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- /*
- * Architecture specific code used by dl-startup.c
- * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
- *
- * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
- */
- #include <features.h>
- #include <bits/arm_bx.h>
- #if defined(__FDPIC__)
- #if !defined(__thumb__) || defined(__thumb2__)
- __asm__(
- " .text\n"
- " .globl _start\n"
- " .type _start,%function\n"
- #if defined(__thumb2__)
- " .thumb_func\n"
- #endif
- " .align 2\n"
- "_start:\n"
- /* We compute the parameters for __self_reloc:
- - r0 is a pointer to the loadmap (either from r8 or r7 if rtld is
- lauched in standalone mode)
- - r1 is a pointer to the start of .rofixup section
- - r2 is a pointer to the last word of .rofixup section
- __self_reloc will fix indirect addresses in .rofixup
- section and will return the relocated GOT value.
- */
- #if defined(__thumb2__)
- " sub r4, pc, #4\n"
- #else
- " sub r4, pc, #8\n"
- #endif
- " ldr r1, .L__ROFIXUP_LIST__\n"
- " add r1, r1, r4\n"
- " ldr r2, .L__ROFIXUP_END__\n"
- " add r2, r2, r4\n"
- " movs r0, r8\n"
- " it eq\n"
- " moveq r0, r7\n"
- " push {r7, r8, r9, r10}\n"
- " bl __self_reloc;\n"
- " pop {r7, r8, r9, r10}\n"
- /* We compute the parameters for dl_start(). See DL_START()
- macro below. The address of the user entry point is
- returned in dl_main_funcdesc (on stack). */
- " mov r1, r7\n"
- " mov r2, r8\n"
- " mov r3, r9\n"
- " mov r4, sp\n"
- " sub r5, sp, #8\n"
- " sub sp, sp, #16\n"
- " str r4, [sp, #4]\n"
- " str r5, [sp, #0]\n"
- " mov r9, r0\n"
- /* Save r9 into r4, to preserve the GOT pointer. */
- " mov r4, r9\n"
- " bl _dl_start;\n"
- /* Now compute parameters for entry point according to FDPIC ABI. */
- " ldr r10, .L_dl_fini_gotofffuncdesc\n"
- /* Save GOT value from r4. */
- " add r10, r10, r4\n"
- " ldr r5, [sp, #8]\n"
- " ldr r9, [sp, #12]\n"
- " add sp, sp, #16\n"
- " bx r5\n"
- ".loopforever:\n"
- " b .loopforever\n"
- ".L__ROFIXUP_LIST__:\n"
- " .word __ROFIXUP_LIST__ - _start\n"
- ".L__ROFIXUP_END__:\n"
- " .word __ROFIXUP_END__ - _start\n"
- ".L_dl_fini_gotofffuncdesc:\n"
- " .word _dl_fini(GOTOFFFUNCDESC)\n"
- " .size _start,.-_start\n"
- " .previous\n"
- );
- #else /* !defined(__thumb__) */
- #error Thumb-1 is not supported
- #endif /* !defined(__thumb__) */
- #else /* defined(__FDPIC__) */
- #if !defined(__thumb__)
- __asm__(
- " .text\n"
- " .globl _start\n"
- " .type _start,%function\n"
- " .hidden _start\n"
- "_start:\n"
- " @ at start time, all the args are on the stack\n"
- " mov r0, sp\n"
- " bl _dl_start\n"
- " @ returns user entry point in r0\n"
- " mov r6, r0\n"
- " @ we are PIC code, so get global offset table\n"
- " ldr sl, .L_GET_GOT\n"
- " add sl, pc, sl\n"
- ".L_GOT_GOT:\n"
- " @ See if we were run as a command with the executable file\n"
- " @ name as an extra leading argument.\n"
- " ldr r4, .L_SKIP_ARGS\n"
- " ldr r4, [sl, r4]\n"
- " @ get the original arg count\n"
- " ldr r1, [sp]\n"
- " @ subtract _dl_skip_args from it\n"
- " sub r1, r1, r4\n"
- " @ adjust the stack pointer to skip them\n"
- " add sp, sp, r4, lsl #2\n"
- " @ get the argv address\n"
- " add r2, sp, #4\n"
- " @ store the new argc in the new stack location\n"
- " str r1, [sp]\n"
- " @ compute envp\n"
- " add r3, r2, r1, lsl #2\n"
- " add r3, r3, #4\n"
- "\n\n"
- " @ load the finalizer function\n"
- " ldr r0, .L_FINI_PROC\n"
- " ldr r0, [sl, r0]\n"
- " @ jump to the user_s entry point\n"
- " " __stringify(BX(r6)) "\n"
- ".L_GET_GOT:\n"
- " .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n"
- ".L_SKIP_ARGS:\n"
- " .word _dl_skip_args(GOTOFF)\n"
- ".L_FINI_PROC:\n"
- " .word _dl_fini(GOT)\n"
- "\n\n"
- " .size _start,.-_start\n"
- ".previous\n"
- );
- #else
- __asm__(
- " .text\n"
- " .arm\n"
- " .globl _start\n"
- " .type _start,%function\n"
- "_start:\n"
- " @ dumb: can't persuade the linker to make the start address\n"
- " @ odd, so use an arm function and change to thumb (_dl_start\n"
- " @ is thumb)\n"
- " adr r0, __dl_thumb_start+1\n"
- " bx r0\n"
- "\n\n"
- " .thumb\n"
- " .globl __dl_thumb_start\n"
- " .thumb_func\n"
- " .type __dl_thumb_start,%function\n"
- "__dl_thumb_start:\n"
- " @ at start time, all the args are on the stack\n"
