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memory works

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This commit is contained in:
Freya Murphy 2024-01-29 13:22:50 -05:00
parent 175e5b55b8
commit e71a141533
Signed by: freya
GPG key ID: 744AB800E383AE52
10 changed files with 132 additions and 96 deletions
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2
Makefile
View file

@ -47,4 +47,4 @@ $(BUILD_DIR)/$(ISO_NAME): $(BUILD_DIR)/$(K_BIN_NAME) grub.cfg
grub-mkrescue -o $(BUILD_DIR)/$(ISO_NAME) $(BUILD_DIR)/iso grub-mkrescue -o $(BUILD_DIR)/$(ISO_NAME) $(BUILD_DIR)/iso
run: all run: all
qemu-system-x86_64 $(BUILD_DIR)/$(ISO_NAME) -serial stdio qemu-system-x86_64 $(BUILD_DIR)/$(ISO_NAME) -serial stdio -m 4G

37
src/arch/amd64/boot.S
View file

@ -1,9 +1,10 @@
global start global start
global pml4_list global kernel_pml4
global init_pdpt global kernel_pdpt_0
global init_pd global kernel_pd_0
global init_pt global kernel_pt_0
global paging_pt global paging_pt
global bootstrap_pt
extern kmain extern kmain
extern amd64_shim extern amd64_shim
bits 32 bits 32
@ -25,15 +26,17 @@ mb_end:
section .bss section .bss
align 4096 align 4096
pml4_list: ; reserve memory for initial 512 pml4 entires kernel_pml4: ; reserve memory for initial 512 pml4 entires
resb 4096 resb 4096
init_pdpt: ; reserve memory for initial 512 pdpt entires kernel_pdpt_0: ; reserve memory for initial 512 pdpt entires
resb 4096 resb 4096
init_pd: ; reserve memory for initial 512 pd entries kernel_pd_0: ; reserve memory for initial 512 pd entries
resb 4096 resb 4096
init_pt: ; reserve memory for initial 512 pt entries kernel_pt_0: ; reserve memory for initial 512 pt entries
resb 4096 resb 4096
paging_pt: ; reserve memory for 512 paging reserved pt entires paging_pt: ; reserve pages for pager mappings
resb 4096
bootstrap_pt: ; reserve pages to bootstrap pager
resb 4096 resb 4096
align 16 align 16
@ -85,6 +88,7 @@ start:
mov esp, stack_end mov esp, stack_end
mov ebp, stack_end mov ebp, stack_end
push DWORD 0
push ebx push ebx
mov edi, 0x1000 mov edi, 0x1000
@ -93,13 +97,13 @@ start:
mov ecx, 4096 mov ecx, 4096
rep stosd rep stosd
mov edi, cr3 mov edi, cr3
; FIXME: Update boot.S to point base of paging to pml4e_list, see above
mov DWORD [edi], 0x2003 ; Set the uint32_t at the destination index to 0x2003. mov DWORD [edi], kernel_pdpt_0 + 3 ; Set the uint32_t at the destination index to 0x2003.
add edi, 0x1000 ; Add 0x1000 to the destination index. mov edi, kernel_pdpt_0 ; Add 0x1000 to the destination index.
mov DWORD [edi], 0x3003 ; Set the uint32_t at the destination index to 0x3003. mov DWORD [edi], kernel_pd_0 + 3 ; Set the uint32_t at the destination index to 0x3003.
add edi, 0x1000 ; Add 0x1000 to the destination index. mov edi, kernel_pd_0 ; Add 0x1000 to the destination index.
mov DWORD [edi], 0x4003 ; Set the uint32_t at the destination index to 0x4003. mov DWORD [edi], kernel_pt_0 + 3 ; Set the uint32_t at the destination index to 0x4003.
add edi, 0x1000 ; Add 0x1000 to the destination index. mov edi, kernel_pt_0 ; Add 0x1000 to the destination index.
mov ebx, 0x00000003 ; Set the B-register to 0x00000003. mov ebx, 0x00000003 ; Set the B-register to 0x00000003.
mov ecx, 512 ; Set the C-register to 512. mov ecx, 512 ; Set the C-register to 512.
@ -132,6 +136,7 @@ start:
bits 64 bits 64
code64: code64:
pop rdi
call amd64_shim call amd64_shim
mov rdi, rax mov rdi, rax
call kmain call kmain

