24 files changed, 692 insertions, 37 deletions

diff --git a/src/include/gc/mem.h b/src/include/gc/mem.h
new file mode 100644
index 0000000..2557289
--- /dev/null
+++ b/src/include/gc/mem.h
@@ -0,0 +1,9 @@
+#ifndef DEF_HEAP_H
+#define DEF_HEAP_H
+
+#include "gc/syscall.h"
+
+void* malloc(size_t size);
+void free(void* p);
+
+#endif
diff --git a/src/include/gc/obj.h b/src/include/gc/obj.h
new file mode 100644
index 0000000..10651f5
--- /dev/null
+++ b/src/include/gc/obj.h
@@ -0,0 +1,14 @@
+#ifndef DEF_OBJ_H
+#define DEF_OBJ_H
+
+// generic method error codes
+#define ME_UNHANDLED -32767
+#define ME_INTERRUPTED -32766
+
+struct object_cli {
+	int id;
+};
+
+typedef struct object_cli Object;
+
+#endif
diff --git a/src/include/gc/server.h b/src/include/gc/server.h
new file mode 100644
index 0000000..b98b4fb
--- /dev/null
+++ b/src/include/gc/server.h
@@ -0,0 +1,79 @@
+#ifndef DEF_SERVER_H
+#define DEF_SERVER_H
+
+#include "syscall.h"
+#include "obj.h"
+
+//parameter/return values types
+#define PT_VOID 0
+#define PT_OBJDESC 1
+#define PT_LONG 2
+#define PT_LONGLONG 3		//for return values
+#define PT_SHM 3	
+
+struct method_data {
+	struct {
+		union {
+			int i;
+			void* p;
+		} val;
+		int type;
+		int keepShm;		//for messages : keep shared memory segment after return or unmap ? (default : 0 = unmap)
+	} parameters[3];
+	uint32_t func;
+	int blocking;	//1 : blocking request, 0 : message
+	struct object_srv *obj;
+};
+
+struct method_ret {
+	union {
+		int i;
+		int64_t l;
+	};
+	int type;
+	int status;	//= error code if any
+};
+
+//helper function for creating return values
+struct method_ret mr_long(int val);
+struct method_ret mr_llong(int64_t val);
+struct method_ret mr_obj(Object* obj);
+struct method_ret mr_srv(struct object_srv* obj);
+struct method_ret mr_void();
+struct method_ret mr_err(int error);
+
+typedef struct method_ret (*method_handler)(struct method_data*);
+
+struct method_srv {
+	uint32_t id;
+	method_handler h;
+
+	struct method_srv *next;
+};
+
+struct object_srv {
+	int id;	//descriptor
+	struct method_srv *methods;
+
+	void *data;
+
+	struct object_srv *next;
+};
+
+typedef struct object_srv Server;
+
+extern Server procServer;	//corresponds to descriptor 0.
+
+//possible actions for srv_handle
+#define HA_ONCE 1	//check if requests are waiting, if so handle them
+#define HA_WAIT 2	//check if requests are waiting, if so handle them, else wait for one to come and handle it
+#define HA_LOOP 3	//wait for requests to come, handling them in an infinite loop
+
+void srv_handleAll();	//check all objects once
+void srv_handle(Server* o, int act);
+
+Server *srv_create();
+void srv_delete(Server *o);
+void srv_addHandler(Server* o, uint32_t method, method_handler h);
+
+#endif
diff --git a/src/include/gc/syscall.h b/src/include/gc/syscall.h
index 5287d85..f731e10 100644
--- a/src/include/gc/syscall.h
+++ b/src/include/gc/syscall.h
@@ -21,6 +21,7 @@ struct user_sendrequest {
 	uint32_t func, a, b, c;
 	uint32_t answeri;
 	int64_t answerll;
+	int errcode;
 };
 
 void thread_exit();
@@ -38,9 +39,10 @@ int object_owned(int descriptor);
 void object_close(int descriptor);
 int request_get(int descriptor, struct user_request *rq, int wait);
 int request_has(int descriptor);
-void request_answer(int descriptor, int answer1, int answer2);
+void request_answer(int descriptor, uint32_t answer1, uint32_t answer2, int errcode);
 int request_mapShm(int descriptor, size_t offset, int number);
 int request(int descriptor, struct user_sendrequest *rq);
 int send_msg(int descriptor, struct user_sendrequest *rq);
+int proc_setheap(size_t start, size_t end);
 
