#pypp 0
#ifndef _KERNEL_HH
#define _KERNEL_HH

#include "boot-programs/sos.h"

#ifndef EXTERN
#define EXTERN extern
#endif

#define NULL 0

struct Object_base
struct Page
struct Thread
struct Message
struct Receiver
struct Capability
struct Memory

#include "arch.hh"

struct Object_base:
	// Next and previous object of any type in the same page.
	Object_base *prev_obj, *next_obj
	void free_obj (Memory *parent)
	inline bool is_free ()

template <typename _T> //
struct Object : public Object_base:
	// Next and previous object of the same type in any page.
	_T *prev, *next

struct Free : public Object <Free>:
	// This marker is ~0.  No other kernel structure may allow this value
	// at this point.  It is used to recognize free chunks.
	unsigned marker

bool Object_base::is_free ():
	return ((Free *)this)->marker == ~0

struct Page : public Object <Page>:
	unsigned physical

struct Thread : public Object <Thread>:
	Memory *address_space
	unsigned pc, sp
	Thread_arch arch
	Thread *schedule_prev, *schedule_next
	Receiver *receivers

struct Message : public Object <Message>:
	Capability *capabilities[4]
	unsigned data[4]
	unsigned protected_data

struct Receiver : public Object <Receiver>:
	Thread *owner
	Receiver *prev_owned, *next_owned
	Capability *capabilities
	Message *messages

struct Capability : public Object <Capability>:
	Receiver *target
	Capability *children
	Capability *sibling_prev, *sibling_next
	unsigned protected_data
	void invoke (unsigned d0, unsigned d1, unsigned d2, unsigned d3, Capability *c0, Capability *c1, Capability *c2, Capability *c3)
	void invalidate ()

struct Memory : public Object <Memory>:
	Memory *parent
	Free *frees
	Page *pages
	Thread *threads
	Receiver *receivers
	Capability *capabilities
	Memory *memories
	unsigned limit, used
	Memory_arch arch

	inline bool map (Page *page, unsigned address, bool write)
	inline void unmap (Page *page, unsigned address)
	inline Page *get_mapping (unsigned address)

	// Allocation of pages.
	bool use ()
	void unuse ()
	unsigned palloc ()
	unsigned zalloc ()
	void pfree (unsigned page)
	void zfree (unsigned page)

	// Allocation routines for kernel structures
	void *search_free (unsigned size, void **first)
	Page *alloc_page ()
	Thread *alloc_thread ()
	Message *alloc_message (Capability *source)
	Receiver *alloc_receiver ()
	Capability *alloc_capability (Receiver *target, Capability **parent, unsigned protected_data)
	Memory *alloc_memory ()

	void free_page (Page *page)
	void free_thread (Thread *thread)
	void free_message (Message *message)
	void free_receiver (Receiver *receiver)
	void free_capability (Capability *capability)
	void free_memory (Memory *mem)

	Capability *find_capability (unsigned code)

// Functions which can be called from assembly must not be mangled.
extern "C":
	// Panic.  n is sent over caps led.  message is currently ignored.
	void panic (unsigned n, char const *message = "")
	// Debug: switch caps led
	void led (bool one, bool two, bool three)
	void dbg_sleep (unsigned ms)

void schedule ()

struct FreePage:
	FreePage *next

EXTERN FreePage *zero_pages, *junk_pages
EXTERN Memory top_memory
EXTERN Thread *sleepers, *runners
EXTERN Thread idle
EXTERN Memory idle_memory
EXTERN Page idle_page
EXTERN Thread *first_scheduled
EXTERN Thread *current

// Defined in arch.cc
void Thread_arch_init (Thread *thread)
void Memory_arch_init (Memory *mem)
void Memory_arch_free (Memory *mem)
bool Memory_arch_map (Memory *mem, Page *page, unsigned address, bool write)
void Memory_arch_unmap (Memory *mem, Page *page, unsigned address)
Page *Memory_arch_get_mapping (Memory *mem, unsigned address)
void arch_invoke ()
void arch_schedule (Thread *previous, Thread *target)

bool Memory::map (Page *page, unsigned address, bool write):
	return Memory_arch_map (this, page, address, write)
void Memory::unmap (Page *page, unsigned address):
	Memory_arch_unmap (this, page, address)
Page *Memory::get_mapping (unsigned address):
	return Memory_arch_get_mapping (this, address)

#endif