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fix: add_frame_node: map enough page to write frame metadata

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Starnakin
2025-11-28 16:21:28 +01:00
parent 5591120deb
commit 99ee5b8cec
1 changed files with 37 additions and 31 deletions
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68
src/memory/memory.c
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@ -21,19 +21,19 @@ static void lst_add_back(struct frame_zone **root, struct frame_zone *element)
it->next = element;
}
static void add_frame_node(multiboot_memory_map_t *mmmt)
{
static uint32_t index;
uint32_t *pd = &boot_page_directory;
static uint32_t index = 0;
/**
* # = kernel code
* - = blank
*/
uint32_t start_addr = mmmt->addr;
uint32_t end_addr = mmmt->addr + mmmt->len;
uint32_t len = mmmt->len;
uint64_t start_addr = mmmt->addr;
uint64_t end_addr = mmmt->addr + mmmt->len;
uint64_t len = mmmt->len;
/** Kernel code cover all the block
* this situation:
@ -60,53 +60,60 @@ static void add_frame_node(multiboot_memory_map_t *mmmt)
}
end_addr = ROUND_CEIL(start_addr + len, PAGE_SIZE);
pd[PDE_FRAME_ZONES] =
PD[PDE_FRAME_ZONES] =
((uint32_t)frame_zones_page_table - VIRT_OFFSET) | INIT_FLAGS;
frame_zones_page_table[index] =
((uint32_t)start_addr & PAGE_MASK) | INIT_FLAGS;
/** We need to determine how many frames are available
to save how many frame the blocks contain etc we need some meta data
1 struct frame_zone and a frame_table, the size of the frame_table is 1 bit per frame
the frame_table is a uint8_t so 8 bit, so its size must be CEIL(max_frames, 8)
But we don't have max_frames.
We can determine max_frame = (block_len - sizeof(struct frame_zone)) / (PAGE_SIZE + 1 / 8) (1 / 8 because size is in byte but we only need one bit)
Because we don't use float we can't have 1 / 8
So we will multiplicate every members of this equation by 8 to have only complet number
So... max_frame = (block_len - sizeof(struct frame_zone)) * 8 / (PAGE_SIZE * 8 + 1)
*/
const uint32_t nb_frame = (len - sizeof(struct frame_zone)) * 8 / (PAGE_SIZE * 8 + 1);
const uint32_t frame_table_size = CEIL(nb_frame, (sizeof(uint8_t) * 8));
uint32_t page_needed = CEIL(frame_table_size + sizeof(struct frame_zone), PAGE_SIZE);
uint32_t i = 0;
for (; i < page_needed; i++)
frame_zones_page_table[index + i] = (((uint32_t)start_addr + i * PAGE_SIZE) & PAGE_MASK) | INIT_FLAGS;
struct frame_zone *current =
(struct frame_zone *)PTE2VA(PDE_FRAME_ZONES, index++);
(struct frame_zone *)PTE2VA(PDE_FRAME_ZONES, index);
current->frame_table = (uint8_t *)current + sizeof(struct frame_zone);
current->frame_table = (uint8_t*) ((uint32_t) current + sizeof(struct frame_zone));
/** 8 is cause we are using uint8_t
nb_frame = size / (PAGE_SIZE + 1 / 8)
cause we are using non decimal number
nb_frame = ((size * 8) / (PAGE_SIZE * 8 + 1))
*/
const uint32_t nb_frame = ((len * 8) / (PAGE_SIZE * 8 + 1));
current->first_free_frame = 0;
current->next = NULL;
current->remaining_frames = nb_frame;
current->total_frames = nb_frame;
current->addr = (void*)(uint32_t)start_addr + page_needed * PAGE_SIZE;
memset(current->frame_table, 0,
nb_frame * sizeof(*current->frame_table));
bzero(current->frame_table, frame_table_size);
uint32_t i = 1;
for (; i < CEIL(nb_frame, PAGE_SIZE); i++)
frame_zones_page_table[index + i] =
((uint32_t)(start_addr + i * PAGE_SIZE) & PAGE_MASK) |
INIT_FLAGS;
current->addr = (void *)(start_addr + i * PAGE_SIZE);
index += i - 1;
index += i;
lst_add_back(&head, current);
}
static void init_frame_zones(void)
{
for (uint32_t i = 0; i < mmap_length; i++) {
multiboot_memory_map_t *mmmt =
(multiboot_memory_map_t *)mmap_addr + i;
for(uint32_t i = 0; i < mmap_length;
i += sizeof(multiboot_memory_map_t))
{
multiboot_memory_map_t* mmmt =
(multiboot_memory_map_t*) ((uint32_t)mmap_addr + i);
if (mmmt->type == MULTIBOOT_MEMORY_AVAILABLE)
add_frame_node(mmmt);
}
}
void init_memory(multiboot_info_t *mbd, uint32_t magic)
void init_memory()
{
init_multiboot(mbd, magic);
init_frame_zones();
// initialize all the PTs
for (uint16_t i = KERNEL_PT_START; i < KERNEL_PT_END; i++) {
@ -115,7 +122,6 @@ void init_memory(multiboot_info_t *mbd, uint32_t magic)
kpanic("Couldn't initialize kernel PTs\n");
PD[i] = frame | RW;
}
PD[1023] = ((uint32_t)&boot_page_directory - VIRT_OFFSET) | INIT_FLAGS;
// kalash kalash kalash sur la mélodie chez nous pas de félonie ça vient
// de Sevran les R
}