 #endif
diff --git a/src/include/gm/method.h b/src/include/gm/method.h
new file mode 100644
index 0000000..ac6ab0e
--- /dev/null
+++ b/src/include/gm/method.h
@@ -0,0 +1,22 @@
+#ifndef DEF_METHOD_H
+#define DEF_METHOD_H
+
+#define MP(r, a, b, c) (((r << 6) | (a << 4) | (b << 2) | c) << 24)
+
+/* 			****** FORMAT FOR #define NAMES : ******
+ *  	M_<method_name>_<ret><param1><param2><param3>
+ *  	where ret, param1, param2 and param3 are one of the following :
+ *  	- V (0) : nothing (void)
+ *  	- O (1) : object descriptor
+ *  	- I (2) : int
+ *  	- B (2) : int used as a boolean (0 = no, 1 = yes)
+ *  	- M (3) : shared memory, only for parameters
+ *  	- L (3) : int64 (long long), only for return values
+ */
+
+#define M_HANDLECHECK_BIVV	(1 | MP(2, 2, 0, 0))
+#define M_HANDLECHECK_BMIV	(1 | MP(2, 3, 2, 0))
+/* 	Checks if object handles that method. In case BIVV, only one method is checked for.
+ *  In case BMIV, the [b] methods in shared memory [a] are checked, first one not found returns false. */
+
+#endif
diff --git a/src/kernel/ipc/request.c b/src/kernel/ipc/request.c
index 9e42d6a..e59a66c 100644
--- a/src/kernel/ipc/request.c
+++ b/src/kernel/ipc/request.c
@@ -47,7 +47,7 @@ int request_has(int id) {
 	return 2;
 }
 
-void request_answer(int id, uint32_t answer, uint32_t answer2) {
+void request_answer(int id, uint32_t answer, uint32_t answer2, int errcode) {
 	int i;
 	//check if we own the object, if not return (also return if descriptor does not exist)
 	struct object *obj = objdesc_read(current_thread->process, id);
@@ -64,22 +64,27 @@ void request_answer(int id, uint32_t answer, uint32_t answer2) {
 	obj->request->acknowledged = RS_FINISHED;
 	switch (obj->request->func >> 30) {
 		case PT_OBJDESC:
-			if (obj->owner == obj->request->requester->process) {
+			if ((int)answer <= 0) {
 				obj->request->answer.n = answer;
 			} else {
-				int n = objdesc_get(obj->request->requester->process, objdesc_read(obj->owner, answer));
-				if (n == -1) {
-					n = objdesc_add(obj->request->requester->process, objdesc_read(obj->owner, answer));
+				if (obj->owner == obj->request->requester->process) {
+					obj->request->answer.n = answer;
+				} else {
+					int n = objdesc_get(obj->request->requester->process, objdesc_read(obj->owner, answer));
+					if (n == -1) {
+						n = objdesc_add(obj->request->requester->process, objdesc_read(obj->owner, answer));
+					}
+					obj->request->answer.n = n;
 				}
-				obj->request->answer.n = n;
 			}
 			break;
 		case PT_LONG:
 			obj->request->answer.n = answer;
 			break;
 		case PT_LONGLONG:
-			obj->request->answer.ll = (uint64_t)((uint64_t)answer << 32) | answer2;
+			obj->request->answer.ll = (uint64_t)((uint64_t)answer2 << 32) | answer;
 	}
+	obj->request->errcode = errcode;
 	//wake up receiver thread (thread_wakeUp)
 	thread_wakeUp(obj->request->requester);
 	//dereference request from object, unlock objects busymutex
@@ -150,15 +155,19 @@ static struct request *mkrequest(int id, struct thread *requester,
 		uint32_t v = (i == 0 ? a : (i == 1 ? b : c));
 		switch (n) {
 			case PT_OBJDESC:
-				if (obj->owner == current_thread->process) {
+				if ((int)v <= 0) {
 					rq->params[i] = v;
 				} else {
-					int d = objdesc_get(obj->owner, objdesc_read(current_thread->process, v));
-					if (d == -1) {
-						d = objdesc_add(obj->owner, objdesc_read(current_thread->process, v));
-						rq->obj_close[i] = d;
+					if (obj->owner == current_thread->process) {
+						rq->params[i] = v;
+					} else {
+						int d = objdesc_get(obj->owner, objdesc_read(current_thread->process, v));
+						if (d == -1) {
+							d = objdesc_add(obj->owner, objdesc_read(current_thread->process, v));
+							rq->obj_close[i] = d;
+						}
+						rq->params[i] = d;
 					}
-					rq->params[i] = d;
 				}
 				break;
 			case PT_LONG:
@@ -201,6 +210,7 @@ int request(int obj, uint32_t rq_ptr) {
 		case PT_LONGLONG:
 			urq->answerll = rq->answer.ll;
 	}
+	urq->errcode = rq->errcode;
 	kfree(rq);
 	return 0;
 }
diff --git a/src/kernel/ipc/request.h b/src/kernel/ipc/request.h
index 0b60a5c..0afc48b 100644
--- a/src/kernel/ipc/request.h
+++ b/src/kernel/ipc/request.h
@@ -24,6 +24,7 @@ struct request {
 		int64_t ll;
 		uint32_t n;
 	} answer;
+	int errcode;	//returned when function has finished
 };
 
 struct user_request {
@@ -35,12 +36,13 @@ struct user_sendrequest {
 	uint32_t func, a, b, c;
 	uint32_t answeri;
 	int64_t answerll;
+	int errcode;
 };
 