- " mov r0, sp\n"
- " bl _dl_start\n"
- " @ returns user entry point in r0\n"
- " mov r6, r0\n"
- " @ we are PIC code, so get global offset table\n"
- " ldr r7, .L_GET_GOT\n"
- ".L_GOT_GOT:\n"
- " add r7, pc\n"
- " @ See if we were run as a command with the executable file\n"
- " @ name as an extra leading argument.\n"
- " ldr r4, .L_SKIP_ARGS\n"
- " ldr r4, [r7, r4]\n"
- " @ get the original arg count\n"
- " ldr r1, [sp]\n"
- " @ subtract _dl_skip_args from it\n"
- " sub r1, r1, r4\n"
- " @ adjust the stack pointer to skip them\n"
- " lsl r4, r4, #2\n"
- " add sp, r4\n"
- " @ get the argv address\n"
- " add r2, sp, #4\n"
- " @ store the new argc in the new stack location\n"
- " str r1, [sp]\n"
- " @ compute envp\n"
- " lsl r3, r1, #2\n"
- " add r3, r3, r2\n"
- " add r3, #4\n"
- "\n\n"
- " @ load the finalizer function\n"
- " ldr r0, .L_FINI_PROC\n"
- " ldr r0, [r7, r0]\n"
- " @ jump to the user_s entry point\n"
- " " __stringify(BX(r6)) "\n"
- "\n\n"
- ".L_GET_GOT:\n"
- " .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n"
- ".L_SKIP_ARGS:\n"
- " .word _dl_skip_args(GOTOFF)\n"
- ".L_FINI_PROC:\n"
- " .word _dl_fini(GOT)\n"
- "\n\n"
- " .size _start,.-_start\n"
- ".previous\n"
- );
- #endif
- #endif /* defined(__FDPIC__) */
- /* Get a pointer to the argv array. On many platforms this can be just
- * the address of 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)+1)
- /* Handle relocation of the symbols in the dynamic loader. */
- static __always_inline
- void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr,
- unsigned long symbol_addr, DL_LOADADDR_TYPE load_addr, Elf32_Sym *symtab)
- {
- switch (ELF_R_TYPE(rpnt->r_info)) {
- case R_ARM_NONE:
- break;
- case R_ARM_ABS32:
- *reloc_addr += symbol_addr;
- break;
- case R_ARM_PC24:
- {
- unsigned long addend;
- long newvalue, topbits;
- addend = *reloc_addr & 0x00ffffff;
- if (addend & 0x00800000) addend |= 0xff000000;
- newvalue = symbol_addr - (unsigned long)reloc_addr + (addend << 2);
- topbits = newvalue & 0xfe000000;
- if (topbits != 0xfe000000 && topbits != 0x00000000)
- {
- #if 0
- /* Don't bother with this during ldso initilization... */
- newvalue = fix_bad_pc24(reloc_addr, symbol_addr)
- - (unsigned long)reloc_addr + (addend << 2);
- topbits = newvalue & 0xfe000000;
- if (unlikely(topbits != 0xfe000000 && topbits != 0x00000000))
- {
- SEND_STDERR("R_ARM_PC24 relocation out of range\n");
- _dl_exit(1);
- }
- #else
- SEND_STDERR("R_ARM_PC24 relocation out of range\n");
- _dl_exit(1);
- #endif
- }
- newvalue >>= 2;
- symbol_addr = (*reloc_addr & 0xff000000) | (newvalue & 0x00ffffff);
- *reloc_addr = symbol_addr;
- break;
- }
- case R_ARM_GLOB_DAT:
- case R_ARM_JUMP_SLOT:
- *reloc_addr = symbol_addr;
- break;
- case R_ARM_RELATIVE:
- *reloc_addr = DL_RELOC_ADDR(load_addr, *reloc_addr);
- break;
- case R_ARM_COPY:
- break;
- #ifdef __FDPIC__
- case R_ARM_FUNCDESC_VALUE:
- {
- struct funcdesc_value *dst = (struct funcdesc_value *) reloc_addr;
- dst->entry_point += symbol_addr;
- dst->got_value = load_addr.got_value;
- }
- break;
- #endif
- default:
- SEND_STDERR("Unsupported relocation type\n");
- _dl_exit(1);
- }
- }
- #ifdef __FDPIC__
- #undef DL_START
- #define DL_START(X) \
- static void __attribute__ ((used)) \
- _dl_start (Elf32_Addr dl_boot_got_pointer, \
- struct elf32_fdpic_loadmap *dl_boot_progmap, \
- struct elf32_fdpic_loadmap *dl_boot_ldsomap, \
- Elf32_Dyn *dl_boot_ldso_dyn_pointer, \
- struct funcdesc_value *dl_main_funcdesc, \
- X)
- /*
- * Transfer control to the user's application, once the dynamic loader
- * is done. We return the address of the function's entry point to
- * _dl_boot, see boot1_arch.h.
- */
- #define START() do { \
- struct elf_resolve *exec_mod = _dl_loaded_modules; \
- dl_main_funcdesc->entry_point = _dl_elf_main; \
- while (exec_mod->libtype != elf_executable) \
- exec_mod = exec_mod->next; \
- dl_main_funcdesc->got_value = exec_mod->loadaddr.got_value; \
- return; \
- } while (0)
- /* We use __aeabi_idiv0 in _dl_find_hash, so we need to have the raise
- symbol. */
- int raise(int sig)
- {
- _dl_exit(1);
- }
- #endif /* __FDPIC__ */
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