a2=argv[0]
a3=argv[argc+1]
-This file now uses the register naming from the ARM Procedure Calling Standard
-
- Name Number APCS Role
-
- a1 0 argument 1 / integer result / scratch register / argc
- a2 1 argument 2 / scratch register / argv
- a3 2 argument 3 / scratch register / envp
- a4 3 argument 4 / scratch register
- v1 4 register variable
- v2 5 register variable
- v3 6 register variable
- v4 7 register variable
- v5 8 register variable
- sb/v6 9 static base / register variable
- sl/v7 10 stack limit / stack chunk handle / reg. variable
- fp 11 frame pointer
- ip 12 scratch register / new-sb in inter-link-unit calls
- sp 13 lower end of current stack frame
- lr 14 link address / scratch register
- pc 15 program counter
+ARM register quick reference:
+
+ Name Number ARM Procedure Calling Standard Role
+
+ a1 r0 argument 1 / integer result / scratch register / argc
+ a2 r1 argument 2 / scratch register / argv
+ a3 r2 argument 3 / scratch register / envp
+ a4 r3 argument 4 / scratch register
+ v1 r4 register variable
+ v2 r5 register variable
+ v3 r6 register variable
+ v4 r7 register variable
+ v5 r8 register variable
+ sb/v6 r9 static base / register variable
+ sl/v7 r10 stack limit / stack chunk handle / reg. variable
+ fp r11 frame pointer
+ ip r12 scratch register / new-sb in inter-link-unit calls
+ sp r13 lower end of current stack frame
+ lr r14 link address / scratch register
+ pc r15 program counter
*/
.text
- .align 2
- .global __environ
.global _start
- .global exit
- .global main
+ .global __uClibc_main
.type _start,%function
- .type exit,%function
- .type main,%function
+ .type __uClibc_main,%function
.text
_start:
/* clear the frame pointer */
mov fp, #0
- /* Load register a1 (argc) from the stack to its final resting place */
- ldr a1, [sp], #4
-
- /* Copy argv pointer into a2 -- which its final resting place */
- mov a2, sp
-
- /* Set up environ, skip to the end of argv, and put
- * a pointer to whatever we find there (hopefully the
- environment) in a3 */
- ldr a4, .L3
- add a3, a2, a1, lsl #2
- add a3, a3, #4
- str a3, [a4, #0]
+ /* Load register r0 (argc) from the stack to its final resting place */
+ ldr r0, [sp], #4
- bl main
- bl exit
+ /* Copy argv pointer into r1 -- which its final resting place */
+ mov r1, sp
-.align 2
-.L3:
- .word __environ
-
-
-.data
- .align 2
- .global __environ
-
-__environ:
- .long 0
+ /* Skip to the end of argv and put a pointer to whatever
+ we find there (hopefully the environment) in a3 */
+ add r2, r1, r0, lsl #2
+ add r2, r2, #4
-.weak environ
-environ = __environ
+ /* Ok, now run uClibc's main() -- shouldn't return */
+ bl __uClibc_main
ARM register quick reference:
- Name Number APCS Role
-
- a1 0 argument 1 / integer result / scratch register / argc
- a2 1 argument 2 / scratch register / argv
- a3 2 argument 3 / scratch register / envp
- a4 3 argument 4 / scratch register
- v1 4 register variable
- v2 5 register variable
- v3 6 register variable
- v4 7 register variable
- v5 8 register variable
- sb/v6 9 static base / register variable
- sl/v7 10 stack limit / stack chunk handle / reg. variable
- fp 11 frame pointer
- ip 12 scratch register / new-sb in inter-link-unit calls
- sp 13 lower end of current stack frame
- lr 14 link address / scratch register
- pc 15 program counter
+ Name Number ARM Procedure Calling Standard Role
+
+ a1 r0 argument 1 / integer result / scratch register / argc
+ a2 r1 argument 2 / scratch register / argv
+ a3 r2 argument 3 / scratch register / envp
+ a4 r3 argument 4 / scratch register
+ v1 r4 register variable
+ v2 r5 register variable
+ v3 r6 register variable
+ v4 r7 register variable
+ v5 r8 register variable
+ sb/v6 r9 static base / register variable
+ sl/v7 r10 stack limit / stack chunk handle / reg. variable
+ fp r11 frame pointer
+ ip r12 scratch register / new-sb in inter-link-unit calls
+ sp r13 lower end of current stack frame
+ lr r14 link address / scratch register
+ pc r15 program counter
*/
.text
- .align 2
- .global __environ
.global _start
- .global exit
- .global main
+ .global __uClibc_main
.type _start,%function
- .type exit,%function
- .type main,%function
-
+ .type __uClibc_main,%function
@ r0 = argc
sub sl,sl,r3
mov BASEREG,sl
- ldr r3, .L3
- str r2,[BASEREG,r3]
-
/* pull argc, argv and envp off the stack */
ldr r0,[sp, #0]
ldr r1,[sp, #4]
ldr r2,[sp, #8]
- bl main
-/* ldr r0,=0 */
- bl exit
-
-.align 2
-.L3:
- .word __environ
-
-
-.data
- .align 2
- .global __environ
-
-__environ:
- .long 0
-
-.weak environ
-environ = __environ
-
+ /* Ok, now run uClibc's main() -- shouldn't return */
+ bl __uClibc_main