26
src/arch/amd64/mboot.c
View file

@ -1,24 +1,28 @@
#include "mboot.h" #include "mboot.h"
#include "serial.h"
#include <stddef.h> #include <stddef.h>
#include <lib.h> #include <lib.h>
static void read_cmdline(struct mboot_info *info, struct mboot_tag *tag, char *data, uint8_t len) { static void read_cmdline(struct mboot_tag *tag, char *data, uint8_t len) {
if (len >= CMDLINE_MAX) if (len >= CMDLINE_MAX)
len = CMDLINE_MAX; // truncate :( len = CMDLINE_MAX; // truncate :(
memcpy(tag->data.cmdline, data, len); memcpy(tag->data.cmdline, data, len);
tag->data.cmdline[len] = '\0'; tag->data.cmdline[len] = '\0';
info->tags[MBOOT_CMDLINE] = *tag;
} }
static void read_xsdp(struct mboot_info *info, struct mboot_tag *tag, char *data) { static void read_memorymap(struct mboot_tag *tag, uint64_t size, uint32_t *data) {
tag->data.memory_map = (struct memory_map *) data;
tag->data.memory_map->size = size;
}
static void read_xsdp(struct mboot_tag *tag, char *data) {
tag->data.rootsdp = (void *) data; tag->data.rootsdp = (void *) data;
info->tags[MBOOT_XSDP] = *tag;
} }
static uint32_t *read_tag(struct mboot_info *info, uint32_t *data) { static uint32_t *read_tag(struct mboot_info *info, uint32_t *data) {
struct mboot_tag tag; struct mboot_tag tag;
tag.type = ((uint16_t*)data)[0]; tag.type = *((uint16_t *)data);
tag.size = data[1]; tag.size = data[1];
tag.valid = 1; tag.valid = 1;
@ -26,15 +30,20 @@ static uint32_t *read_tag(struct mboot_info *info, uint32_t *data) {
switch (tag.type) { switch (tag.type) {
case MBOOT_CMDLINE: case MBOOT_CMDLINE:
read_cmdline(info, &tag, (char *)(data + 2), data_len); read_cmdline(&tag, (char *)(data + 2), data_len);
break;
case MBOOT_MEMORYMAP:
read_memorymap(&tag, tag.size, data + 2);
break; break;
case MBOOT_XSDP: case MBOOT_XSDP:
read_xsdp(info, &tag, (char *) (data + 2)); read_xsdp(&tag, (char *) (data + 2));
break; break;
default: default:
break; break;
} }
info->tags[tag.type] = tag;
if(tag.size % 8 != 0) { if(tag.size % 8 != 0) {
tag.size += 8 - (tag.size % 8); tag.size += 8 - (tag.size % 8);
} }
@ -42,12 +51,13 @@ static uint32_t *read_tag(struct mboot_info *info, uint32_t *data) {
return data + tag.size / sizeof(uint32_t); return data + tag.size / sizeof(uint32_t);
} }
struct mboot_info mboot_load_info(void *mboot_info) { struct mboot_info mboot_load_info(const void *mboot_info) {
struct mboot_info info = {0}; struct mboot_info info = {0};
uint32_t* data = (uint32_t*) mboot_info; uint32_t* data = (uint32_t*) mboot_info;
info.total_size = *data++; info.total_size = *data++;
info.reserved = *data++; info.reserved = *data++;
while((uint8_t*) data < (uint8_t*) mboot_info + info.total_size) { while((uint8_t*) data < (uint8_t*) mboot_info + info.total_size) {
data = read_tag(&info, data); data = read_tag(&info, data);

4
src/arch/amd64/mboot.h
View file

@ -25,14 +25,14 @@ enum mboot_tag_type {
struct mboot_info { struct mboot_info {
uint32_t total_size; uint32_t total_size;
uint32_t reserved; uint32_t reserved;
struct mboot_tag tags[21]; struct mboot_tag tags[22];
}; };
/** /**
* Loads the multi boot information * Loads the multi boot information
* @param mboot_info - the pointer passed from multiboot2 * @param mboot_info - the pointer passed from multiboot2
*/ */
struct mboot_info mboot_load_info(void *mboot_info); struct mboot_info mboot_load_info(const void *mboot_info);
/** /**
* Gets a tag from multiboot * Gets a tag from multiboot