 //syscalls
 int request_get(int obj, uint32_t ptr, int wait);
 int request_has(int obj);
-void request_answer(int obj, uint32_t answer, uint32_t answer2);		//answer2 used for long long.
+void request_answer(int obj, uint32_t answer, uint32_t answer2, int errcode);		//answer2 used for long long.
 int request_mapShm(int obj, uint32_t pos, int number);
 
 int request(int obj, uint32_t rq_ptr);
diff --git a/src/kernel/linker/elf.c b/src/kernel/linker/elf.c
index bbf4906..6ad5d34 100644
--- a/src/kernel/linker/elf.c
+++ b/src/kernel/linker/elf.c
@@ -16,6 +16,8 @@ thread_entry elf_load(uint8_t *data, struct process* process) {
 	int i;
 	if (elf_check(data)) return 0;
 
+	struct page_directory *r = current_pagedir;
+	cli();
 	pagedir_switch(process->pagedir);
 
 	phdr = (struct elf_phdr*)((uint8_t*)(data + ehdr->e_phoff));
@@ -28,6 +30,10 @@ thread_entry elf_load(uint8_t *data, struct process* process) {
 			}
 		}
 	}
+
+	pagedir_switch(r);
+	sti();
+
 	return (thread_entry)ehdr->e_entry;
 }
 
diff --git a/src/kernel/mem/paging.c b/src/kernel/mem/paging.c
index 8996162..9972b2a 100644
--- a/src/kernel/mem/paging.c
+++ b/src/kernel/mem/paging.c
@@ -22,7 +22,6 @@ void frame_free(uint32_t id) {
 	bitset_clear(&frames, id);
 }
 
-
 void paging_init(size_t totalRam) {
 	uint32_t i;
 
diff --git a/src/kernel/mem/paging.h b/src/kernel/mem/paging.h
index cb76cd6..ec10560 100644
--- a/src/kernel/mem/paging.h
+++ b/src/kernel/mem/paging.h
@@ -26,7 +26,7 @@ struct page_directory {
 	struct segment_map *mappedSegs;
 };
 
-extern struct page_directory *kernel_pagedir;
+extern struct page_directory *kernel_pagedir, *current_pagedir;
 
 uint32_t frame_alloc();
 void frame_free(uint32_t id);
diff --git a/src/kernel/mem/seg.c b/src/kernel/mem/seg.c
index aa71564..ffaa84c 100644
--- a/src/kernel/mem/seg.c
+++ b/src/kernel/mem/seg.c
@@ -71,3 +71,24 @@ int simpleseg_handleFault(struct segment_map* sm, size_t addr, int write) {
 
 void simpleseg_delete(struct segment* seg) {
 }
+
+int simpleseg_resize(struct segment_map *map, size_t len) {
+	size_t i;
+
+	if (map == 0) return -1;
+	if (map->seg->delete != simpleseg_delete) return -2;
+
+	struct simpleseg *s = (struct simpleseg*)map->seg->seg_data;
+	if (len & 0xFFF) len = (len & 0xFFFFF000) + 0x1000;
+	if (len < map->len) {
+		for (i = map->start + len; i < map->start + map->len; i += 0x1000) {
+			page_unmapFree(pagedir_getPage(map->pagedir, i, 0));
+		}
+		map->len = len;
+		s->len = len;
+	} else if (len > map->len) {
+		map->len = len;
+		s->len = len;
+	}
+	return 0;
+}
diff --git a/src/kernel/mem/seg.h b/src/kernel/mem/seg.h
index 4d6660f..26664dc 100644
--- a/src/kernel/mem/seg.h
+++ b/src/kernel/mem/seg.h
@@ -37,5 +37,6 @@ struct segment_map* simpleseg_map(struct segment* seg, struct page_directory* pa
 void simpleseg_unmap(struct segment_map*);
 void simpleseg_delete(struct segment *seg);
 int simpleseg_handleFault(struct segment_map* map, size_t addr, int write);
+int simpleseg_resize(struct segment_map *map, size_t len);
 
 #endif
diff --git a/src/kernel/task/idt.h b/src/kernel/task/idt.h
index ed37eb0..b12d6c5 100644
--- a/src/kernel/task/idt.h
+++ b/src/kernel/task/idt.h
@@ -17,7 +17,6 @@ struct idt_ptr {
 } __attribute__((packed));
 
 struct registers {
-	uint32_t cr3;		//page directory physical address
 	uint32_t ds;                  // Data segment selector
 	uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; // Pushed by pusha.
 	uint32_t int_no, err_code;    // Interrupt number and error code (if applicable)
diff --git a/src/kernel/task/idt_.asm b/src/kernel/task/idt_.asm
index 1a594ca..95878c0 100644
--- a/src/kernel/task/idt_.asm
+++ b/src/kernel/task/idt_.asm
@@ -47,14 +47,8 @@ idt_flush:
    mov fs, ax
    mov gs, ax
 
