wip: change memory to have access to page_tables and allocate these dynamically

headers/memory.h

@@ -13,7 +13,10 @@
 #define PD_SIZE    1024
 #define PAGE_MASK  0xFFFFF000
 #define HEAP_END   0xC0000000
+#define HEAP_START ((uint32_t) & _kernel_end - HEAP_END)
+#define PT_START   256
 
+extern uint32_t _kernel_end;
 extern uint32_t boot_page_directory;
 extern uint32_t *page_directory;
 extern uint32_t page_table_default[1024];
@@ -22,5 +25,7 @@ uint32_t *virt_to_phys(uint32_t *virt_addr);
 void init_memory(void);
 void *alloc_frames(size_t size);
 int free_frames(void *frame_ptr, size_t size);
-void *alloc_pages(size_t size, uint32_t **frame_ptr);
+void *alloc_pages(size_t size);
 int free_pages(void *page_ptr, size_t size);
+void init_page_table(uint32_t page_table[1024], uint16_t start);
+int16_t create_page_table(uint16_t pd_index);

src/kernel.c

@@ -36,8 +36,9 @@ void kernel_main(void)
 	        "I see no way to confuse an array of 256 seg:off pairs with a "
 	        "complex 8*unknown quantity -byte descriptor table. -- Troy "
 	        "Martin 03:50, 22 March 2009 (UTC)\n");
-	/* char *str = vmalloc(10); */
+	char *str = vmalloc(10);
-	/* strcpy(str, "hello"); */
+	if (str)
+		strcpy(str, "hello");
 	/* int i = 0; */
 	/* while (vmalloc(10)) */
 	/* 	; */
@@ -45,9 +46,9 @@ void kernel_main(void)
 	/* 	kprintf("%d\n", i); */
 	/* void *tab[1024]; */
 	/* for (int i = 0; i < 1023; i++) { */
-	/* 	tab[i] = alloc_pages(1); */
+	/* 	tab[i] = alloc_pages(1, NULL); */
-	/* PRINT_INT(i); */
+	/* 	PRINT_INT(i); */
-	/* PRINT_PTR(tab[i]); */
+	/* 	PRINT_PTR(tab[i]); */
 	/* 	if (!tab[i]) */
 	/* 		break; */
 	/* 	memset(tab[i], i, 4096); */
@@ -56,5 +57,5 @@ void kernel_main(void)
 	/* for (int i = 0; i < 10; i++) */
 	/* 	PRINT_UINT(((uint8_t *)tab[i])[0]); */
 	/* PRINT_PTR(tab[i]); */
-	/* shell_init(); */
+	shell_init();
 }

src/memory/frame.c

@@ -14,7 +14,10 @@ static uint32_t remaining_frames = MAX_FRAMES;
 
 static int32_t find_next_block(size_t nb_frames)
 {
-	for (uint32_t i = 1024; i + nb_frames < MAX_FRAMES - 1; i++) {
+	PRINT_UINT(CEIL(HEAP_START, PAGE_SIZE));
+	for (uint32_t i = CEIL(HEAP_START, PAGE_SIZE);
+	     i + nb_frames < MAX_FRAMES; i++) {
+		PRINT_UINT(i);
 		uint32_t j;
 		for (j = 0; frame_table[i + j] == 0 && j < nb_frames; j++)
 			;
@@ -33,9 +36,8 @@ void *alloc_frames(size_t size)
 		return NULL;
 	}
 	int i = find_next_block(nb_frames);
-	if (i == -1) {
+	if (i < 0) {
-		kprintf(KERN_WARNING "Not enough frames available\n",
+		kprintf(KERN_WARNING "Not enough frames available\n");
-		        MAX_FRAMES);
 		return NULL;
 	}
 	for (size_t j = 0; j < nb_frames; j++) {
@@ -44,7 +46,7 @@ void *alloc_frames(size_t size)
 	}
 	assert(remaining_frames >= nb_frames);
 	remaining_frames -= nb_frames;
-	return (void *)(i * PAGE_SIZE); // WARNING: address translation cramptés
+	return (void *)(i * PAGE_SIZE);
 }
 
 int free_frames(void *frame_ptr, size_t size)

src/memory/memory.c

@@ -7,24 +7,11 @@
 uint32_t *page_directory = &boot_page_directory;
 uint32_t page_table_default[1024] __attribute__((aligned(4096)));
 
