Commit d01869cf authored by Willy Tarreau's avatar Willy Tarreau Committed by Paul E. McKenney
Browse files

tools/nolibc: add auxiliary vector retrieval for mips 



In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 041fa97c

tools/include/nolibc/arch-mips.h

+11 −0
Original line number Diff line number Diff line
@@ -177,6 +177,7 @@ struct sys_stat_struct { 
})



char **environ __attribute__((weak));

const unsigned long *_auxv __attribute__((weak));



/* startup code, note that it's called __start on MIPS */

void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void)
@@ -196,6 +197,16 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void) 
		"lui $a3, %hi(environ)\n"     // load environ into a3 (hi)

		"addiu $a3, %lo(environ)\n"   // load environ into a3 (lo)

		"sw $a2,($a3)\n"              // store envp(a2) into environ



		"move $t0, $a2\n"             // iterate t0 over envp, look for NULL

		"0:"                          // do {

		"lw $a3, ($t0)\n"             //   a3=*(t0);

		"bne $a3, $0, 0b\n"           // } while (a3);

		"addiu $t0, $t0, 4\n"         // delayed slot: t0+=4;

		"lui $a3, %hi(_auxv)\n"       // load _auxv into a3 (hi)

		"addiu $a3, %lo(_auxv)\n"     // load _auxv into a3 (lo)

		"sw $t0, ($a3)\n"             // store t0 into _auxv



		"li $t0, -8\n"

		"and $sp, $sp, $t0\n"   // sp must be 8-byte aligned

		"addiu $sp,$sp,-16\n"   // the callee expects to save a0..a3 there!