-   mov eax, cr3
-   push eax
-
    call idt_%1Handler
    
-   pop eax
-   mov cr3, eax
-
    pop eax        ; reload the original data segment descriptor
    mov ds, ax
    mov es, ax
diff --git a/src/kernel/task/syscall.c b/src/kernel/task/syscall.c
index dd909e0..9a1ce81 100644
--- a/src/kernel/task/syscall.c
+++ b/src/kernel/task/syscall.c
@@ -31,6 +31,7 @@ CALL3V(request_answer, request_answer_sc);
 CALL3(request_mapShm, request_mapShm_sc);
 CALL2(request, request_sc);
 CALL2(send_msg, send_msg_sc);
+CALL2(process_setheapseg, proc_setheap_sc);
 
 static void thread_new_sc(struct registers* r) {
 	thread_new(current_thread->process, (thread_entry)r->ebx, (void*)r->ecx);
@@ -56,4 +57,5 @@ int_callback syscalls[] = {
 	request_mapShm_sc,
 	request_sc,
 	send_msg_sc,
+	proc_setheap_sc,
 	0 };
diff --git a/src/kernel/task/task.c b/src/kernel/task/task.c
index dec7565..9221813 100644
--- a/src/kernel/task/task.c
+++ b/src/kernel/task/task.c
@@ -77,6 +77,7 @@ void tasking_switch() {
 	}
 
 	current_thread = thread_next();
+	pagedir_switch(current_thread->process->pagedir);
 
 	gdt_setKernelStack(((uint32_t)current_thread->kernelStack_addr) + current_thread->kernelStack_size);
 
@@ -278,6 +279,7 @@ struct process *process_new(struct process* parent, uint32_t uid, uint32_t privi
 	p->pagedir = pagedir_new();
 	p->next = processes;
 	p->stacksBottom = 0xDF000000;
+	p->heapseg = 0;
 
 	p->next_objdesc = 0;
 	p->objects = 0;
@@ -289,6 +291,7 @@ struct process *process_new(struct process* parent, uint32_t uid, uint32_t privi
 
 static void thread_delete(struct thread *th) {
 	kfree(th->kernelStack_addr);
+	if (th->userStack_seg != 0) seg_unmap(th->userStack_seg);
 	th->process->threads--;
 	if (threads == th) {
 		threads = th->next;
@@ -319,3 +322,24 @@ static void process_delete(struct process *pr) {
 	}
 	kfree(pr);
 }
+
+int process_setheapseg(size_t start, size_t end) {		//syscall
+	struct process *p = current_thread->process;
+	if (start >= 0xE0000000 || end >= 0xE0000000) return -1;
+	if (p->heapseg == 0) {
+		struct segment *s = simpleseg_make(start, end - start, 1);
+		if (s == 0) return -5;
+		p->heapseg = seg_map(s, p->pagedir, 0);
+		if (p->heapseg == 0) return -1;
+		return 0;
+	} else if (p->heapseg->start != start) {
+		seg_unmap(p->heapseg);
+		struct segment *s = simpleseg_make(start, end - start, 1);
+		if (s == 0) return -5;
+		p->heapseg = seg_map(s, p->pagedir, 0);
+		if (p->heapseg == 0) return -1;
+		return 0;
+	} else {
+		return simpleseg_resize(p->heapseg, end - start);
+	}
+}
diff --git a/src/kernel/task/task.h b/src/kernel/task/task.h
index 1c22785..3dad63d 100644
--- a/src/kernel/task/task.h
+++ b/src/kernel/task/task.h
@@ -32,6 +32,8 @@ struct process {
 	struct obj_descriptor *objects;
 	uint32_t next_objdesc;
 
+	struct segment_map *heapseg;
+
 	struct process *next;	//Forms a linked list
 };
 
@@ -62,5 +64,6 @@ void thread_exit();
 void process_exit(uint32_t retval);
 struct thread * thread_new(struct process *proc, thread_entry entry_point, void *data);
 struct process* process_new(struct process *parent, uint32_t uid, uint32_t privilege);
+int process_setheapseg(size_t start, size_t end);	//syscall
 
 #endif
diff --git a/src/library/Makefile b/src/library/Makefile
index 74eb525..be5a76d 100644
--- a/src/library/Makefile
+++ b/src/library/Makefile
@@ -8,6 +8,8 @@ LDFLAGS = -r
 
 Library = grapes.o
 Objects = gc/syscall.o \
+		  gc/mem.o \
+		  gc/object.o \
 		  start.o
 
