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/* Any assembly language/system dependent hacks needed to setup boot1.c so it
* will work as expected and cope with whatever platform specific wierdness is
* needed for this architecture.
* Copyright (C) 2005 by Joakim Tjernlund
*/
__asm__(
" .text\n"
" .globl _start\n"
" .type _start,@function\n"
" .hidden _start\n"
"_start:\n"
" mr 3,1\n" /* Pass SP to _dl_start in r3 */
" li 0,0\n"
" stwu 1,-16(1)\n" /* Make room on stack for _dl_start to store LR */
" stw 0,0(1)\n" /* Clear Stack frame */
" bl _dl_start@local\n" /* Perform relocation */
/* Save the address of the apps entry point in CTR register */
" mtctr 3\n" /* application entry point */
#ifdef HAVE_ASM_PPC_REL16
" bcl 20,31,1f\n"
"1: mflr 31\n"
" addis 31,31,_GLOBAL_OFFSET_TABLE_-1b@ha\n"
" addi 31,31,_GLOBAL_OFFSET_TABLE_-1b@l\n"
#else
" bl _GLOBAL_OFFSET_TABLE_-4@local\n" /* Put our GOT pointer in r31, */
" mflr 31\n"
#endif
" addi 1,1,16\n" /* Restore SP */
" lwz 7,_dl_skip_args@got(31)\n" /* load EA of _dl_skip_args */
" lwz 7,0(7)\n" /* Load word from _dl_skip_args */
" lwz 8,0(1)\n" /* Load argc from stack */
" subf 8,7,8\n" /* Subtract _dl_skip_args from argc. */
" slwi 7,7,2\n" /* Multiply by 4 */
" stwux 8,1,7\n" /* Adjust the stack pointer to skip _dl_skip_args words and store adjusted argc on stack. */
#if 0
/* Try beeing SVR4 ABI compliant?, even though it is not needed for uClibc on Linux */
/* argc */
" lwz 3,0(1)\n"
/* find argv one word offset from the stack pointer */
" addi 4,1,4\n"
/* find environment pointer (argv+argc+1) */
" lwz 5,0(1)\n"
" addi 5,5,1\n"
" rlwinm 5,5,2,0,29\n"
" add 5,5,4\n"
/* pass the auxilary vector in r6. This is passed to us just after _envp. */
"2: lwzu 0,4(6)\n"
" cmpwi 0,0\n"
" bne 2b\n"
" addi 6,6,4\n"
#endif
/* Pass a termination function pointer (in this case _dl_fini) in r3. */
/* Paulus promized he would keep r3 zero in the exec ABI. */
" lwz 3,_dl_fini@got(31)\n"
" mr 7,3\n" /* Pass _dl_fini in r7 to maintain compat */
" bctr\n" /* Jump to entry point */
" .size _start,.-_start\n"
" .previous\n"
);
/*
* 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)
/*
* Here is a macro to perform a relocation. This is only used when
* bootstrapping the dynamic loader. RELP is the relocation that we
* are performing, REL is the pointer to the address we are relocating.
* SYMBOL is the symbol involved in the relocation, and LOAD is the
* load address.
*/
#define PERFORM_BOOTSTRAP_RELOC(RELP,REL,SYMBOL,LOAD,SYMTAB) \
{int type=ELF_R_TYPE((RELP)->r_info); \
Elf32_Addr finaladdr=(SYMBOL)+(RELP)->r_addend;\
if (type==R_PPC_RELATIVE) { \
*REL=(Elf32_Word)(LOAD)+(RELP)->r_addend;\
} else if (type==R_PPC_ADDR32 || type==R_PPC_GLOB_DAT) {\
*REL=finaladdr; \
} else if (type==R_PPC_JMP_SLOT) { \
Elf32_Sword delta=finaladdr-(Elf32_Word)(REL);\
*REL=OPCODE_B(delta); \
PPC_DCBST(REL); PPC_SYNC; PPC_ICBI(REL);\
} else { \
_dl_exit(100+ELF_R_TYPE((RELP)->r_info));\
} \
}
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