85
src/arch/amd64/paging.c
View file

@ -7,18 +7,9 @@
#include <memory/physalloc.h> #include <memory/physalloc.h>
#include <memory/virtalloc.h> #include <memory/virtalloc.h>
#include "paging.h"
#include "bindings.h" #include "bindings.h"
#define F_PRESENT 0x001
#define F_WRITEABLE 0x002
#define F_UNPRIVILEGED 0x004
#define F_WRITETHROUGH 0x008
#define F_CACHEDISABLE 0x010
#define F_ACCESSED 0x020
#define F_DIRTY 0x040
#define F_MEGABYTE 0x080
#define F_GLOBAL 0x100
// PAGE MAP LEVEL 4 ENTRY // PAGE MAP LEVEL 4 ENTRY
struct pml4e { struct pml4e {
uint64_t flags : 6; uint64_t flags : 6;
@ -61,19 +52,19 @@ struct pte {
}; };
// bss segment, can write to // bss segment, can write to
extern struct pml4e pml4_list[512]; extern struct pml4e kernel_pml4[512];
extern struct pdpte init_pdpt[512]; extern struct pdpte kernel_pdpt_0[512];
extern struct pde init_pd[512]; extern struct pde kernel_pd_0[512];
extern struct pte init_pt[512]; extern struct pte bootstrap_pt[512];
extern struct pte paging_pt[512]; // paging_pt should NEVER be outside of this file, NEVER i say extern struct pte paging_pt[512]; // paging_pt should NEVER be outside of this file, NEVER i say
// paged address to read page tables // paged address to read page tables
// the structures are not gurenteed to be ident mapped // the structures are not gurenteed to be ident mapped
// map them here with map_<type>(phys_addr) before useing structures // map them here with map_<type>(phys_addr) before useing structures
static struct pdpte *pdpt_mapped = (void *) (uintptr_t) 0x1000; static struct pdpte *pdpt_mapped = (void *) (uintptr_t) 0x201000;
static struct pdpte *pd_mapped = (void *) (uintptr_t) 0x2000; static struct pdpte *pd_mapped = (void *) (uintptr_t) 0x202000;
static struct pdpte *pt_mapped = (void *) (uintptr_t) 0x3000; static struct pdpte *pt_mapped = (void *) (uintptr_t) 0x203000;
void *addr_mapped = (void *) (uintptr_t) 0x4000; void *addr_mapped = (void *) (uintptr_t) 0x204000;
static inline void invlpg(void *addr) { static inline void invlpg(void *addr) {
__asm volatile("invlpg (%0)" ::"r" (addr) : "memory"); __asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
@ -172,6 +163,7 @@ int map_page(struct pml4e *pml4, void *virt_addr, void *phys_addr, unsigned int
map_pt(__pt); map_pt(__pt);
pt_mapped[pt_offset].flags = F_PRESENT | flags; pt_mapped[pt_offset].flags = F_PRESENT | flags;
pt_mapped[pt_offset].address = (((uint64_t)phys_addr) >> 12); pt_mapped[pt_offset].address = (((uint64_t)phys_addr) >> 12);
invlpg(virt_addr); invlpg(virt_addr);
return 0; return 0;
} }
@ -236,51 +228,52 @@ done:
} }
void paging_init(void) { void paging_init(void) {
memset(pml4_list, 0, 4096);
pml4_list[0].flags = F_PRESENT | F_WRITEABLE; kernel_pml4[0].flags = F_PRESENT | F_WRITEABLE;
pml4_list[0].address = (uint64_t)init_pdpt >> 12; kernel_pml4[0].address = (uint64_t)(&kernel_pdpt_0) >> 12;
kernel_pdpt_0[0].flags = F_PRESENT | F_WRITEABLE;
kernel_pdpt_0[0].address = (uint64_t)(&kernel_pd_0) >> 12;
kernel_pd_0[1].flags = F_PRESENT | F_WRITEABLE;
kernel_pd_0[1].address = (uint64_t)(&paging_pt) >> 12;
kernel_pd_0[2].flags = F_PRESENT | F_WRITEABLE;
