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-rw-r--r--libc/sysdeps/linux/xtensa/crt1.S81
1 files changed, 81 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/xtensa/crt1.S b/libc/sysdeps/linux/xtensa/crt1.S
index 3fa14ae58..a12f82dd6 100644
--- a/libc/sysdeps/linux/xtensa/crt1.S
+++ b/libc/sysdeps/linux/xtensa/crt1.S
@@ -35,6 +35,86 @@
#include <features.h>
+#if defined(__FDPIC__)
+
+/* This is the canonical entry point, usually the first thing in the text
+ segment. When the entry point runs, most register values are unspecified,
+ except for:
+
+ a6 Address of .dynamic section
+ a5 Interpreter map
+ a4 Executable map
+
+ a2 Contains a function pointer to be registered with `atexit'.
+ This is how the dynamic linker arranges to have DT_FINI
+ functions called for shared libraries that have been loaded
+ before this code runs.
+
+ a1 The stack (i.e., a1+16) contains the arguments and environment:
+ a1+0 argc
+ a1+4 argv[0]
+ ...
+ a1+(4*argc) NULL
+ a1+(4*(argc+1)) envp[0]
+ ...
+ NULL
+ */
+ .text
+ .align 4
+ .literal_position
+ .global _start
+ .type _start, @function
+_start:
+#if defined(__XTENSA_CALL0_ABI__)
+
+ .begin no-transform
+ call0 1f
+2:
+ .end no-transform
+ .align 4
+ .literal_position
+1:
+ movi a15, 2b
+ sub a15, a0, a15
+
+ mov a12, a4
+ mov a13, a5
+ mov a14, a6
+ mov a2, a4
+ movi a3, __ROFIXUP_LIST__
+ add a3, a3, a15
+ movi a4, __ROFIXUP_END__
+ add a4, a4, a15
+ movi a0, __self_reloc
+ add a0, a0, a15
+ callx0 a0
+
+ mov a11, a2
+ movi a2, main@GOTOFFFUNCDESC
+ add a2, a2, a11
+ l32i a3, sp, 0 /* argc */
+ addi a4, sp, 4 /* argv */
+ /* a5 is either 0 when static or set by the RTLD to the rtld_fini */
+ mov a7, a13
+ /* unused stack_end argument is what used to be argc */
+ movi a5, _init@GOTOFFFUNCDESC
+ add a5, a5, a11
+ movi a6, _fini@GOTOFFFUNCDESC
+ add a6, a6, a11
+
+ movi a0, __uClibc_main@GOTOFFFUNCDESC
+ add a0, a0, a11
+ l32i a11, a0, 4
+ l32i a0, a0, 0
+ callx0 a0
+ ill
+
+#else
+#error Unsupported Xtensa ABI
+#endif
+
+#else /* defined(__FDPIC__) */
+
#ifndef __UCLIBC_CTOR_DTOR__
.weak _init
.weak _fini
@@ -173,3 +253,4 @@ __data_start:
.long 0
.weak data_start
data_start = __data_start
+#endif /* defined(__FDPIC__) */