Commit 241c4b4e authored by Sven Schnelle's avatar Sven Schnelle Committed by Paul E. McKenney
Browse files

tools/nolibc: add auxiliary vector retrieval for s390 



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 avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent d01869cf

tools/include/nolibc/arch-s390.h

+10 −0
Original line number Diff line number Diff line
@@ -160,6 +160,7 @@ struct sys_stat_struct { 
})



char **environ __attribute__((weak));

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



/* startup code */

void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
@@ -179,6 +180,15 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void) 
		"larl	%r1,environ\n"

		"stg	%r4,0(%r1)\n"



		/* search for auxv */

		"lgr	%r5,%r4\n"		/* start at envp */

		"1:\n"

		"clg	%r0,0(%r5)\n"		/* entry zero? */

		"la	%r5,8(%r5)\n"		/* advance pointer */

		"jnz	1b\n"			/* no -> test next pointer */

		"larl	%r1,_auxv\n"		/* yes -> store value in _auxv */

		"stg	%r5,0(%r1)\n"



		"aghi	%r15,-160\n"		/* allocate new stackframe */

		"xc	0(8,%r15),0(%r15)\n"	/* clear backchain */

		"brasl	%r14,main\n"		/* ret value of main is arg to exit */