 all: $(Library)
diff --git a/src/library/gc/mem.c b/src/library/gc/mem.c
new file mode 100644
index 0000000..fe243ba
--- /dev/null
+++ b/src/library/gc/mem.c
@@ -0,0 +1,262 @@
+#include "gc/mem.h"
+
+struct heap_header {
+	uint32_t magic;
+	uint32_t is_hole;
+	size_t size;
+};
+
+struct heap_footer {
+	uint32_t magic;
+	struct heap_header *header;
+};
+
+struct heap {
+	struct heap_header **idx;
+	uint32_t idxused;
+	size_t start_addr, end_addr, max_end;
+};
+
+int heap_create(struct heap *heap, size_t start, size_t idxsize, size_t datasize, size_t maxdatasize);
+void* heap_alloc(struct heap *heap, size_t sz);
+void heap_free(struct heap *heap, void* ptr);
+
+#define HEAP_MAGIC 0xBAD0BEEF
+#define HEAP_MIN_SIZE 0x4000
+
+/* *******************			GENERAL MEMORY FUNCTIONS		******************** */
+
+static struct heap h;
+static int heap_ok = 0;
+
+void* malloc(size_t size) {
+	if (heap_ok == 0) {
+		if (heap_create(&h, 0x20000000, 0x00010000, 0x00100000, 0x4F000000)) return 0;
+		heap_ok = 1;
+	}
+	return heap_alloc(&h, size);
+}
+
+void free(void* p) {
+	if (heap_ok == 0 || (size_t)p < h.start_addr || (size_t)p > h.end_addr) return;
+	heap_free(&h, p);
+}
+
+static int setheapseg (struct heap *heap, size_t start, size_t end, size_t prev_end) {	//returns nonzero on error
+	if (heap == &h) {
+		return proc_setheap(start, end);
+	}	//otherwise, something else might be done.
+	return -1;
+}
+
+/* *******************			HEAP HEADER    	   ****************** */
+
+static void heapIdx_insert(struct heap *heap, struct heap_header *e) {
+	if ((heap->idxused + sizeof(struct heap_header*) + (size_t)heap->idx) >= heap->start_addr) return;
+
+	uint32_t iterator = 0, pos;
+	while (iterator < heap->idxused && heap->idx[iterator]->size < e->size) {
+		if (heap->idx[iterator] == e) return;
+		iterator++;
+	}
+	if (iterator == heap->idxused) {
+		heap->idx[heap->idxused++] = e;
+	} else {
+		pos = iterator;
+		iterator = heap->idxused;
+		while (iterator > pos) {
+			heap->idx[iterator] = heap->idx[iterator - 1];
+			iterator--;
+		}
+		heap->idxused++;
+		heap->idx[pos] = e;
+	}
+}
+
+static void heapIdx_remove(struct heap *heap, struct heap_header *e) {
+	uint32_t iterator;
+	for (iterator = 0; iterator < heap->idxused; iterator++) {
+		if (heap->idx[iterator] == e) break;
+	}
+	if (iterator == heap->idxused) return;
+	heap->idxused--;
+	while (iterator < heap->idxused) {
+		heap->idx[iterator] = heap->idx[iterator + 1];
+		iterator++;
+	}
+}
+
+/* ********************			HEAP CONTENTS		********************* */
+
+int heap_create(struct heap *heap, size_t start, size_t idxsize, size_t datasize, size_t maxdatasize) {
+	if (start & 0x0FFF) start = (start & 0xFFFFF000) + 0x1000;
+
+	heap->start_addr = start + idxsize;
+	heap->end_addr = start + idxsize + datasize;
+	heap->max_end = start + idxsize + maxdatasize;
+
+	if (setheapseg(heap, start, heap->end_addr, 0)) return -1;
+
+	heap->idx = (struct heap_header**)start;	
+	heap->idxused = 0;
+
+	struct heap_header *hole = (struct heap_header*) heap->start_addr;
+	hole->size = (heap->end_addr - heap->start_addr);
+	hole->magic = HEAP_MAGIC;
+	hole->is_hole = 1;
+
+	struct heap_footer *hole_footer = (struct heap_footer*)(heap->end_addr - sizeof(struct heap_footer));
+	hole_footer->header = hole;
+	hole_footer->magic = HEAP_MAGIC;
+
+	heapIdx_insert(heap, hole);
+	return 0;
+}
+
+static uint32_t heap_expand(struct heap *heap, size_t quantity) {
+	if (quantity & 0x0FFF) {
+		quantity = (quantity & 0xFFFFF000) + 0x1000;
+	}
+
+	if (heap->end_addr + quantity > heap->max_end) return 0;
+
+	size_t newEnd = heap->end_addr + quantity;
+
+	if (setheapseg(heap, (size_t)heap->idx, newEnd, heap->end_addr)) return 0;	//failed to bigger segment
+
+	struct heap_footer *last_footer = (struct heap_footer*)(heap->end_addr - sizeof(struct heap_footer));
+	struct heap_header *last_header = last_footer->header;
+	if (last_header->is_hole) {
+		heapIdx_remove(heap, last_header);
+		last_header->size += quantity;
+
+		last_footer = (struct heap_footer*)(newEnd - sizeof(struct heap_footer));
+		last_footer->magic = HEAP_MAGIC;
+		last_footer->header = last_header;
+
+		heapIdx_insert(heap, last_header);
+	} else {
+		last_header = (struct heap_header*)heap->end_addr;
+		last_footer = (struct heap_footer*)(newEnd - sizeof(struct heap_footer));
+
+		last_header->is_hole = 1;
+		last_header->magic = HEAP_MAGIC;
+		last_header->size = quantity;
+
+		last_footer->magic = HEAP_MAGIC;
