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authorMax Filippov <jcmvbkbc@gmail.com>2015-09-16 01:49:49 +0300
committerWaldemar Brodkorb <wbx@openadk.org>2015-10-08 20:31:24 +0200
commite78a0f58f23347c822c182d1c01f6eb9b9866d60 (patch)
tree723cfbcd2411d889fb4956adb7f2d11a6d766050 /libc/sysdeps/linux
parent9fae2ad9937279c9f7f40975ac14cb7b57f4a36d (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')
-rw-r--r--libc/sysdeps/linux/xtensa/__longjmp.S17
-rw-r--r--libc/sysdeps/linux/xtensa/bits/setjmp.h9
-rw-r--r--libc/sysdeps/linux/xtensa/clone.S21
-rw-r--r--libc/sysdeps/linux/xtensa/crt1.S30
-rw-r--r--libc/sysdeps/linux/xtensa/crti.S15
-rw-r--r--libc/sysdeps/linux/xtensa/crtn.S17
-rw-r--r--libc/sysdeps/linux/xtensa/mmap.S2
-rw-r--r--libc/sysdeps/linux/xtensa/setjmp.S17
-rw-r--r--libc/sysdeps/linux/xtensa/syscall.S4
-rw-r--r--libc/sysdeps/linux/xtensa/sysdep.h45
-rw-r--r--libc/sysdeps/linux/xtensa/vfork.S23
-rw-r--r--libc/sysdeps/linux/xtensa/windowspill.S3
12 files changed, 188 insertions, 15 deletions
diff --git a/libc/sysdeps/linux/xtensa/__longjmp.S b/libc/sysdeps/linux/xtensa/__longjmp.S
index 4d55906db..acc0b4ff2 100644
--- a/libc/sysdeps/linux/xtensa/__longjmp.S
+++ b/libc/sysdeps/linux/xtensa/__longjmp.S
@@ -48,6 +48,7 @@
ENTRY (__longjmp)
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Invalidate all but the current window. Reading and writing
special registers WINDOWBASE and WINDOWSTART are
privileged operations, so user processes must call the
@@ -120,6 +121,22 @@ ENTRY (__longjmp)
movnez a2, a3, a3
retw
+#elif defined(__XTENSA_CALL0_ABI__)
+ l32i a0, a2, 0
+ l32i a1, a2, 4
+ l32i a12, a2, 8
+ l32i a13, a2, 12
+ l32i a14, a2, 16
+ l32i a15, a2, 20
+
+ /* Return v ? v : 1. */
+ movi a2, 1
+ movnez a2, a3, a3
+
+ ret
+#else
+#error Unsupported Xtensa ABI
+#endif
END (__longjmp)
libc_hidden_def (__longjmp)
diff --git a/libc/sysdeps/linux/xtensa/bits/setjmp.h b/libc/sysdeps/linux/xtensa/bits/setjmp.h
