csu: Implement _start using as to satisfy unwinders on aarch64

The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Address register is defined in the virtual unwind table,
and its rule is undefined (for example, by DW_CFA_undefined), then
there is no return address and no call address, and the virtual
unwind of stack activations is complete.

Reviewed by:
Differential Revision:	https://reviews.freebsd.org/D40623

1 files changed, 0 insertions, 15 deletions

diff --git a/lib/csu/aarch64/crt1_c.c b/lib/csu/aarch64/crt1_c.c
index 7f4fea37ba1a..095c798046b4 100644
--- a/lib/csu/aarch64/crt1_c.c
+++ b/lib/csu/aarch64/crt1_c.c
@@ -32,19 +32,4 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include "libc_private.h"
 #include "csu_common.h"
-
-void __start(int, char **, char **, void (*)(void)) __dead2;
-
-/* The entry function. */
-void
-__start(int argc, char *argv[], char *env[], void (*cleanup)(void))
-{
-#ifdef GCRT
-	__libc_start1_gcrt(argc, argv, env, cleanup, main, &eprol, &etext);
-__asm__("eprol:");
-#else
-	__libc_start1(argc, argv, env, cleanup, main);
-#endif
-}