+		last_footer->header = last_header;
+
+		heapIdx_insert(heap, last_header);
+	}
+
+	heap->end_addr = newEnd;
+
+	return 1;
+}
+
+static void heap_contract(struct heap *heap) {
+	struct heap_footer *last_footer = (struct heap_footer*)(heap->end_addr - sizeof(struct heap_footer));
+	struct heap_header *last_header = last_footer->header;
+
+	if (last_header->is_hole == 0) return;
+
+	size_t quantity = 0;
+	while ((heap->end_addr - heap->start_addr) - quantity > HEAP_MIN_SIZE &&
+			(last_header->size - quantity) > 0x1000)
+		quantity += 0x1000;
+	if (quantity == 0) return;
+
+	size_t newEnd = heap->end_addr - quantity;
+
+	if (setheapseg(heap, (size_t)heap->idx, newEnd, heap->end_addr)) return; //error ocurred
+
+	heapIdx_remove(heap, last_header);
+	last_header->size -= quantity;
+	last_footer = (struct heap_footer*)((size_t)last_footer - quantity);
+	last_footer->magic = HEAP_MAGIC;
+	last_footer->header = last_header;
+	heapIdx_insert(heap, last_header);
+
+	heap->end_addr = newEnd;
+}
+
+void* heap_alloc(struct heap *heap, size_t sz) {
+	size_t newsize = sz + sizeof(struct heap_header) + sizeof(struct heap_footer);
+	uint32_t iterator = 0;
+
+	while (iterator < heap->idxused) {
+		if (heap->idx[iterator]->size >= newsize) break;
+		iterator++;
+	}
+
+	if (iterator == heap->idxused) {	//No hole is big enough
+		if (heap_expand(heap, (sz & 0xFFFFF000) + 0x1000) == 0) return 0;	//FAILED
+		return heap_alloc(heap, sz);
+	}
+
+	struct heap_header *loc = heap->idx[iterator];
+	struct heap_footer *footer = (struct heap_footer*)((size_t)loc + loc->size - sizeof(struct heap_footer));
+	loc->is_hole = 0;
+	heapIdx_remove(heap, loc);
+	
+	//If we have enough space to create a USEFUL new hole next to the allocated block, do it.
+	//If we do not, we might return a block that is a few bytes bigger than neede.
+	if (loc->size > (newsize + sizeof(struct heap_header) + sizeof(struct heap_footer))) {
+		loc->size = newsize;
+
+		//Write footer for block we return
+		struct heap_footer *newfooter = (struct heap_footer*)((size_t)loc + newsize - sizeof(struct heap_footer));
+		newfooter->header = loc;
+		newfooter->magic = HEAP_MAGIC;
+
+		//Write header for new hole we create
+		struct heap_header *nextloc = (struct heap_header*)((size_t)loc + newsize);
+		nextloc->is_hole = 1;
+		nextloc->magic = HEAP_MAGIC;
+		nextloc->size = ((size_t)footer - (size_t)nextloc + sizeof(struct heap_footer));
+		footer->header = nextloc;	//Update footer
+		footer->magic = HEAP_MAGIC;
+
+		heapIdx_insert(heap, nextloc);
+	}
+
+	return (void*)((size_t)loc + sizeof(struct heap_header));
+}
+
+void heap_free(struct heap *heap, void* ptr) {
+	if (ptr == 0) return;
+	if ((size_t)ptr < heap->start_addr || (size_t)ptr > heap->end_addr) return;
+
+	struct heap_header *header = (struct heap_header*)((size_t)ptr - sizeof(struct heap_header));
+	struct heap_footer *footer = (struct heap_footer*)((size_t)header + header->size - sizeof(struct heap_footer));
+	if (header->magic != HEAP_MAGIC || footer->magic != HEAP_MAGIC) return;
+
+	//Unify left
+	struct heap_footer *prev_footer = (struct heap_footer*)((size_t)header - sizeof(struct heap_footer));
+	if (prev_footer->magic == HEAP_MAGIC && prev_footer->header->is_hole) {
+		header = prev_footer->header;
+		heapIdx_remove(heap, header);
+
+		footer->header = header;
+		header->size = ((size_t)footer - (size_t)header + sizeof(struct heap_footer));
+	}
+
+	//Unify right
+	struct heap_header *next_header = (struct heap_header*)((size_t)footer + sizeof(struct heap_footer));
+	if (next_header->magic == HEAP_MAGIC && next_header->is_hole) {
+		heapIdx_remove(heap, next_header);
+		footer = (struct heap_footer*)((size_t)footer + next_header->size);
+
+		footer->header = header;
+		header->size = ((size_t)footer - (size_t)header + sizeof(struct heap_footer));
+	}
+
+	header->is_hole = 1;
+
+	heapIdx_insert(heap, header);
+
+	if ((size_t)footer == (heap->end_addr - sizeof(struct heap_footer)) &&
+			header->size >= 0x2000 && (heap->end_addr - heap->start_addr > HEAP_MIN_SIZE)) {
+		heap_contract(heap);
+	}	
+}
diff --git a/src/library/gc/object.c b/src/library/gc/object.c
new file mode 100644
index 0000000..59b986b
--- /dev/null
+++ b/src/library/gc/object.c
@@ -0,0 +1,178 @@
+#include <gc/server.h>
+#include <gm/method.h>
+#include <gc/mem.h>
+
+Server procServer;
+static Server* servers = 0;
+
+static method_handler getHandler(Server *o, uint32_t m);