kernel_pd_0[2].address = (uint64_t)(&bootstrap_pt) >> 12;
memset(init_pdpt, 0, 4096); memset(&paging_pt, 0, 4096);
init_pdpt[0].flags = F_PRESENT | F_WRITEABLE; memset(&bootstrap_pt, 0, 4096);
init_pdpt[0].address = (uint64_t)init_pd >> 12;
memset(pml4_list, 0, 4096);
init_pd[0].flags = F_PRESENT | F_WRITEABLE;
init_pd[0].address = (uint64_t)paging_pt >> 12;
init_pd[1].flags = F_PRESENT | F_WRITEABLE;
init_pd[1].address = (uint64_t)init_pt >> 12;
memset(init_pt, 0, 4096);
memset(paging_pt, 0, 4096);
} }
static inline void *page_align(void *addr) { static inline void *page_align(void *addr) {
uintptr_t a = (uintptr_t) addr; uintptr_t a = (uintptr_t) addr;
a += PAGE_SIZE + 1; a += PAGE_SIZE - 1;
a /= PAGE_SIZE; a /= PAGE_SIZE;
a *= PAGE_SIZE;
return (void *) a; return (void *) a;
} }
void *mmap(void *addr, size_t len) { void *mmap(void *addr, size_t len) {
len += (uintptr_t)addr % PAGE_SIZE; len += (long)addr % PAGE_SIZE;
int pages = (len + PAGE_SIZE - 1) / PAGE_SIZE; long pages = (len + PAGE_SIZE - 1) / PAGE_SIZE;
void *virt = virtaddr_alloc(pages); void *virt = virtaddr_alloc(pages);
if (virt == NULL) if (virt == NULL) {
return NULL; return NULL;
}
void *phys = page_align(addr); void *phys = page_align(addr);
for (long i = 0; i < pages; i++) { for (long i = 0; i < pages; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE); void *virt_temp = (char *)virt + (i * PAGE_SIZE);
void *phys_temp = (char *)phys + (i * PAGE_SIZE); void *phys_temp = (char *)phys + (i * PAGE_SIZE);
map_page(pml4_list, virt_temp, phys_temp, F_WRITEABLE); map_page(kernel_pml4, virt_temp, phys_temp, F_WRITEABLE);
} }
return addr; map_page(kernel_pml4, virt, (void*)0x23443, F_WRITEABLE);
return virt;
} }
void unmap(void *addr) { void unmap(void *addr) {
long pages = virtaddr_free(addr); long pages = virtaddr_free(addr);
for (long i = 0; i < pages; i++) { for (long i = 0; i < pages; i++) {
void *virt = (char *)addr + (i * PAGE_SIZE); void *virt = (char *)addr + (i * PAGE_SIZE);
unmap_page(pml4_list, virt); unmap_page(kernel_pml4, virt);
} }
} }
@ -296,7 +289,7 @@ void *alloc_pages(int count) {
for (int i = 0; i < count; i++) { for (int i = 0; i < count; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE); void *virt_temp = (char *)virt + (i * PAGE_SIZE);
void *phys_temp = (char *)phys + (i * PAGE_SIZE); void *phys_temp = (char *)phys + (i * PAGE_SIZE);
map_page(pml4_list, virt_temp, phys_temp, F_WRITEABLE); map_page(kernel_pml4, virt_temp, phys_temp, F_WRITEABLE);
} }
return virt; return virt;
} }
@ -307,7 +300,7 @@ void free_page(void *virt) {
return; return;
for (long i = 0; i < pages; i++) { for (long i = 0; i < pages; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE); void *virt_temp = (char *)virt + (i * PAGE_SIZE);
unmap_page(pml4_list, virt_temp); unmap_page(kernel_pml4, virt_temp);
} }
} }
@ -318,3 +311,11 @@ void memory_lock(void) {
void memory_unlock(void) { void memory_unlock(void) {
sti(); sti();
} }
int kmap_page(void *virt_addr, void *phys_addr, unsigned int flags) {
return map_page(kernel_pml4, virt_addr, phys_addr, flags);
}
int kunmap_page(void *virt_addr) {
return unmap_page(kernel_pml4, virt_addr);
}

