diff options
Diffstat (limited to 'libc/sysdeps/linux/arm/crt0.S')
| -rw-r--r-- | libc/sysdeps/linux/arm/crt0.S | 86 |
1 files changed, 32 insertions, 54 deletions
diff --git a/libc/sysdeps/linux/arm/crt0.S b/libc/sysdeps/linux/arm/crt0.S index 3660f4167..a0fad121c 100644 --- a/libc/sysdeps/linux/arm/crt0.S +++ b/libc/sysdeps/linux/arm/crt0.S @@ -12,39 +12,35 @@ 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: @@ -52,35 +48,17 @@ _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 |