diff options
Diffstat (limited to 'libgloss/msp430/crt0.S')
| -rw-r--r-- | libgloss/msp430/crt0.S | 192 |
1 files changed, 1 insertions, 191 deletions
diff --git a/libgloss/msp430/crt0.S b/libgloss/msp430/crt0.S index c0b258f50..affc2c9a8 100644 --- a/libgloss/msp430/crt0.S +++ b/libgloss/msp430/crt0.S @@ -13,13 +13,6 @@ #include "memmodel.h" -;; The linker links all .crt_* sections in asciibetical order at the -;; same place. So, the four digits in .crt_NNNN_xxx name created by -;; the START_CRT_FUNC macro determine the link order, so, keep them -;; in sequential order here. The first two digits are set here, the -;; second two allow users to insert code between code fragments here. - -#if L0 .section ".resetvec", "a" __msp430_resetvec_hook: .word __crt0_start @@ -56,9 +49,8 @@ START_CRT_FUNC 0000 start mov_ #__stack, R1 END_CRT_FUNC start -#endif -;; The CRT functions below will only be present in the final linked +;; The CRT functions will only be present in the final linked ;; executable if the assembler decides they are needed. The assembler will ;; only define the symbol necessary to prevent them being garbage collected ;; by the linker if the file being assembled has a specific section, @@ -67,185 +59,3 @@ END_CRT_FUNC start ;; if it detects that main() has an epilogue. For example, if main() has a ;; while(1) loop at the end, GCC will not generate an epilogue (since it won't ;; return) and __crt0_call_exit won't be included. - -#if Lbss -;; This function is responsible for initializing the contents of the -;; .bss section. - -START_CRT_FUNC 0100 init_bss - - mov_ #__bssstart, R12 - clr.w R13 - mov_ #__bsssize, R14 -#ifdef __MSP430X_LARGE__ - clr.w R15 ; We assume that __bsssize is never > 64K -#endif - call_ #memset - -END_CRT_FUNC init_bss -#endif /* Lbss */ - - -#ifdef __MSP430X_LARGE__ -#if Lhigh_bss -;; This function is responsible for initializing the contents of the -;; .upper.bss section. - -START_CRT_FUNC 0200 init_highbss - - mov_ #__high_bssstart, R12 - mov.w #0, R13 - mov_ #__high_bsssize, R14 - ;; If __high_bsssize is zero then skip the call to memset. - ;; This can happen if all of the bss data was placed into .either.bss. - cmp.w #0, R14 - jeq 1f - call_ #memset -1: -END_CRT_FUNC init_highbss -#endif /* Lhigh_bss */ -#endif /* __MSP430X_LARGE__ */ - - -#if Lmovedata -;; This function is responsible for copying the -;; contents of the .data section from its load address (in ROM) to -;; its run-time address (in RAM). - -START_CRT_FUNC 0300 movedata - - mov_ #__datastart, R12 - mov_ #__romdatastart, R13 - - ;; memmove and memcpy do not currently work when src == dst - cmp_ R12, R13 - jeq 1f - - mov_ #__romdatacopysize, R14 - - call_ #memmove -1: -END_CRT_FUNC movedata -#endif /* Lmovedata */ - - -#ifdef __MSP430X_LARGE__ -#if Lmove_highdata -;; This function is responsible for making sure that the -;; contents of the .upper.data section have their correct startup values. -;; If a copy of the .upper.data section is stored in ROM then this means -;; copying the contents into HIFRAM. If a copy of .upper.data is stored in a -;; shadow section in HIFRAM then this means copying from the shadow section -;; into the real section. - -START_CRT_FUNC 0400 move_highdata - ;; __rom_highdatacopysize may be zero. Test this first because - ;; its value may come from the weak definitions above and we do - ;; not want to access the memory at address 0 pointed to by the - ;; weak definition of __upper_data_init. - mov.w #__rom_highdatacopysize, R14 - cmp.w #0, R14 - jeq 3f - - /* Test our status word. */ - cmpx.w #0, &__upper_data_init - jeq 1f - /* Status word is non-zero - copy from shadow into upper. */ - mov_ #__high_datastart, R12 - mov_ #__rom_highdatastart, R13 - jmp 2f - -1: /* Status word is zero. Copy from upper to shadow and change status word. */ - movx.w #1, &__upper_data_init - mov_ #__rom_highdatastart, R12 - mov_ #__high_datastart, R13 - -2: ;; __rom_highdatacopysize may be zero. memmove should cope. - mov.w #__rom_highdatacopysize, R14 - - call_ #memmove -3: -END_CRT_FUNC move_highdata -#endif /* Lmove_highdata */ -#endif /* __MSP430X_LARGE__ */ - -#if Lrun_preinit_array -;; This function is responsible for setting up the arguments -;; required for __crt0_run_array, to run the functions in .preinit_array. -START_CRT_FUNC 0500 run_preinit_array - - mov_ #__preinit_array_start, R4 - mov_ #__preinit_array_end, R5 - mov_ #PTRsz, R6 - call_ #__crt0_run_array - -END_CRT_FUNC run_preinit_array -#endif /* Lrun_preinit_array */ - -#if Lrun_init_array -;; This function is responsible for setting up the arguments -;; required for __crt0_run_array, to run the functions in .init_array. -START_CRT_FUNC 0600 run_init_array - - mov_ #__init_array_start, R4 - mov_ #__init_array_end, R5 - mov_ #PTRsz, R6 - call_ #__crt0_run_array - -END_CRT_FUNC run_init_array -#endif /* Lrun_init_array */ - - -#if Lmain -;; This function is always included and calls main(). - -START_CRT_FUNC 0800 call_main - - clr.w R12 ; Set argc == 0 - call_ #main - -END_CRT_FUNC call_main -#endif /* Lmain */ - -#if Lcallexit -;; This function is responsible for calling exit once main has finished. - -START_CRT_FUNC 0900 call_exit - - call_ #_exit - -END_CRT_FUNC call_exit -#endif /* Lcallexit */ - -;---------------------------------------- - -#if Lrun_fini_array -;; This function is responsible for setting up the arguments -;; required for __crt0_run_array, to run the functions in .fini_array. -START_CRT_FUNC 1000 run_fini_array - - mov_ #__fini_array_start, R4 - mov_ #__fini_array_end, R5 - mov_ #-PTRsz, R6 - call_ #__crt0_run_array - -END_CRT_FUNC run_fini_array -#endif /* Lrun_fini_array */ - -#if Lrun_array -;; Note - this section is only included in the startup code of the application -;; if it is needed by one of the above run_*_array functions. -START_CRT_FUNC 1100 run_array - - cmp_ R4, R5 - jeq _msp430_run_done - mov_ @R4, R7 - add_ R6, R4 - call_ R7 - br_ #__crt0_run_array - -END_CRT_FUNC run_array - -_msp430_run_done: - ret_ -#endif /* Lrun_array */ |