16
src/arch/amd64/paging.h Normal file
View file

@ -0,0 +1,16 @@
#pragma once
#define F_PRESENT 0x001
#define F_WRITEABLE 0x002
#define F_UNPRIVILEGED 0x004
#define F_WRITETHROUGH 0x008
#define F_CACHEDISABLE 0x010
#define F_ACCESSED 0x020
#define F_DIRTY 0x040
#define F_MEGABYTE 0x080
#define F_GLOBAL 0x100
int kmap_page(void *virt_addr, void *phys_addr, unsigned int flags);
int kunmap_page(void *virt_addr);
void paging_init(void);

16
src/arch/amd64/shim.c
View file

@ -4,23 +4,17 @@
#include <shim.h> #include <shim.h>
#include <memory.h> #include <memory.h>
#include "paging.h"
#include "mboot.h" #include "mboot.h"
static struct boot_info boot_info; static struct boot_info boot_info;
// entry point for amd64 // entry point for amd64
void* amd64_shim(void *mboot_data_ptr) { void* amd64_shim(void *mboot_data_ptr) {
//struct pml4e *pml4 = (struct pml4e *)0x1000; serial_init();
//struct pdpte *pdpt = (struct pdpte *)0x2000; paging_init();
//struct pde *pd = (struct pde *)0x3000;
//struct pte *pt = (struct pte *)0x4000; kmap_page(mboot_data_ptr, mboot_data_ptr, F_WRITEABLE);
//pd[1].flags = F_PRESENT | F_WRITEABLE;
//pd[1].address = ((uint64_t)pt) >> 12;
//map_page(pml4, (void *)0x80000000, (void *)0xB8002, F_WRITEABLE);
//__asm("invlpg 0x200000");
//void *ret;
//find_phys_addr(pml4, (void *)0x80000000, &ret);
//return ret;
struct mboot_info mboot_info; struct mboot_info mboot_info;
mboot_info = mboot_load_info(mboot_data_ptr); mboot_info = mboot_load_info(mboot_data_ptr);

1
src/kmain.c
View file

@ -10,6 +10,7 @@ void kmain(struct boot_info *info) {
memory_init(info->map); memory_init(info->map);
//*(char*)(0xB8002 + 0x20'0000) = 'd'; //*(char*)(0xB8002 + 0x20'0000) = 'd';
itoa((long)info, buf, 16); itoa((long)info, buf, 16);
itoa(*(long*)info, buf, 16);
//fb_init(1024, 768); //fb_init(1024, 768);
serial_out_str(buf); serial_out_str(buf);
} }

