->l_info[DT_JMPREL] && lazy) + { + /* The entries for functions in the PLT have not yet been filled in. + Their initial contents will arrange when called to set the high 22 + bits of %g1 with an offset into the .rela.plt section and jump to + the beginning of the PLT. */ + plt = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr); + + /* The beginning of the PLT does: + + save %sp, -64, %sp + pltpc: call _dl_runtime_resolve + nop + .word MAP + + This saves the register window containing the arguments, and the + PC value (pltpc) implicitly saved in %o7 by the call points near the + location where we store the link_map pointer for this object. */ + + plt[0] = OPCODE_SAVE_SP64; /* save %sp, -64, %sp */ + /* Construct PC-relative word address. */ + plt[1] = OPCODE_CALL | (((Elf32_Addr) &_dl_runtime_resolve - + (Elf32_Addr) &plt[1]) >> 2); + plt[2] = OPCODE_NOP; /* Fill call delay slot. */ + plt[3] = l; + } + + /* 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: + | Pass two args to fixup: the PLT address computed from the PC saved + | in the PLT's call insn, and the reloc offset passed in %g1. + ld [%o7 + 8], %o1 | Second arg, loaded from PLTPC[2]. + call fixup + shrl %g1, 22, %o0 | First arg, set in delay slot of call. + | Jump to the real function. + jmpl %o0, %g0 + | In the delay slot of that jump, restore the register window + | saved by the first insn of the PLT. + restore + .size _dl_runtime_resolve, . - _dl_runtime_resolve +"); +/* The PLT uses Elf32_Rela relocs. */ +#define elf_machine_relplt elf_machine_rela +} + + +/* Mask identifying addresses reserved for the user program, + where the dynamic linker should not map anything. */ +#define ELF_MACHINE_USER_ADDRESS_MASK ??? + +/* 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 (???) diff --git a/sysdeps/sparc/elf/start.S b/sysdeps/sparc/elf/start.S new file mode 100644 index 0000000000..6dae08bafa --- /dev/null +++ b/sysdeps/sparc/elf/start.S @@ -0,0 +1,111 @@ +/* Startup code compliant to the ELF SPARC 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/SPARC ABI (NOTE: I don't actually have it) says that + when the entry point runs, most registers' values are unspecified, + except for: + + %g1 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 + .align 16 + .global _start +_start: + /* %g1 contains the address of the shared library termination + function, which we will register with `atexit' to be called by + `exit'. I suspect that on some systems, and when statically + linked, this will not be set by anything to any function + pointer; hopefully it will be zero so we don't try to call + random pointers. */ + orcc %g1, %g0, %o0 /* Move %g1 to %o0 while testing it. */ + be nofini + + /* In delay slot: clear the frame pointer. The ABI suggests this + be done, to mark the outermost frame obviously. */ + clr %fp + + /* Call atexit, argument was set in %o0 above. */ + call atexit + nop +nofini: + + /* We will use some local variables in registers below. %g1 and + the %oN registers are call-clobbered, so we can't just use them. */ +#define ARGC %l0 +#define ARGV %l1 +#define ENVP %l2 +#define TMP %l3 + + /* 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. */ + call __libc_init_first + sethi %hi(_environ), TMP /* In delay slot: prepare to use &_environ. */ + + /* Extract the arguments and environment as encoded on the stack + and save them in local variables. */ + ld [%sp + 64], ARGC /* After the register save area, ARGC. */ + add %sp, 64+4, ARGV /* Next, the ARGV elements. */ + /* After ARGC words that are the ARGV elements, and a zero word, + are the ENVP elements. Do ENVP = &ARGV[ARGC + 1]. */ + add ARGC, 1, ENVP + sll ENVP, 2, ENVP + add ARGV, ENVP, ENVP + /* Store ENVP in the global variable `_environ'. */ + st [TMP + %lo(_environ)], ENVP + + /* 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. */ + call _init + sethi %hi(_fini), TMP /* In delay slot of call. */ + or TMP, %lo(_fini), %o0 /* Argument to atexit is &_fini. */ + call atexit + nop + + /* Call the user's main function, and exit with its value. */ + mov ARGC, %o0 + mov ARGV, %o1 + call main + mov ENVP, %o2 + + call exit /* This should never return. */ + unimp 0 /* Crash if somehow it does return. */ + +/* Define a symbol for the first piece of initialized data. */ + .data + .global __data_start +__data_start: + .long 0 + .weak data_start + data_start = __data_start |