+static struct method_ret checkIfHandles(struct method_data *d);
+
+void objsrv_init() {
+	procServer.id = 0;
+	procServer.methods = 0;
+	procServer.next = 0;
+	procServer.data = 0;
+	servers = &procServer;
+	srv_addHandler(&procServer, M_HANDLECHECK_BIVV, checkIfHandles);
+}
+
+void srv_handleAll() {
+	Server *i = servers;
+	while (i) {
+		srv_handle(i, HA_ONCE);
+		i = i->next;
+	}
+}
+
+void srv_handle(Server *o, int act) {
+	int i;
+
+	if (act == HA_LOOP) {
+		while (1) srv_handle(o, HA_WAIT);
+	} else {
+		struct user_request rq;
+		int v = request_get(o->id, &rq, (act == HA_WAIT));
+		if (v == 0) {
+			method_handler m = getHandler(o, rq.func);
+			if (m == 0) {
+				if (rq.isBlocking) {
+					request_answer(o->id, 0, 0, ME_UNHANDLED);
+				}
+			} else {
+				struct method_data md;
+				md.func = rq.func;
+				md.blocking = rq.isBlocking;
+				md.obj = o;
+				//get parameters
+				for (i = 0; i < 3; i++) {
+					md.parameters[i].type = (rq.func >> (28 - (2 * i))) & 3;
+					switch (md.parameters[i].type) {
+						case PT_LONG:
+						case PT_OBJDESC:
+							md.parameters[i].val.i = rq.params[i];
+							break;
+						case PT_SHM:		//all the fuss about keepShm only applies to messages.
+							md.parameters[i].keepShm = 1;	//if local memory or if nothing, do not unmap it
+							if (rq.params[i] == 0) {	//TODO : map shm (shm manager) !!!
+								md.parameters[i].val.p = 0;
+								//md.parameters[i].keepShm = 0;	//we had to map it, so mark it to be unmapped
+							} else {
+								md.parameters[i].val.p = (void*)rq.params[i];
+							}
+							break;
+					}
+				}
+				
+				struct method_ret ret = m(&md);	//Call method
+				if (rq.isBlocking) {
+					uint32_t a = 0, b = 0;
+					if (ret.type == PT_OBJDESC || ret.type == PT_LONG) a = ret.i;
+					if (ret.type == PT_LONGLONG) a = (uint32_t)ret.l, b = (uint32_t)((uint64_t)ret.l >> 32);
+					request_answer(o->id, a, b, ret.status);
+				} else {
+					for (i = 0; i < 3; i++) {
+						if (md.parameters[i].type == PT_SHM && md.parameters[i].keepShm == 0) {
+							//TODO : unmap shm
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+void srv_addHandler(Server* o, uint32_t method, method_handler h) {
+	struct method_srv *s = malloc(sizeof(struct method_srv));
+	s->id = method;
+	s->h = h;
+	s->next = o->methods;
+	o->methods = s;
+}
+
+Server *srv_create() {
+	Server *s = malloc(sizeof(Server));
+	s->id = object_create();
+	s->methods = 0;
+	s->data = 0;
+	s->next = servers;
+	srv_addHandler(s, M_HANDLECHECK_BIVV, checkIfHandles);
+	servers = s;
+	return s;
+}
+
+void srv_delete(Server* s) {
+	//remove s from servers
+	if (servers == s) {
+		servers = s->next;
+	} else {
+		Server *i = servers;
+		while (i->next != 0) {
+			if (i->next == s) {
+				i->next = s->next;
+				break;
+			}
+			i = i->next;
+		}
+	}
+	//close s
+	object_close(s->id);
+	//free methods for s
+	while (s->methods != 0) {
+		struct method_srv *m = s->methods->next;
+		free(s->methods);
+		s->methods = m;
+	}
+	//free s
+	free(s);
+}
+
+// internal use
+
+method_handler getHandler(Server *o, uint32_t m) {
+	struct method_srv *i = o->methods;
+	while (i) {
+		if (i->id == m) return i->h;
+		i = i->next;
+	}
+	return 0;
+}
+
+struct method_ret checkIfHandles(struct method_data *d) {
+	if (getHandler(d->obj, d->parameters[0].val.i) == 0) {
+		return mr_long(0);
+	}
+	return mr_long(1);
+}
+
+// ***************************** HELPER FUNCTIONS FOR RETRUN VALUES
+
+struct method_ret mr_long(int val) {
+	struct method_ret r; r.status = 0; r.type = PT_LONG; r.i = val;
+	return r;
+}
+
+struct method_ret mr_llong(int64_t val) {
+	struct method_ret r; r.status = 0; r.type = PT_LONGLONG; r.l = val;
+	return r;
+}
+
+struct method_ret mr_obj(Object* obj) {
+	struct method_ret r; r.status = 0; r.type = PT_OBJDESC; r.i = obj->id;
+	return r;
+}
+
+struct method_ret mr_srv(Server* obj) {
+	struct method_ret r; r.status = 0; r.type = PT_OBJDESC; r.i = obj->id;
+	return r;
+}
+
+struct method_ret mr_void() {
+	struct method_ret r; r.status = 0; r.type = PT_VOID;
+	return r;
+}
+
+struct method_ret mr_err(int error) {
+	struct method_ret r; r.status = error; r.type = PT_VOID; r.l = 0;
+	return r;
+}
diff --git a/src/library/gc/syscall.c b/src/library/gc/syscall.c
index 8fd1554..e7d77a0 100644
--- a/src/library/gc/syscall.c
+++ b/src/library/gc/syscall.c
@@ -66,8 +66,8 @@ int request_has(int descriptor) {
 	return call(14, descriptor, 0, 0, 0, 0);
 }
 
