KernelInitSubsystem

Table of Contents Kernel Init/Stop subsystem Init stages Early init Main init Late init Stop stages Early Stop Prepare Stop Final Stop

Kernel Init/Stop subsystem

To make kernel init/stop process more or less clear, Init/Stop subsystem is made.

Init stages

Any subsystem can register up to three init functions.

#include <kernel/init.h>

static void early_init(void);
static void main_init(void);
static void late_init(void);

INIT_ME( early_init, main_init, late_init ); // Any one can be zero

Early init

• • After this stage you must ensure that all public interfaces of your subsystem are callable**.

You can return failure for all of them, but not crash.

Very limited subset of kernel services is working.

What is **NOT** working:

 * IRQ allocator
 * Paging
 * Timers and timed calls
 * Threads and locking. Though you **can** use spinlocks.
 * DPC (deferred procedure calls - threadlets/light threads)
 * Drivers
 * Network, of course.

Main init

• • After this stage your subsystem must be mostly working**.

You can call other subsystems and integrate with them.

What is still **NOT** working:

• Video
• Phase 2-3-4 drivers
• Unix subsystem
• USB
• Disk IO
• Phantom native subsystem (persistent memory and virtual machine)

Network **IS** working at this stage, though.

Late init

• • After this stage your subsystem must be completely working**.

You can call anything in kernel.

Stop stages

static void early_stop(void);
static void prepare_stop(void);
static void final_stop(void);

STOP_ME( early_stop, prepare_stop, final_stop );

Early Stop

VM threads stopped. SMP turned off.

Prepare Stop

Stop calling others at this stage.

Final Stop

Stop servicing calls.