zephyr/kernel/common/bsp/init.c
Allan Stephens 2801be129a Eliminate _nano_start()
The helper function _nano_start() is no longer required (due to the
recent relocation of boot banner and kernel build timestamp code),
so the kernel's initialization code calls _nano_fiber_swap() directly.

Change-Id: I06b9f473715afbfbdd4105b0def3445f1b2e3583
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
2016-02-05 20:13:40 -05:00

182 lines
5.8 KiB
C

/* init.c - initialization module */
/*
* Copyright (c) 2011-2014 Wind River Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) 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.
*
* 3) Neither the name of Wind River Systems nor the names of its contributors
* may 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*/
/*
DESCRIPTION
This module provides the C initialization routine _Cstart() which is called
when the system is ready to run C code.
This module is responsible for initializing any basic hardware (via the
invocation of _InitHardware(), and then initializing the nanokernel. After
initializing the nanokernel the _Swap() routine is invoked to effect
a context swap to the background context (whose entry point is main()).
*/
#include <offsets.h>
#include <cputype.h>
#include <nanokernel.h>
#include <nanokernel/cpu.h>
#include <misc/printk.h>
#include <drivers/rand32.h>
#include <toolchain.h>
/* hardware initialization routine provided in BSP's system.c module */
extern void _InitHardware(void);
extern int main(void);
/* variables utilized by the microkernel */
extern char *__argv[], *__env[];
/* C++ constructor initialization implemented in common/ctors.c */
extern void _Ctors(void);
/* kernel build timestamp items */
#define BUILD_TIMESTAMP "BUILD: " __DATE__ " " __TIME__
#ifdef CONFIG_BUILD_TIMESTAMP
const char * const build_timestamp = BUILD_TIMESTAMP;
#endif
/* boot banner items */
#define BOOT_BANNER "****** BOOTING VXMICRO ******"
#if !defined(CONFIG_BOOT_BANNER)
#define PRINT_BOOT_BANNER() do { } while (0)
#elif !defined(CONFIG_BUILD_TIMESTAMP)
#define PRINT_BOOT_BANNER() printk(BOOT_BANNER "\n")
#else
#define PRINT_BOOT_BANNER() printk(BOOT_BANNER " %s\n", build_timestamp)
#endif
#ifdef CONFIG_STACK_CANARIES
/*******************************************************************************
*
* STACK_CANARY_INIT - initialize the kernel's stack canary
*
* This macro, only called from the BSP's _Cstart() routine, is used to
* initialize the kernel's stack canary. Both of the supported Intel and GNU
* compilers currently support the stack canary global variable
* <__stack_chk_guard>. However, as this might not hold true for all future
* releases, the initialization of the kernel stack canary has been abstracted
* out for maintenance and backwards compatibility reasons.
*
* INTERNAL
* Modifying __stack_chk_guard directly at runtime generates a build error
* with ICC 13.0.2 20121114 on Windows 7. In-line assembly is used as a
* workaround.
*/
extern void *__stack_chk_guard;
#if defined(VXMICRO_ARCH_x86)
#define _MOVE_INSTR "movl "
#elif defined(VXMICRO_ARCH_arm)
#define _MOVE_INSTR "str "
#else
#error "Unknown VXMICRO_ARCH type"
#endif /* VXMICRO_ARCH */
#define STACK_CANARY_INIT() \
do { \
register void *tmp; \
_Rand32Init(); \
tmp = (void *)_Rand32Get(); \
__asm__ volatile(_MOVE_INSTR "%1, %0;\n\t" \
: "=m"(__stack_chk_guard) \
: "r"(tmp)); \
} while (0)
#else /* !CONFIG_STACK_CANARIES */
#define STACK_CANARY_INIT()
#endif /* CONFIG_STACK_CANARIES */
/*******************************************************************************
*
* _Cstart - C portion of board initialization
*
* This routine is called from the crt0.s routine __start(). It's the first
* C code executed by the image and it's assumed that:
* a) the processor has already been switched into 32-bit protect mode, and
* b) the BSS are has already been cleared/zeroed.
*
* RETURNS: Does not return
*/
FUNC_NORETURN void _Cstart(void)
{
/* floating point operations are NOT performed during nanokernel init */
char dummyCCS[__tCCS_NOFLOAT_SIZEOF];
/*
* Initialize the nanokernel. This step includes initializing the
* interrupt subsystem, which must be performed before the
* hardware initialization phase (by _InitHardware).
*
* For the time being don't pass any arguments to the nanokernel.
* (Once the future direction of the main() prototype is sorted out
* both __argv and _env may come into play.)
*/
_nano_init((tCCS *)&dummyCCS, 0, (char **)0, (char **)0);
/* perform basic hardware initialization */
_InitHardware();
STACK_CANARY_INIT();
/* invoke C++ constructors */
_Ctors();
/* display boot banner */
PRINT_BOOT_BANNER();
/* context switch into background context (entry function is main()) */
_nano_fiber_swap();
/*
* Compiler can't tell that the above routines won't return and issues
* a warning unless we explicitly tell it that control never gets this
* far.
*/
CODE_UNREACHABLE;
}