diff options
Diffstat (limited to 'libc/arch-arm/bionic/crtbegin_dynamic.S')
| -rw-r--r-- | libc/arch-arm/bionic/crtbegin_dynamic.S | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/libc/arch-arm/bionic/crtbegin_dynamic.S b/libc/arch-arm/bionic/crtbegin_dynamic.S index e265923..624d611 100644 --- a/libc/arch-arm/bionic/crtbegin_dynamic.S +++ b/libc/arch-arm/bionic/crtbegin_dynamic.S @@ -30,25 +30,35 @@ .type _start,#function .globl _start -# this is the small startup code that is first run when -# any executable that is statically-linked with Bionic -# runs. +# This is the small startup code that is called from +# the dynamic linker to execute an executable once all +# dependent shared libraries have been loaded and +# initialized. # -# it's purpose is to call __libc_init with appropriate +# It's purpose is to call __libc_init as defined in +# bionic/libc_init_dynamic.c with appropriate # arguments, which are: # # - the address of the raw data block setup by the Linux # kernel ELF loader # -# - address of an "onexit" function, not used on any -# platform supported by Bionic +# - address of an "onexit" function (not used on any +# platform supported by Bionic) # # - address of the "main" function of the program. We # can't hard-code it in the adr pseudo instruction # so we use a tiny trampoline that will get relocated # by the dynamic linker before this code runs # -# - address of the constructor list +# - address of the constructors table, i.e. a table +# that points to various initialization and +# finalization sections for the program. +# +# NOTE: This code is currently placed in shared libraries +# by the build system, but will be ignored. +# +# On the other hand, the arrays defined below are +# required and will be parsed by the dynamic linker. # _start: mov r0, sp @@ -63,7 +73,7 @@ _start: .long __INIT_ARRAY__ .long __FINI_ARRAY__ .long __CTOR_LIST__ - + # the .ctors section contains a list of pointers to "constructor" # functions that need to be called in order during C library initialization, # just before the program is being run. This is a C++ requirement |