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musl/crt/arm/crtn.s

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ArmAsm
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add support for ctors/dtors on arm with modern gcc a while back, gcc switched from using the old _init/_fini fragments method for calling ctors and dtors on arm to the __init_array and __fini_array method. unfortunately, on glibc this depends on ugly hacks involving making libc.so a linker script and pulling parts of libc into the main program binary. so I cheat a little bit, and just write asm to iterate over the init/fini arrays from the _init/_fini asm. the same approach could be used on any arch it's needed on, but for now arm is the only one.
2012-12-08 04:04:49 +00:00
.weak __init_array_start
.weak __init_array_end
add support for init/finit (constructors and destructors) this is mainly in hopes of supporting c++ (not yet possible for other reasons) but will also help applications/libraries which use (and more often, abuse) the gcc __attribute__((__constructor__)) feature in "C" code. x86_64 and arm versions of the new startup asm are untested and may have minor problems.
2012-02-06 19:39:09 +00:00
.section .init
add support for ctors/dtors on arm with modern gcc a while back, gcc switched from using the old _init/_fini fragments method for calling ctors and dtors on arm to the __init_array and __fini_array method. unfortunately, on glibc this depends on ugly hacks involving making libc.so a linker script and pulling parts of libc into the main program binary. so I cheat a little bit, and just write asm to iterate over the init/fini arrays from the _init/_fini asm. the same approach could be used on any arch it's needed on, but for now arm is the only one.
2012-12-08 04:04:49 +00:00
adr lr, 1f
ldr r4, 2f
ldr r5, 2f+4
add r4, r4, lr
add r5, r5, lr
1: adr lr, 1b
cmp r4, r5
beq 3f
ldmia r4!, {r3}
ldm sp, {r0,r1,r2}
tst r3,#1
moveq pc,r3
bx r3
3: pop {r0,r1,r2,r4,r5,lr}
add support for init/finit (constructors and destructors) this is mainly in hopes of supporting c++ (not yet possible for other reasons) but will also help applications/libraries which use (and more often, abuse) the gcc __attribute__((__constructor__)) feature in "C" code. x86_64 and arm versions of the new startup asm are untested and may have minor problems.
2012-02-06 19:39:09 +00:00
tst lr,#1
moveq pc,lr
bx lr
add support for ctors/dtors on arm with modern gcc a while back, gcc switched from using the old _init/_fini fragments method for calling ctors and dtors on arm to the __init_array and __fini_array method. unfortunately, on glibc this depends on ugly hacks involving making libc.so a linker script and pulling parts of libc into the main program binary. so I cheat a little bit, and just write asm to iterate over the init/fini arrays from the _init/_fini asm. the same approach could be used on any arch it's needed on, but for now arm is the only one.
2012-12-08 04:04:49 +00:00
2: .word __init_array_start-1b
.word __init_array_end-1b
add support for init/finit (constructors and destructors) this is mainly in hopes of supporting c++ (not yet possible for other reasons) but will also help applications/libraries which use (and more often, abuse) the gcc __attribute__((__constructor__)) feature in "C" code. x86_64 and arm versions of the new startup asm are untested and may have minor problems.
2012-02-06 19:39:09 +00:00
.section .fini
add support for ctors/dtors on arm with modern gcc a while back, gcc switched from using the old _init/_fini fragments method for calling ctors and dtors on arm to the __init_array and __fini_array method. unfortunately, on glibc this depends on ugly hacks involving making libc.so a linker script and pulling parts of libc into the main program binary. so I cheat a little bit, and just write asm to iterate over the init/fini arrays from the _init/_fini asm. the same approach could be used on any arch it's needed on, but for now arm is the only one.
2012-12-08 04:04:49 +00:00
pop {r4,r5,r6,lr}
add support for init/finit (constructors and destructors) this is mainly in hopes of supporting c++ (not yet possible for other reasons) but will also help applications/libraries which use (and more often, abuse) the gcc __attribute__((__constructor__)) feature in "C" code. x86_64 and arm versions of the new startup asm are untested and may have minor problems.
2012-02-06 19:39:09 +00:00
tst lr,#1
moveq pc,lr
bx lr