-void request_answer(int descriptor, int answer1, int answer2) {
-	call(15, descriptor, answer1, answer2, 0, 0);
+void request_answer(int descriptor, uint32_t answer1, uint32_t answer2, int errcode) {
+	call(15, descriptor, answer1, answer2, errcode, 0);
 }
 
 int request_mapShm(int descriptor, size_t offset, int number) {
@@ -81,3 +81,7 @@ int request(int descriptor, struct user_sendrequest *rq) {
 int send_msg(int descriptor, struct user_sendrequest *rq) {
 	return call(18, descriptor, (size_t)rq, 0, 0, 0);
 }
+
+int proc_setheap(size_t start, size_t end) {
+	return call(19, start, end, 0, 0, 0);
+}
diff --git a/src/library/link.ld b/src/library/link.ld
index 17c944a..be5e028 100644
--- a/src/library/link.ld
+++ b/src/library/link.ld
@@ -2,7 +2,7 @@ ENTRY (start)
 INPUT (grapes.o)
  
 SECTIONS{
-    . = 0x10000000;
+    . = 0x100000;
  
     .text : {
         *(.text)
diff --git a/src/library/start.c b/src/library/start.c
index b3c5541..c9a7acc 100644
--- a/src/library/start.c
+++ b/src/library/start.c
@@ -3,6 +3,7 @@
 extern int main();
 
 void start() {
+	objsrv_init();
 	int ret = main();
 	process_exit(ret);
 }
diff --git a/src/modules/test/main.c b/src/modules/test/main.c
index df8b2ef..49dc50e 100644
--- a/src/modules/test/main.c
+++ b/src/modules/test/main.c
@@ -1,36 +1,57 @@
 #include <gc/syscall.h>
+#include <gc/mem.h>
+#include <gc/server.h>
 
 #define FACTOR 4
 
 int obj = -1;
 
+struct method_ret nulhandle(struct method_data *d) {
+	if (d->blocking) printk("[test:2?] Handling a request.\n");
+	else printk("[test:2?] Handling a message.\n");
+	return mr_void();
+}
+
 void thread2(void* d) {
 	printk("[test:2] Creating new object...\n");
-	obj = object_create();
-	struct user_request rq;
+	Server *s = srv_create();
+	srv_addHandler(s, 0x00000010, nulhandle);
+	obj = s->id;
 	while (1) {
 		printk("[test:2] Waiting for a request...\n");
-		request_get(obj, &rq, 1);
-		if (rq.isBlocking) {
-			printk("[test:2] Got request. Answering...\n");
-			request_answer(obj, 42, 0);
-		} else {
-			printk("[test:2] Got message. Ignoring it.\n");
-		}
+		srv_handle(s, HA_WAIT);
 	}
 }
 
 int main() {
+	int i;
+
 	printk("[test:1] Hi world !\n");
 	printk("[test:1] Creating new thread...\n");
 	thread_new(thread2, 0);
 	while (obj == -1);
 	printk("[test:1] Object was created. Sending request...\n");
 	struct user_sendrequest sr;
-	sr.func = 0x80000001;
+	sr.func = 0x00000010;
 	request(obj, &sr);
 	printk("[test:1] Got answer. Sending message...\n");
 	send_msg(obj, &sr);
+
+	printk("[test:1] testing malloc and free...");
+	int* v = malloc(10 * sizeof(int));
+	if (v == 0) printk("zero");
+	int* vv = malloc(10 * sizeof(int));
+	for (i = 0; i < 10; i++) { v[i] = i * 1243; }
+	for (i = 0; i < 10; i++) { vv[i] = i * 2; }
+	for (i = 0; i < 10; i++) {
+		if (v[i] != i * 1243) printk("FAIL");
+	}
+	for (i = 0; i < 10; i++) {
+		if (vv[i] != i * 2) printk("fail");
+	}
+	free(v); free(vv);
+	printk("nothing bad happened :)\n");
+
 	printk("[test:1] HAHA !!! Death in 10 seconds!\n");
 	thread_sleep(10000);
 	return 0;