diff options
| author | Max Filippov <jcmvbkbc@gmail.com> | 2015-09-16 01:49:49 +0300 |
|---|---|---|
| committer | Waldemar Brodkorb <wbx@openadk.org> | 2015-10-08 20:31:24 +0200 |
| commit | e78a0f58f23347c822c182d1c01f6eb9b9866d60 (patch) | |
| tree | 723cfbcd2411d889fb4956adb7f2d11a6d766050 /libc/sysdeps/linux/xtensa/clone.S | |
| parent | 9fae2ad9937279c9f7f40975ac14cb7b57f4a36d (diff) | |
xtensa: support call0 ABI
Most changes are mechanical replacement of 'retw' instruction with
'abi_ret' macro, defined to 'retw' or 'ret' according to ABI.
Assembly code that makes calls is duplicated for call0 ABI with changed
register numbers for parameters/return value and call instruction.
'entry' instructions are replaced with 'abi_entry' macro.
More interesting changes:
- non-leaf assembly functions (e.g. _dl_tlsdesc_dynamic,
_dl_linux_resolve, SYSCALL_ERROR_HANDLER, PSEUDO) now need to preserve
registers around intermediate calls they make, use temporary stack
frame for that;
- setjmp/longjmp only need to save and restore return address, stack
pointer and callee-saved registers in the jmpbuf;
- __clone and syscall functions had hardcoded offsets to parameter
passed on stack, on call0 ABI they don't need stack frame, so the
offset is different. Replace these offsets with FRAMESIZE macro.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'libc/sysdeps/linux/xtensa/clone.S')
| -rw-r--r-- | libc/sysdeps/linux/xtensa/clone.S | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/libc/sysdeps/linux/xtensa/clone.S b/libc/sysdeps/linux/xtensa/clone.S index 34d68a875..88cd6c1c3 100644 --- a/libc/sysdeps/linux/xtensa/clone.S +++ b/libc/sysdeps/linux/xtensa/clone.S @@ -51,7 +51,7 @@ ENTRY (__clone) mov a8, a6 /* use a8 as a temp */ mov a6, a4 mov a4, a8 - l32i a8, a1, 16 /* child_tid */ + l32i a8, a1, FRAMESIZE /* child_tid */ movi a2, SYS_ify(clone) /* syscall(NR_clone,clone_flags, usp, parent_tid, child_tls, child_tid) @@ -65,7 +65,7 @@ ENTRY (__clone) /* fall through for parent */ .Lpseudo_end: - retw + abi_ret .Leinval: movi a2, -EINVAL @@ -94,17 +94,26 @@ ENTRY (__clone) /* start child thread */ movi a0, 0 /* terminate the stack frame */ + +#if defined(__XTENSA_WINDOWED_ABI__) mov a6, a9 /* load up the 'arg' parameter */ callx4 a7 /* call the user's function */ /* Call _exit. Note that any return parameter from the user's function in a6 is seen as inputs to _exit. */ -#ifdef PIC - movi a2, _exit@PLT + movi a2, JUMPTARGET(_exit) + callx4 a2 +#elif defined(__XTENSA_CALL0_ABI__) + mov a2, a9 /* load up the 'arg' parameter */ + callx0 a7 /* call the user's function */ + + /* Call _exit. Note that any return parameter from the user's + function in a2 is seen as inputs to _exit. */ + movi a0, JUMPTARGET(_exit) + callx0 a0 #else - movi a2, _exit +#error Unsupported Xtensa ABI #endif - callx4 a2 PSEUDO_END (__clone) |