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/*
* Copyright (c) 2010-2014 Wind River Systems, Inc.
*
* 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
* @brief Kernel initialization module
*
* This module contains routines that are used to initialize the kernel.
*/
#include <zephyr.h>
#include <offsets_short.h>
#include <kernel.h>
#include <misc/printk.h>
#include <drivers/rand32.h>
#include <sections.h>
#include <toolchain.h>
#include <kernel_structs.h>
#include <device.h>
#include <init.h>
#include <linker-defs.h>
#include <ksched.h>
#include <version.h>
#include <string.h>
/* 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 ZEPHYR OS v" KERNEL_VERSION_STRING
#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
/* boot time measurement items */
#ifdef CONFIG_BOOT_TIME_MEASUREMENT
uint64_t __noinit __start_tsc; /* timestamp when kernel starts */
uint64_t __noinit __main_tsc; /* timestamp when main task starts */
uint64_t __noinit __idle_tsc; /* timestamp when CPU goes idle */
#endif
/* init/main and idle threads */
#define IDLE_STACK_SIZE CONFIG_IDLE_STACK_SIZE
#if CONFIG_MAIN_STACK_SIZE & (STACK_ALIGN - 1)
#error "MAIN_STACK_SIZE must be a multiple of the stack alignment"
#endif
#if IDLE_STACK_SIZE & (STACK_ALIGN - 1)
#error "IDLE_STACK_SIZE must be a multiple of the stack alignment"
#endif
/* Some projects may specify their main thread and parameters in the
* MDEF file. In this case, we need to use the stack size specified there
* and not in Kconfig
*/
#if defined(MDEF_MAIN_STACK_SIZE) && \
(MDEF_MAIN_STACK_SIZE > CONFIG_MAIN_STACK_SIZE)
#define MAIN_STACK_SIZE MDEF_MAIN_STACK_SIZE
#else
#define MAIN_STACK_SIZE CONFIG_MAIN_STACK_SIZE
#endif
char __noinit __stack _main_stack[MAIN_STACK_SIZE];
char __noinit __stack _idle_stack[IDLE_STACK_SIZE];
k_tid_t const _main_thread = (k_tid_t)_main_stack;
k_tid_t const _idle_thread = (k_tid_t)_idle_stack;
/*
* storage space for the interrupt stack
*
* Note: This area is used as the system stack during kernel initialization,
* since the kernel hasn't yet set up its own stack areas. The dual purposing
* of this area is safe since interrupts are disabled until the kernel context
* switches to the init thread.
*/
#if CONFIG_ISR_STACK_SIZE & (STACK_ALIGN - 1)
#error "ISR_STACK_SIZE must be a multiple of the stack alignment"
#endif
char __noinit __stack _interrupt_stack[CONFIG_ISR_STACK_SIZE];
#ifdef CONFIG_SYS_CLOCK_EXISTS
#include <misc/dlist.h>
#define initialize_timeouts() do { \
sys_dlist_init(&_timeout_q); \
} while ((0))
#else
#define initialize_timeouts() do { } while ((0))
#endif
extern void idle(void *unused1, void *unused2, void *unused3);
/**
*
* @brief Clear BSS
*
* This routine clears the BSS region, so all bytes are 0.
*
* @return N/A
*/
void _bss_zero(void)
{
memset(&__bss_start, 0,
((uint32_t) &__bss_end - (uint32_t) &__bss_start));
}
#ifdef CONFIG_XIP
/**
*
* @brief Copy the data section from ROM to RAM
*
* This routine copies the data section from ROM to RAM.
*
* @return N/A
*/
void _data_copy(void)
{
memcpy(&__data_ram_start, &__data_rom_start,
((uint32_t) &__data_ram_end - (uint32_t) &__data_ram_start));
}
#endif
/**
*
* @brief Mainline for kernel's background task
*
* This routine completes kernel initialization by invoking the remaining
* init functions, then invokes application's main() routine.
*
* @return N/A
*/
static void _main(void *unused1, void *unused2, void *unused3)
{
ARG_UNUSED(unused1);
ARG_UNUSED(unused2);
ARG_UNUSED(unused3);
_sys_device_do_config_level(_SYS_INIT_LEVEL_POST_KERNEL);
/* These 3 are deprecated */
_sys_device_do_config_level(_SYS_INIT_LEVEL_SECONDARY);
_sys_device_do_config_level(_SYS_INIT_LEVEL_NANOKERNEL);
_sys_device_do_config_level(_SYS_INIT_LEVEL_MICROKERNEL);
/* Final init level before app starts */
_sys_device_do_config_level(_SYS_INIT_LEVEL_APPLICATION);
#ifdef CONFIG_CPLUSPLUS
/* Process the .ctors and .init_array sections */
extern void __do_global_ctors_aux(void);
extern void __do_init_array_aux(void);
__do_global_ctors_aux();
__do_init_array_aux();
#endif
_init_static_threads();
#ifdef CONFIG_BOOT_TIME_MEASUREMENT
/* record timestamp for kernel's _main() function */
extern uint64_t __main_tsc;
__main_tsc = _tsc_read();
#endif
extern void main(void);
/* If we're going to load the MDEF main() in this context, we need
* to now set the priority to be what was specified in the MDEF file
*/
#if defined(MDEF_MAIN_THREAD_PRIORITY) && \
(MDEF_MAIN_THREAD_PRIORITY != CONFIG_MAIN_THREAD_PRIORITY)
k_thread_priority_set(_main_thread, MDEF_MAIN_THREAD_PRIORITY);
#endif
main();
/* Terminate thread normally since it has no more work to do */
_main_thread->base.thread_state &= ~K_ESSENTIAL;
}
void __weak main(void)
{
/* NOP default main() if the application does not provide one. */
}
/**
*
* @brief Initializes kernel data structures
*
* This routine initializes various kernel data structures, including
* the init and idle threads and any architecture-specific initialization.