index 183fa3e64..5d3e5509e 100644
--- a/libc/sysdeps/linux/xtensa/bits/setjmp.h
+++ b/libc/sysdeps/linux/xtensa/bits/setjmp.h
@@ -23,6 +23,7 @@
# error "Never include <bits/setjmp.h> directly; use <setjmp.h> instead."
#endif
+#if defined(__XTENSA_WINDOWED_ABI__)
/* The jmp_buf structure for Xtensa holds the following (where "proc"
is the procedure that calls setjmp): 4-12 registers from the window
of proc, the 4 words from the save area at proc's $sp (in case a
@@ -30,5 +31,13 @@
proc. Everything else is saved on the stack in the normal save areas. */
typedef int __jmp_buf[17];
+#elif defined(__XTENSA_CALL0_ABI__)
+/* The jmp_buf structure for Xtensa Call0 ABI holds the return address,
+ the stack pointer and callee-saved registers (a12 - a15). */
+
+typedef int __jmp_buf[6];
+#else
+#error Unsupported Xtensa ABI
+#endif
#endif /* bits/setjmp.h */
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)
diff --git a/libc/sysdeps/linux/xtensa/crt1.S b/libc/sysdeps/linux/xtensa/crt1.S
index 025ebd070..efbe264c0 100644
--- a/libc/sysdeps/linux/xtensa/crt1.S
+++ b/libc/sysdeps/linux/xtensa/crt1.S
@@ -76,6 +76,7 @@
.global _start
.type _start, @function
_start:
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Clear a0 to obviously mark the outermost frame. */
movi a0, 0
@@ -104,6 +105,35 @@ _start:
But let the libc call main. */
movi a4, __uClibc_main
callx4 a4
+#elif defined(__XTENSA_CALL0_ABI__)
+ /* Setup the shared library termination function. */
+ mov a7, a2
+
+ /* Load up the user's main function. */
+ movi a2, main
+
+ /* Extract the arguments as encoded on the stack and set up
+ the arguments for `main': argc, argv. envp will be determined
+ later in __uClibc_main. */
+ l32i a3, a1, 0 /* Load the argument count. */
+ addi a4, a1, 4 /* Compute the argv pointer. */
+
+ /* Push address of our own entry points to .fini and .init. */
+ movi a5, _init
+ movi a6, _fini
+
+ /* Provide the highest stack address to the user code (for stacks
+ which grow downwards). Note that we destroy the stack version
+ of argc here. */
+ s32i a1, a1, 0
+
+ /* Call the user's main function, and exit with its value.
+ But let the libc call main. */
+ movi a0, __uClibc_main
+ callx0 a0
+#else
+#error Unsupported Xtensa ABI
+#endif
/* Crash if somehow `exit' does return. */
ill
diff --git a/libc/sysdeps/linux/xtensa/crti.S b/libc/sysdeps/linux/xtensa/crti.S
index a01c02c9f..ba804eb45 100644
--- a/libc/sysdeps/linux/xtensa/crti.S
+++ b/libc/sysdeps/linux/xtensa/crti.S
@@ -5,12 +5,25 @@
.global _init
.type _init, @function
_init:
+#if defined(__XTENSA_WINDOWED_ABI__)
entry sp, 48
-
+#elif defined(__XTENSA_CALL0_ABI__)
+ addi sp, sp, -16
+ s32i a0, sp, 0
+#else
+#error Unsupported Xtensa ABI
+#endif
.section .fini
.align 4
.global _fini
.type _fini, @function
_fini:
+#if defined(__XTENSA_WINDOWED_ABI__)
entry sp, 48
+#elif defined(__XTENSA_CALL0_ABI__)
+ addi sp, sp, -16
+ s32i a0, sp, 0
+#else
