diff options
| -rw-r--r-- | ldso/ldso/arm/dl-startup.h | 69 | ||||
| -rw-r--r-- | ldso/ldso/arm/dl-sysdep.h | 18 | ||||
| -rw-r--r-- | libc/sysdeps/linux/arm/clone.S | 6 | ||||
| -rw-r--r-- | libc/sysdeps/linux/arm/vfork.S | 8 |
4 files changed, 100 insertions, 1 deletions
diff --git a/ldso/ldso/arm/dl-startup.h b/ldso/ldso/arm/dl-startup.h index 8ebc0b288..fa7c9651e 100644 --- a/ldso/ldso/arm/dl-startup.h +++ b/ldso/ldso/arm/dl-startup.h @@ -4,6 +4,7 @@ * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org> */ +#if defined(__arm__) asm( " .text\n" " .globl _start\n" @@ -40,7 +41,11 @@ asm( " ldr r0, .L_FINI_PROC\n" " ldr r0, [sl, r0]\n" " @ jump to the user_s entry point\n" +#if defined(__THUMB_INTERWORK__) + " bx r6\n" +#else " mov pc, r6\n" +#endif ".L_GET_GOT:\n" " .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n" ".L_SKIP_ARGS:\n" @@ -51,6 +56,70 @@ asm( " .size _start,.-_start\n" ".previous\n" ); +#else +asm( + " .text\n" + " .arm\n" + " .globl _start\n" + " .type _start,%function\n" + "_start:\n" + " @ dumb: can't persuade the linker to make the start address\n" + " @ odd, so use an arm function and change to thumb (_dl_start\n" + " @ is thumb)\n" + " adr r0, __dl_thumb_start+1\n" + " bx r0\n" + "\n\n" + " .thumb\n" + " .globl __dl_thumb_start\n" + " .thumb_func\n" + " .type __dl_thumb_start,%function\n" + "__dl_thumb_start:\n" + " @ at start time, all the args are on the stack\n" + " mov r0, sp\n" + " bl _dl_start\n" + " @ returns user entry point in r0\n" + " mov r6, r0\n" + " @ we are PIC code, so get global offset table\n" + " ldr r7, .L_GET_GOT\n" + ".L_GOT_GOT:\n" + " add r7, pc\n" + " @ See if we were run as a command with the executable file\n" + " @ name as an extra leading argument.\n" + " ldr r4, .L_SKIP_ARGS\n" + " ldr r4, [r7, r4]\n" + " @ get the original arg count\n" + " ldr r1, [sp]\n" + " @ subtract _dl_skip_args from it\n" + " sub r1, r1, r4\n" + " @ adjust the stack pointer to skip them\n" + " lsl r4, r4, #2\n" + " add sp, r4\n" + " @ get the argv address\n" + " add r2, sp, #4\n" + " @ store the new argc in the new stack location\n" + " str r1, [sp]\n" + " @ compute envp\n" + " lsl r3, r1, #2\n" + " add r3, r3, r2\n" + " add r3, #4\n" + "\n\n" + " @ load the finalizer function\n" + " ldr r0, .L_FINI_PROC\n" + " ldr r0, [r7, r0]\n" + " @ jump to the user_s entry point\n" + " bx r6\n" + "\n\n" + ".L_GET_GOT:\n" + " .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n" + ".L_SKIP_ARGS:\n" + " .word _dl_skip_args(GOTOFF)\n" + ".L_FINI_PROC:\n" + " .word _dl_fini(GOT)\n" + "\n\n" + " .size _start,.-_start\n" + ".previous\n" +); +#endif /* Get a pointer to the argv array. On many platforms this can be just diff --git a/ldso/ldso/arm/dl-sysdep.h b/ldso/ldso/arm/dl-sysdep.h index 794c86a0c..194fd2eb7 100644 --- a/ldso/ldso/arm/dl-sysdep.h +++ b/ldso/ldso/arm/dl-sysdep.h @@ -85,7 +85,25 @@ elf_machine_load_address (void) extern void __dl_start asm ("_dl_start"); Elf32_Addr got_addr = (Elf32_Addr) &__dl_start; Elf32_Addr pcrel_addr; +#if !defined __thumb__ asm ("adr %0, _dl_start" : "=r" (pcrel_addr)); +#else + int tmp; + /* The above adr will not work on thumb because it + * is negative. The only safe way is to temporarily + * swap to arm. + */ + asm( ".align 2\n" + " bx pc\n" + " nop \n" + " .arm \n" + " adr %0, _dl_start\n" + " .align 2\n" + " orr %1, pc, #1\n" + " bx %1\n" + " .force_thumb\n" + : "=r" (pcrel_addr), "=&r" (tmp)); +#endif return pcrel_addr - got_addr; } diff --git a/libc/sysdeps/linux/arm/clone.S b/libc/sysdeps/linux/arm/clone.S index 6672c7d6e..98b1296c0 100644 --- a/libc/sysdeps/linux/arm/clone.S +++ b/libc/sysdeps/linux/arm/clone.S @@ -52,7 +52,11 @@ clone: DO_CALL (clone) movs a1, a1 blt __error - movne pc, lr +#if defined(__THUMB_INTERWORK__) + bxne lr +#else + movne pc, lr +#endif @ pick the function arg and call address off the stack and execute ldr r0, [sp, #4] diff --git a/libc/sysdeps/linux/arm/vfork.S b/libc/sysdeps/linux/arm/vfork.S index e13636940..486a7e8e4 100644 --- a/libc/sysdeps/linux/arm/vfork.S +++ b/libc/sysdeps/linux/arm/vfork.S @@ -26,7 +26,11 @@ __vfork: #ifdef __NR_vfork DO_CALL (vfork) cmn r0, #4096 +#if defined(__THUMB_INTERWORK__) + bxcc lr +#else movcc pc, lr +#endif /* Check if vfork even exists. */ ldr r1, =-ENOSYS @@ -39,7 +43,11 @@ __vfork: cmn r0, #4096 /* Syscall worked. Return to child/parent */ +#if defined(__THUMB_INTERWORK__) + bxcc lr +#else movcc pc, lr +#endif __error: b __syscall_error |