Scheduler implementation

Description

Kernel scheduler internals.

Macros
#define	STATIC   static

Functions
uint32_t *	os_thread_populate_stack (int stack_id, unsigned stack_size, entrypoint_t *entrypoint, void *data)
	Populate stack of new thread so it can be executed.
int	os_process_create (Process_t process_id, const struct OS_process_definition_t *definition)
	Create process using process definition.
void	os_boot_thread (Thread_t boot_thread)
	Start executing thread.

Macro Definition Documentation

STATIC

#define STATIC   static

Function Documentation

os_boot_thread()

void os_boot_thread

(

Thread_t

boot_thread

)

Start executing thread.

Used to actually start executing in thread mode just after the kernel has been initialized and is ready to start the first thread. This function has to perform CPU switch from privileged mode in which kernel runs into unprivileged mode in which threads are supposed to run. Thread passed to this function is in state ready to be executed by normal kernel thread switching mechanism on this platform.

Parameters

boot_thread

ID of thread that shall be started

os_process_create()

int os_process_create	(	Process_t	process_id,
		const struct OS_process_definition_t *	definition
	)

Create process using process definition.

Takes process definition and initializes MPU regions for process out of it.

Parameters

process_id	ID of process to be initialized
definition	process definition. This is constructed at compile time using OS_APPLICATION macros

Returns

E_OK if process was contructed properly, E_INVALID if process ID is already used or if process definition contains invalid section boundaries. E_OUT_OF_RANGE is returned if process ID requested is out of limits given by the size of process table.

os_thread_populate_stack()

uint32_t * os_thread_populate_stack	(	int	stack_id,
		unsigned	stack_size,
		entrypoint_t *	entrypoint,
		void *	data
	)

Populate stack of new thread so it can be executed.

Populates stack of new thread so that it can be executed with no other actions required. Returns the address where SP shall point to.

Parameters

stack_id	ID of stack to be populated
stack_size	size of stack in 32-bit quantities
entrypoint	address of thread entrypoint function
data	address of data passed to the thread as its 1st argument

Returns

Address to which the SP shall be set.