*
* Note that all fields of "_kernel" are set to zero on entry, which may
* be all the initialization many of them require.
*
* @return N/A
*/
static void prepare_multithreading(struct k_thread *dummy_thread)
{
#ifdef CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN
ARG_UNUSED(dummy_thread);
#else
/*
* Initialize the current execution thread to permit a level of
* debugging output if an exception should happen during kernel
* initialization. However, don't waste effort initializing the
* fields of the dummy thread beyond those needed to identify it as a
* dummy thread.
*/
_current = dummy_thread;
dummy_thread->base.thread_state = K_ESSENTIAL;
#endif
/* _kernel.ready_q is all zeroes */
/*
* The interrupt library needs to be initialized early since a series
* of handlers are installed into the interrupt table to catch
* spurious interrupts. This must be performed before other kernel
* subsystems install bonafide handlers, or before hardware device
* drivers are initialized.
*/
_IntLibInit();
/* ready the init/main and idle threads */
for (int ii = 0; ii < K_NUM_PRIORITIES; ii++) {
sys_dlist_init(&_ready_q.q[ii]);
}
/*
* prime the cache with the main thread since:
*
* - the cache can never be NULL
* - the main thread will be the one to run first
* - no other thread is initialized yet and thus their priority fields
* contain garbage, which would prevent the cache loading algorithm
* to work as intended
*/
_ready_q.cache = _main_thread;
_new_thread(_main_stack, MAIN_STACK_SIZE,
_main, NULL, NULL, NULL,
CONFIG_MAIN_THREAD_PRIORITY, K_ESSENTIAL);
_mark_thread_as_started(_main_thread);
_add_thread_to_ready_q(_main_thread);
#ifdef CONFIG_MULTITHREADING
_new_thread(_idle_stack, IDLE_STACK_SIZE,
idle, NULL, NULL, NULL,
K_LOWEST_THREAD_PRIO, K_ESSENTIAL);
_mark_thread_as_started(_idle_thread);
_add_thread_to_ready_q(_idle_thread);
#endif
initialize_timeouts();
/* perform any architecture-specific initialization */
nanoArchInit();
}
static void switch_to_main_thread(void)
{
#ifdef CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN
_arch_switch_to_main_thread(_main_stack, MAIN_STACK_SIZE, _main);
#else
/*
* Context switch to main task (entry function is _main()): the
* current fake thread is not on a wait queue or ready queue, so it
* will never be rescheduled in.
*/
_Swap(irq_lock());
#endif
}
#ifdef CONFIG_STACK_CANARIES
/**
*
* @brief Initialize the kernel's stack canary
*
* This macro initializes the kernel's stack canary global variable,
* __stack_chk_guard, with a random value.
*
* INTERNAL
* Depending upon the compiler, modifying __stack_chk_guard directly at runtime
* may generate a build error. In-line assembly is used as a workaround.
*/
extern void *__stack_chk_guard;
#if defined(CONFIG_X86)
#define _MOVE_INSTR "movl "
#elif defined(CONFIG_ARM)
#define _MOVE_INSTR "str "
#elif defined(CONFIG_ARC)
#define _MOVE_INSTR "st "
#else
#error "Unknown Architecture type"
#endif /* CONFIG_X86 */
#define STACK_CANARY_INIT() \
do { \
register void *tmp; \
tmp = (void *)sys_rand32_get(); \
__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 */
/**
*
* @brief Initialize kernel
*
* This routine is invoked when the system is ready to run C code. The
* processor must be running in 32-bit mode, and the BSS must have been
* cleared/zeroed.
*
* @return Does not return
*/
FUNC_NORETURN void _Cstart(void)
{
#ifdef CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN
void *dummy_thread = NULL;
#else
/* floating point is NOT used during kernel init */
char __stack dummy_stack[_K_THREAD_NO_FLOAT_SIZEOF];
void *dummy_thread = dummy_stack;
#endif
/*
* Initialize kernel data structures. This step includes
* initializing the interrupt subsystem, which must be performed
* before the hardware initialization phase.
*/
prepare_multithreading(dummy_thread);
/* Deprecated */
_sys_device_do_config_level(_SYS_INIT_LEVEL_PRIMARY);
/* perform basic hardware initialization */
_sys_device_do_config_level(_SYS_INIT_LEVEL_PRE_KERNEL_1);
_sys_device_do_config_level(_SYS_INIT_LEVEL_PRE_KERNEL_2);
/* initialize stack canaries */
STACK_CANARY_INIT();
/* display boot banner */
PRINT_BOOT_BANNER();
switch_to_main_thread();
/*
* 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;
}