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-rw-r--r--sysdeps/arm/elf/start.S81
1 files changed, 24 insertions, 57 deletions
diff --git a/sysdeps/arm/elf/start.S b/sysdeps/arm/elf/start.S
index e0964a1e38..13b9c780ef 100644
--- a/sysdeps/arm/elf/start.S
+++ b/sysdeps/arm/elf/start.S
@@ -24,19 +24,19 @@
This includes _init and _libc_init
- At this entry point, most registers' values are unspecified, except for:
+ At this entry point, most registers' values are unspecified, except:
- r0 Contains a function pointer to be registered with `atexit'.
+ a1 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.
sp The stack contains the arguments and environment:
- 0(%esp) argc
- 4(%esp) argv[0]
+ 0(sp) argc
+ 4(sp) argv[0]
...
- (4*argc)(%esp) NULL
- (4*(argc+1))(%esp) envp[0]
+ (4*argc)(sp) NULL
+ (4*(argc+1))(sp) envp[0]
...
NULL
*/
@@ -44,62 +44,29 @@
.text
.globl _start
_start:
- /* Clear the frame pointer. The Intel ABI suggests this be done,
- to mark the outermost frame obviously. This seems like a
- sensible thing to do */
+ /* Clear the frame pointer since this is the outermost frame. */
mov fp, #0
- /* r0 contains the address of the shared library termination
- function, which we will register with `atexit' to be called by
- `exit'. I suspect that on some systems, and when statically
- linked, this will not be set by anything to any function
- pointer; hopefully it will be zero so we don't try to call
- random pointers. */
- cmp r0,#0
- blne atexit(PLT)
-
- /* Do essential libc initialization. In statically linked
- programs under the GNU Hurd, this is what sets up the
- arguments on the stack for the code below. For dyn-link
- programs, this has been run already, in the .init code. */
-#ifndef PIC
- bl __libc_init_first
-
- /* Extract the arguments and environment as encoded on the stack
- and set up the arguments for `main': argc, argv, envp. */
- ldr r0,[sp]
- add r1,sp,#4
- add r2,r1,r0,lsl #2
- add r2,r2,#4
- /* save a copy of envp while we have it */
- ldr r3,L_environ
- str r2,[r3]
-
- /* Call `_init', which is the entry point to our own `.init'
- section; and register with `atexit' to have `exit' call
- `_fini', which is the entry point to our own `.fini' section. */
- bl _init
- ldr r0,L_fini
- bl atexit
- b L_pfini
-
-L_fini: .word _fini
-L_environ: .word _environ
-L_pfini:
-#endif
- /* rebuild the arg list for main() */
- ldr r0,[sp]
- add r1,sp,#4
- add r2,r1,r0,lsl #2
- add r2,r2,#4
-
- /* Call the user's main function, and exit with its value. */
- bl main
- bl exit
+ /* Pop argc off the stack and save a pointer to argv */
+ ldmfd sp!, {a2}
+ mov a3, sp
+
+ /* Push the last arguments to main() onto the stack */
+ stmfd sp!, {a1}
+ ldr a1, =_fini
+ stmfd sp!, {a1}
+
+ /* Set up the other arguments for main() that go in registers */
+ ldr a1, =main
+ ldr a4, =_init
+
+ /* __libc_start_main (main, argc, argv, init, fini, rtld_fini) */
+
+ /* Let the libc call main and exit with its return code. */
+ bl __libc_start_main
/* should never get here....*/
bl abort
-
/* Define a symbol for the first piece of initialized data. */
.data
.globl __data_start