+#error Unsupported Xtensa ABI
+#endif
diff --git a/libc/sysdeps/linux/xtensa/crtn.S b/libc/sysdeps/linux/xtensa/crtn.S
index ab1a489c5..a3598da1a 100644
--- a/libc/sysdeps/linux/xtensa/crtn.S
+++ b/libc/sysdeps/linux/xtensa/crtn.S
@@ -1,8 +1,23 @@
/* glibc's sysdeps/xtensa/elf/initfini.c used for reference [EPILOG] */
.section .init
+#if defined(__XTENSA_WINDOWED_ABI__)
retw
-
+#elif defined(__XTENSA_CALL0_ABI__)
+ l32i a0, sp, 0
+ addi sp, sp, 16
+ ret
+#else
+#error Unsupported Xtensa ABI
+#endif
.section .fini
+#if defined(__XTENSA_WINDOWED_ABI__)
retw
+#elif defined(__XTENSA_CALL0_ABI__)
+ l32i a0, sp, 0
+ addi sp, sp, 16
+ ret
+#else
+#error Unsupported Xtensa ABI
+#endif
diff --git a/libc/sysdeps/linux/xtensa/mmap.S b/libc/sysdeps/linux/xtensa/mmap.S
index c05036aae..b4dd7c53b 100644
--- a/libc/sysdeps/linux/xtensa/mmap.S
+++ b/libc/sysdeps/linux/xtensa/mmap.S
@@ -48,7 +48,7 @@ ENTRY (__mmap)
bltz a2, SYSCALL_ERROR_LABEL
.Lpseudo_end:
- retw
+ abi_ret
PSEUDO_END (__mmap)
diff --git a/libc/sysdeps/linux/xtensa/setjmp.S b/libc/sysdeps/linux/xtensa/setjmp.S
index bf4691294..862bf6729 100644
--- a/libc/sysdeps/linux/xtensa/setjmp.S
+++ b/libc/sysdeps/linux/xtensa/setjmp.S
@@ -88,6 +88,7 @@ END (setjmp)
ENTRY (__sigsetjmp)
1:
+#if defined(__XTENSA_WINDOWED_ABI__)
/* Flush registers. */
movi a4, __window_spill
callx4 a4
@@ -146,6 +147,22 @@ ENTRY (__sigsetjmp)
callx4 a3
mov a2, a6
retw
+#elif defined(__XTENSA_CALL0_ABI__)
+ s32i a0, a2, 0
+ s32i a1, a2, 4
+ s32i a12, a2, 8
+ s32i a13, a2, 12
+ s32i a14, a2, 16
+ s32i a15, a2, 20
+ mov a12, a2
+ movi a0, __sigjmp_save
+ callx0 a0
+ l32i a0, a12, 0
+ l32i a12, a12, 8
+ ret
+#else
+#error Unsupported Xtensa ABI
+#endif
END(__sigsetjmp)
weak_extern(_setjmp)
diff --git a/libc/sysdeps/linux/xtensa/syscall.S b/libc/sysdeps/linux/xtensa/syscall.S
index 0e1a5d0be..790a8d018 100644
--- a/libc/sysdeps/linux/xtensa/syscall.S
+++ b/libc/sysdeps/linux/xtensa/syscall.S
@@ -26,7 +26,7 @@
*/
ENTRY (syscall)
- l32i a9, a1, 16 /* load extra argument from stack */
+ l32i a9, a1, FRAMESIZE/* load extra argument from stack */
mov a8, a7
mov a7, a3 /* preserve a3 in a7 */
mov a3, a4
@@ -37,5 +37,5 @@ ENTRY (syscall)
movi a4, -4095
bgeu a2, a4, SYSCALL_ERROR_LABEL
.Lpseudo_end:
- retw
+ abi_ret
PSEUDO_END (syscall)
diff --git a/libc/sysdeps/linux/xtensa/sysdep.h b/libc/sysdeps/linux/xtensa/sysdep.h
index 4873a413d..ce2b0a0d6 100644
--- a/libc/sysdeps/linux/xtensa/sysdep.h
+++ b/libc/sysdeps/linux/xtensa/sysdep.h
@@ -28,13 +28,24 @@
#define ASM_TYPE_DIRECTIVE(name, typearg) .type name, typearg
#define ASM_SIZE_DIRECTIVE(name) .size name, . - name
+#if defined(__XTENSA_WINDOWED_ABI__)
+#define abi_entry(reg, frame_size) entry reg, frame_size
+#define abi_ret retw
+#elif defined(__XTENSA_CALL0_ABI__)
+#define abi_entry(reg, frame_size)
+#define abi_ret ret
+#else
+#error Unsupported Xtensa ABI
+#endif
+
+
#define ENTRY(name) \
ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name), @function); \
.align ALIGNARG(2); \
LITERAL_POSITION; \
C_LABEL(name) \
- entry sp, FRAMESIZE; \
+ abi_entry(sp, FRAMESIZE); \
CALL_MCOUNT
#define HIDDEN_ENTRY(name) \
@@ -44,7 +55,7 @@
.align ALIGNARG(2); \
LITERAL_POSITION; \
C_LABEL(name) \
- entry sp, FRAMESIZE; \
+ abi_entry(sp, FRAMESIZE); \
CALL_MCOUNT
#undef END
@@ -73,7 +84,13 @@
#endif
#ifndef FRAMESIZE
+#if defined(__XTENSA_WINDOWED_ABI__)
#define FRAMESIZE 16
+#elif defined(__XTENSA_CALL0_ABI__)
+#define FRAMESIZE 0
+#else
+#error Unsupported Xtensa ABI
+#endif
#endif
#define CALL_MCOUNT /* Do nothing. */
@@ -118,7 +135,7 @@
END (name)
#undef ret_NOERRNO
-#define ret_NOERRNO retw
+#define ret_NOERRNO abi_ret
/* The function has to return the error code. */
#undef PSEUDO_ERRVAL
@@ -133,7 +150,7 @@
END (name)
#undef ret_ERRVAL
-#define ret_ERRVAL retw
+#define ret_ERRVAL abi_ret
#if defined _LIBC_REENTRANT
# if defined USE___THREAD
@@ -151,6 +168,8 @@
movi a2, -1; \
j .Lpseudo_end;
# else /* !USE___THREAD */
+
+#if defined(__XTENSA_WINDOWED_ABI__)
# define SYSCALL_ERROR_HANDLER \
0: neg a2, a2; \
mov a6, a2; \
@@ -159,6 +178,24 @@
s32i a2, a6, 0; \
movi a2, -1; \
j .Lpseudo_end;
+#elif defined(__XTENSA_CALL0_ABI__)
+# define SYSCALL_ERROR_HANDLER \
+0: neg a2, a2; \
+ addi a1, a1, -16; \
+ s32i a0, a1, 0; \
+ s32i a2, a1, 4; \
+ movi a0, __errno_location@PLT; \
+ callx0 a0; \
+ l32i a0, a1, 0; \
+ l32i a3, a1, 4; \
+ addi a1, a1, 16; \
+ s32i a3, a2, 0; \
+ movi a2, -1; \
+ j .Lpseudo_end;
+#else
+#error Unsupported Xtensa ABI
+#endif
+
# endif /* !USE___THREAD */
#else /* !_LIBC_REENTRANT */
#define SYSCALL_ERROR_HANDLER \
diff --git a/libc/sysdeps/linux/xtensa/vfork.S b/libc/sysdeps/linux/xtensa/vfork.S
index 6aced0a50..b8db5c1a1 100644
--- a/libc/sysdeps/linux/xtensa/vfork.S
+++ b/libc/sysdeps/linux/xtensa/vfork.S
@@ -51,6 +51,8 @@
HIDDEN_ENTRY (__vfork)
+
+#if defined(__XTENSA_WINDOWED_ABI__)
.literal .Ljumptable, 0, .L4, .L8, .L12
mov a3, a0 # move return address out of the way
@@ -163,6 +165,27 @@ HIDDEN_ENTRY (__vfork)
PSEUDO_END (__vfork)
.Lpseudo_end:
retw
+#elif defined(__XTENSA_CALL0_ABI__)
+ SAVE_PID(a5, a8, a3, a4)
+
+ /* Use syscall 'clone'. Set new stack pointer to the same address. */
+ movi a2, SYS_ify (clone)
+ movi a3, 0
+ movi a6, CLONE_VM | CLONE_VFORK | SIGCHLD
+ syscall
+
+ RESTORE_PID(a5, a8, a2)
+
+ movi a3, -4096
+ bgeu a2, a3, 1f
+ ret
+1:
+ PSEUDO_END (__vfork)
+.Lpseudo_end:
+ ret
+#else
+#error Unsupported Xtensa ABI
+#endif
weak_alias (__vfork, vfork)
libc_hidden_def(vfork)
diff --git a/libc/sysdeps/linux/xtensa/windowspill.S b/libc/sysdeps/linux/xtensa/windowspill.S
index 4167b2877..013025648 100644
--- a/libc/sysdeps/linux/xtensa/windowspill.S
+++ b/libc/sysdeps/linux/xtensa/windowspill.S
@@ -18,6 +18,7 @@
#include <bits/xtensa-config.h>
+#ifdef __XTENSA_WINDOWED_ABI__
.text
.align 4
.literal_position
@@ -93,3 +94,5 @@ __window_spill:
#endif
#endif
retw
+
+#endif