23
src/memory/physalloc.c
View file

@ -7,8 +7,9 @@
#include <memory/physalloc.h> #include <memory/physalloc.h>
#include <memory/virtalloc.h> #include <memory/virtalloc.h>
extern uintptr_t kernel_start; extern char kernel_start;
extern uintptr_t kernel_end; extern char kernel_end;
#define kaddr(addr) ((uintptr_t)(&addr))
// between memory_start and kernel_start will be the bitmap // between memory_start and kernel_start will be the bitmap
static uintptr_t memory_start = 0; static uintptr_t memory_start = 0;
@ -113,9 +114,9 @@ void free_phys_pages(void *ptr, int pages) {
static bool segment_invalid(const struct memory_segment *segment) { static bool segment_invalid(const struct memory_segment *segment) {
if (segment->type != 1) return false; if (segment->type != 1) return false;
if (segment->addr < kernel_start) return false; if (segment->addr < kaddr(kernel_start)) return false;
if (segment->addr + segment->len < memory_start) return false; if (segment->addr + segment->len < memory_start) return false;
if (segment->addr + segment->len < kernel_start) return false; if (segment->addr + segment->len < kaddr(kernel_start)) return false;
return true; return true;
} }
@ -127,7 +128,7 @@ static struct memory_area segment_to_area(const struct memory_segment *segment)
if (memory_start) if (memory_start)
start = memory_start; start = memory_start;
else else
start = kernel_end; start = kaddr(kernel_end);
if (segment->addr < start) { if (segment->addr < start) {
addr = start; addr = start;
@ -144,7 +145,7 @@ static struct memory_area segment_to_area(const struct memory_segment *segment)
} }
static uintptr_t page_align(uintptr_t ptr) { static uintptr_t page_align(uintptr_t ptr) {
return ptr + PAGE_SIZE - 1 / PAGE_SIZE; return (ptr + PAGE_SIZE - 1) / PAGE_SIZE * PAGE_SIZE;
} }
void memory_init(struct memory_map *map) { void memory_init(struct memory_map *map) {
@ -165,7 +166,7 @@ void memory_init(struct memory_map *map) {
struct memory_segment *segment = &map->entries[0]; struct memory_segment *segment = &map->entries[0];
int segment_count = 0; int segment_count = 0;
for(; (uintptr_t) segment < end; segment++) { for(; (uintptr_t) segment < end; segment++) {
if (segment_invalid(segment)) if (segment_invalid(segment))
continue; continue;
@ -180,15 +181,17 @@ void memory_init(struct memory_map *map) {
//HACK: terrible hack bad bad bad bad //HACK: terrible hack bad bad bad bad
long bitmap_size = bitmap_pages * PAGE_SIZE; long bitmap_size = bitmap_pages * PAGE_SIZE;
bitmap = (uint64_t *) page_at(page_count - bitmap_pages); bitmap = (uint64_t *) page_align(kaddr(kernel_end));
char buf[20];
long page_area_size = segment_count * sizeof(struct memory_area); long page_area_size = segment_count * sizeof(struct memory_area);
char *page_area_addr = (char *)bitmap + bitmap_size; char *page_area_addr = (char *)bitmap + bitmap_size;
bitmap = mmap(bitmap, bitmap_size); bitmap = mmap(bitmap, bitmap_size);
ltoa((long)bitmap, buf, 16);
memset(bitmap, 0, 12);
memset(bitmap, 0, bitmap_size); memset(bitmap, 0, bitmap_size);
memory_start = page_align(kernel_end + bitmap_size + page_area_size); memory_start = page_align(kaddr(kernel_end) + bitmap_size + page_area_size);
page_area_addr = mmap(page_area_addr, page_area_size); page_area_addr = mmap(page_area_addr, page_area_size);
page_start = (struct memory_area *) page_area_addr; page_start = (struct memory_area *) page_area_addr;

18
src/memory/virtalloc.c
View file

@ -26,7 +26,7 @@ static struct addr_node *alloc_node(void) {
} else { } else {
struct addr_node *node = &nodes[bss_nodes]; struct addr_node *node = &nodes[bss_nodes];
bss_nodes += 1; bss_nodes += 1;
node->is_bss = false; node->is_bss = true;
return node; return node;
} }
return NULL; return NULL;
@ -39,8 +39,8 @@ static void free_node(struct addr_node *node) {
void virtaddr_init(void) { void virtaddr_init(void) {
struct addr_node init = { struct addr_node init = {
.start = 0, .start = 0x400000, // third page table
.end = UINT64_MAX, .end = 0x1000000000000, // 48bit memory address max
.next = NULL, .next = NULL,
.prev = NULL, .prev = NULL,
.is_alloc = false, .is_alloc = false,
@ -53,6 +53,10 @@ void virtaddr_init(void) {
void *virtaddr_alloc(int n_pages) { void *virtaddr_alloc(int n_pages) {
if (n_pages < 1)
return NULL;
long n_length = n_pages * PAGE_SIZE; long n_length = n_pages * PAGE_SIZE;
struct addr_node *node = start_node; struct addr_node *node = start_node;
@ -64,17 +68,19 @@ void *virtaddr_alloc(int n_pages) {
long length = node->end - node->start; long length = node->end - node->start;
if (length >= n_length) { if (length >= n_length) {
struct addr_node *new = alloc_node(); struct addr_node *new = alloc_node();
if (node == NULL) if (node == NULL) {
return NULL; return NULL;
new->next = node; }
node->prev = new;
if (node->prev != NULL) { if (node->prev != NULL) {
node->prev->next = new; node->prev->next = new;
} }
new->next = node;
node->prev = new;
new->start = node->start; new->start = node->start;
new->end = new->start + n_length; new->end = new->start + n_length;
node->start = new->end; node->start = new->end;
new->is_alloc = true; new->is_alloc = true;
new->next = node;
return (void *) new->start; return (void *) new->start;
} }
} }