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newlib-cygwin/libgloss/msp430/crt_move_highdata.S
Mike Frysinger f5c40e04e5 libgloss: msp430: split up crt0.S source
The build system compiles crt0.S many times to produce independent
object files by defining different -DLxxx symbols for each.  This
complicates the build, and has led to some bugs in the source and
build (see the previous cleanup commits in here).  The crt_bss.S
file has also been duplicated with crt0.S leading to confusion as
to which one is the "real" one.  The only reason to keep them in
one file is to make management of the section numbers when calling
START_CRT_FUNC a little easier, but that seems trivial to check
with a quick grep across all the files.

Considering how complicated the build is now, and the bugs we've
had as a result, split the crt0.S file up into multiple source
files so we don't have to compile it multiple times.  This will
also simplify merging it into the top-level Makefile.
2024-01-19 20:21:05 -05:00

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:
Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
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,
exemplary, or consequential damages (including, but not limited to,
procurement of substitute goods or services; loss of use, data, or
profits; or business interruption) however caused and on any theory of
liability, whether in contract, strict liability, or tort (including
negligence or otherwise) arising in any way out of the use of this
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__ */