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/*
ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* @file GCC/crt0.s
* @brief Generic PowerPC startup file for GCC.
*
* @addtogroup PPC_GCC_CORE
* @{
*/
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
#if !defined(FALSE) || defined(__DOXYGEN__)
#define FALSE 0
#endif
#if !defined(TRUE) || defined(__DOXYGEN__)
#define TRUE 1
#endif
/*===========================================================================*/
/* Module pre-compile time settings. */
/*===========================================================================*/
/**
* @brief Stack segments initialization switch.
*/
#if !defined(CRT0_STACKS_FILL_PATTERN) || defined(__DOXYGEN__)
#define CRT0_STACKS_FILL_PATTERN 0x55555555
#endif
/**
* @brief Stack segments initialization switch.
*/
#if !defined(CRT0_INIT_STACKS) || defined(__DOXYGEN__)
#define CRT0_INIT_STACKS TRUE
#endif
/**
* @brief DATA segment initialization switch.
*/
#if !defined(CRT0_INIT_DATA) || defined(__DOXYGEN__)
#define CRT0_INIT_DATA TRUE
#endif
/**
* @brief BSS segment initialization switch.
*/
#if !defined(CRT0_INIT_BSS) || defined(__DOXYGEN__)
#define CRT0_INIT_BSS TRUE
#endif
/**
* @brief Constructors invocation switch.
*/
#if !defined(CRT0_CALL_CONSTRUCTORS) || defined(__DOXYGEN__)
#define CRT0_CALL_CONSTRUCTORS TRUE
#endif
/**
* @brief Destructors invocation switch.
*/
#if !defined(CRT0_CALL_DESTRUCTORS) || defined(__DOXYGEN__)
#define CRT0_CALL_DESTRUCTORS TRUE
#endif
/*===========================================================================*/
/* Code section. */
/*===========================================================================*/
#if !defined(__DOXYGEN__)
.section .crt0, "ax"
.align 2
.globl _boot_address
.type _boot_address, @function
_boot_address:
/* Stack setup.*/
lis %r1, __process_stack_end__@h
ori %r1, %r1, __process_stack_end__@l
li %r0, 0
stwu %r0, -8(%r1)
/* Small sections registers initialization.*/
lis %r2, __sdata2_start__@h
ori %r2, %r2, __sdata2_start__@l
lis %r13, __sdata_start__@h
ori %r13, %r13, __sdata_start__@l
/* Early initialization.*/
bl __early_init
#if CRT0_INIT_STACKS == TRUE
/* Stacks fill pattern.*/
lis %r7, CRT0_STACKS_FILL_PATTERN@h
ori %r7, %r7, CRT0_STACKS_FILL_PATTERN@l
/* IRQ Stack initialization. Note, the architecture does not use this
stack, the size is usually zero. An OS can have special SW handling
and require this. A 4 bytes alignment is assmend and required.*/
lis %r4, __irq_stack_base__@h
ori %r4, %r4, __irq_stack_base__@l
lis %r5, __irq_stack_end__@h
ori %r5, %r5, __irq_stack_end__@l
.irqsloop:
cmpl cr0, %r4, %r5
bge cr0, .irqsend
stw %r7, 0(%r4)
addi %r4, %r4, 4
b .irqsloop
.irqsend:
/* Process Stack initialization. Note, does not overwrite the already
written EABI frame. A 4 bytes alignment is assmend and required.*/
lis %r4, __process_stack_base__@h
ori %r4, %r4, __process_stack_base__@l
lis %r5, (__process_stack_end__ - 8)@h
ori %r5, %r5, (__process_stack_end__ - 8)@l
.prcsloop:
cmpl cr0, %r4, %r5
bge cr0, .prcsend
stw %r7, 0(%r4)
addi %r4, %r4, 4
b .prcsloop
.prcsend:
#endif
#if CRT0_INIT_BSS == TRUE
/* BSS clearing.*/
lis %r4, __bss_start__@h
ori %r4, %r4, __bss_start__@l
lis %r5, __bss_end__@h
ori %r5, %r5, __bss_end__@l
li %r7, 0
.bssloop:
cmpl cr0, %r4, %r5
bge cr0, .bssend
stw %r7, 0(%r4)
addi %r4, %r4, 4
b .bssloop
.bssend:
#endif
#if CRT0_INIT_DATA == TRUE
/* DATA initialization.*/
lis %r4, __romdata_start__@h
ori %r4, %r4, __romdata_start__@l
lis %r5, __data_start__@h
ori %r5, %r5, __data_start__@l
lis %r6, __data_end__@h
ori %r6, %r6, __data_end__@l
.dataloop:
cmpl cr0, %r5, %r6
bge cr0, .dataend
lwz %r7, 0(%r4)
addi %r4, %r4, 4
stw %r7, 0(%r5)
addi %r5, %r5, 4
b .dataloop
.dataend:
#endif
/* Late initialization.*/
bl __late_init
#if CRT0_CALL_CONSTRUCTORS == TRUE
/* Constructors invocation.*/
lis %r4, __init_array_start@h
ori %r4, %r4, __init_array_start@l
lis %r5, __init_array_end@h
ori %r5, %r5, __init_array_end@l
.iniloop:
cmplw %cr0, %r4, %r5
bge %cr0, .iniend
lwz %r6, 0(%r4)
mtctr %r6
addi %r4, %r4, 4
bctrl
b .iniloop
.iniend:
#endif
/* Main program invocation.*/
bl main
#if CRT0_CALL_DESTRUCTORS == TRUE
/* Destructors invocation.*/
lis %r4, __fini_array_start@h
ori %r4, %r4, __fini_array_start@l
lis %r5, __fini_array_end@h
ori %r5, %r5, __fini_array_end@l
.finiloop:
cmplw %cr0, %r4, %r5
bge %cr0, .finiend
lwz %r6, 0(%r4)
mtctr %r6
addi %r4, %r4, 4
bctrl
b .finiloop
.finiend:
#endif
/* Branching to the defined exit handler.*/
b __default_exit
/* Default main exit code, infinite loop.*/
.weak __default_exit
.type __default_exit, @function
__default_exit:
b __default_exit
/* Default early initialization code, none.*/
.weak __early_init
.type __early_init, @function
__early_init:
blr
/* Default late initialization code, none.*/
.weak __late_init
.type __late_init, @function
__late_init:
blr
#endif /* !defined(__DOXYGEN__) */
/** @} */
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