-static void alloc_page_tables(void)
-{
-	uint32_t *frame_ptr = NULL;
-	for (int16_t i = 1; i < 768; i++) {
-		uint32_t *page_table = alloc_pages(PAGE_SIZE, &frame_ptr);
-		for (int16_t j = 0; j < 1024; j++)
-			page_table[j] = j << 12 | 0x03;
-		page_directory[i] = ((uint32_t)frame_ptr & PAGE_MASK) | 0x03;
-	}
-}
-
 void init_memory(void)
 {
 	assert(page_directory);
-	for (int16_t i = 0; i < 0x300; i++)
+	for (uint16_t i = 0; i < 0x300; i++)
 		page_directory[i] = 0x02;
-	for (int16_t i = 0; i < 1024; i++)
+	init_page_table(page_table_default, 0);
-		page_table_default[i] = (i << 12) | 0x03;
 	page_directory[0] = ((uint32_t)page_table_default - HEAP_END) | 0x03;
-	alloc_page_tables();
 }

src/memory/page.c

@@ -2,7 +2,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "debug.h"
 #include "kprintf.h"
 #include "memory.h"
 #include "utils.h"
@@ -10,12 +9,18 @@
 #define MAX_TLB_ENTRIES 32
 
 static uint32_t *current_page_table;
+static uint16_t current_pd_index;
 
 static int16_t find_next_block(size_t nb_pages)
 {
 	for (uint16_t pd_index = 0; pd_index < 768; pd_index++) {
+		if (page_directory[pd_index] == 0x02) {
+			if (create_page_table(pd_index) < 0)
+				return -2;
+		}
+		current_pd_index = pd_index;
 		current_page_table =
-		    (uint32_t *)(page_directory[pd_index] >> 12);
+		    (uint32_t *)((PT_START + pd_index) * PAGE_SIZE);
 		for (uint16_t i = 0; i + nb_pages < PT_SIZE; i++) {
 			uint16_t j;
 			for (j = 0; current_page_table[i + j] >> 12 == i + j &&
@@ -30,13 +35,14 @@ static int16_t find_next_block(size_t nb_pages)
 	return -1;
 }
 
-void *alloc_pages(size_t size, uint32_t **frame_ptr)
+void *alloc_pages(size_t size)
 {
 	const uint32_t nb_pages = CEIL(size, PAGE_SIZE);
 	const int16_t index = find_next_block(nb_pages);
 
 	if (index < 0) {
-		kprintf(KERN_CRIT "Not enough pages (max: %d)\n", PT_SIZE);
+		kprintf(KERN_CRIT "%d: Not enough pages (max: %d)\n", index,
+		        PT_SIZE);
 		return NULL;
 	}
 	for (size_t i = index; i - (size_t)index < nb_pages; i++) {
@@ -48,12 +54,10 @@ void *alloc_pages(size_t size, uint32_t **frame_ptr)
 				    PAGE_SIZE);
 			return NULL;
 		}
-		if (frame_ptr)
-			*frame_ptr = frame;
 		current_page_table[i] =
 		    ((uint32_t)frame & PAGE_MASK) | INIT_FLAGS;
 	}
-	return (void *)((0 * 1024 + index) * PAGE_SIZE);
+	return (void *)(((current_pd_index * 1024) + index) * PAGE_SIZE);
 }
 
 int free_pages(void *page_ptr, size_t size)

src/memory/page_table.c

@@ -0,0 +1,18 @@
+#include "memory.h"
+
+void init_page_table(uint32_t page_table[1024], uint16_t start)
+{
+	for (uint16_t i = start; i < 1024; i++)
+		page_table[i] = (i << 12) | 0x03;
+}
+
+int16_t create_page_table(uint16_t pd_index)
+{
+	void *frame = alloc_frames(PAGE_SIZE);
+	if (!frame)
+		return -1;
+	page_directory[pd_index] = ((uint32_t)frame & PAGE_MASK) | 0x03;
+	uint32_t *page_table = (uint32_t *)((PT_START + pd_index) * PAGE_SIZE);
+	init_page_table(page_table, 0);
+	return 0;
+}

src/memory/virt/allocator.c

@@ -49,7 +49,7 @@ static void new_block(Zone *zone, uint32_t zone_size)
 
 int new_vzone(block_type_t type, uint32_t size)
 {
-	void *heap = alloc_pages(size, NULL);
+	void *heap = alloc_pages(size);
 	if (heap == NULL) {
 		kprintf(KERN_ERR "error: alloc_pages failed\n");
 		return (-1);