newlib-cygwin/libgloss/msp430/crt_move_highdata.S

72 lines
2.8 KiB
ArmAsm

/* Copyright (c) 2012-2015 Red Hat Incorporated.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
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notice, this list of conditions and the following disclaimer in the
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The name of Red Hat Incorporated may not be used to endorse
or promote products derived from this software without specific
prior written permission.
This software is provided by the copyright holders and contributors
"AS IS" and any express or implied warranties, including, but not
limited to, the implied warranties of merchantability and fitness for
a particular purpose are disclaimed. In no event shall Red Hat
incorporated be liable for any direct, indirect, incidental, special,
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profits; or business interruption) however caused and on any theory of
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software, even if advised of the possibility of such damage. */
#ifdef __MSP430X_LARGE__
#include "memmodel.h"
;; 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 /* __MSP430X_LARGE__ */