better mboot and kalloc

This commit is contained in:
Freya Murphy 2024-01-31 12:49:06 -05:00
parent f790341368
commit 50fee8495e
Signed by: freya
GPG key ID: 744AB800E383AE52
10 changed files with 512 additions and 137 deletions

View file

@ -2,19 +2,7 @@
#include <stddef.h> #include <stddef.h>
#include <stdint.h> #include <stdint.h>
#include <shim.h>
struct memory_segment {
uint64_t addr;
uint64_t len;
uint32_t type;
uint32_t reserved;
} __attribute__((packed));
struct memory_map {
uint32_t size;
uint32_t version;
struct memory_segment entries[];
} __attribute__((packed));
/** /**
* Initalize system memory allocator * Initalize system memory allocator
@ -61,10 +49,23 @@ extern void *alloc_page(void);
extern void *alloc_pages(int count); extern void *alloc_pages(int count);
/** /**
* Frees a single page in memory * Frees a signle page in memory.
* Must be a page aligned allocated vitural pointer.
* Freeing in the middle of a block is allowed.
* @param page - the pointer to the page * @param page - the pointer to the page
*/ */
extern void free_page(void *page); extern void free_page(void *page);
// TODO: implement free_page
/**
* Frees block of pages in memory.
* Must be a page aligned allocated vitural pointer.
* Freeing int he middle of a block is allowed,
* free_pages will from *page to end of block allocated.
* @param page - the pointer to the page
*/
extern void free_pages(void *page);
// TODO: implement freeing in middle of block
/** /**
* Allocates at least len bytes of memory starting at * Allocates at least len bytes of memory starting at
@ -89,7 +90,7 @@ extern void unmap(void *addr);
* @param size - the amount of bytes to allocate * @param size - the amount of bytes to allocate
* @retruns the address allocated or NULL on failure * @retruns the address allocated or NULL on failure
*/ */
extern void *malloc(size_t size); extern void *kalloc(size_t size);
/** /**
* Reallocates a given allocated ptr to a new size of bytes in memory. * Reallocates a given allocated ptr to a new size of bytes in memory.
@ -98,10 +99,10 @@ extern void *malloc(size_t size);
* @param size - the amount of bytes to set the pointer to * @param size - the amount of bytes to set the pointer to
* @returns the address allocated or NULL on failure * @returns the address allocated or NULL on failure
*/ */
extern void *realloc(void *ptr, size_t size); extern void *krealloc(void *ptr, size_t size);
/** /**
* Frees a allocated pointer in memory * Frees a allocated pointer in memory
* @param ptr - the pointer to free * @param ptr - the pointer to free
*/ */
extern void free(void *ptr); extern void kfree(void *ptr);

View file

@ -4,8 +4,20 @@
#define CMDLINE_MAX 32 #define CMDLINE_MAX 32
struct memory_segment {
uint64_t addr;
uint64_t len;
uint32_t type;
};
struct memory_map {
uint32_t entry_count;
uint32_t entry_length;
struct memory_segment *entries;
};
struct boot_info { struct boot_info {
struct memory_map *map; struct memory_map map;
void *symbol_table; void *symbol_table;
void *acpi_table; void *acpi_table;
char cmdline[CMDLINE_MAX]; char cmdline[CMDLINE_MAX];

View file

@ -5,6 +5,7 @@
#include <stddef.h> #include <stddef.h>
#include "bindings.h" #include "bindings.h"
#include "memory.h"
#include "serial.h" #include "serial.h"
/* global state, idk a better way rn */ /* global state, idk a better way rn */
@ -51,7 +52,7 @@ struct xsdp {
// ACPI 1.0 // ACPI 1.0
struct rsdt { struct rsdt {
struct acpi_header h; struct acpi_header h;
uint64_t sdt_pointers[]; uint32_t sdt_pointers[];
}; };
// eXtended system descriptor table // eXtended system descriptor table
@ -140,6 +141,11 @@ struct fadt {
}; };
struct acpi_state { struct acpi_state {
union {
struct xsdt *xsdt;
struct rsdt *rsdt;
} dst;
uint8_t version;
struct fadt fadt; struct fadt fadt;
uint16_t SLP_TYPa; uint16_t SLP_TYPa;
uint16_t SLP_TYPb; uint16_t SLP_TYPb;
@ -196,10 +202,15 @@ static int read_s5_addr(struct acpi_state *state) {
} }
static void *acpi_find_table_rsdt(struct rsdt *rsdt, const char *identifier, int ident_len) { static void *acpi_find_table_rsdt(struct rsdt *rsdt, const char *identifier, int ident_len) {
int entries = (rsdt->h.length - sizeof(rsdt->h)) / 8; int entries = (rsdt->h.length - sizeof(rsdt->h)) / 4;
for (int i = 0; i < entries; i++) { for (int i = 0; i < entries; i++) {
struct acpi_header *h = (struct acpi_header *) (uintptr_t) rsdt->sdt_pointers[i]; struct acpi_header *h = (struct acpi_header *) (uintptr_t) rsdt->sdt_pointers[i];
char buf[6];
memcpy(buf, h->signature, 4);
buf[4] = '\n';
buf[5] = '\0';
serial_out_str(buf);
if (!strncmp(h->signature, identifier, ident_len)) if (!strncmp(h->signature, identifier, ident_len))
return (void *)h; return (void *)h;
} }
@ -222,6 +233,11 @@ static void *acpi_find_table_xsdt(struct xsdt *xsdt, const char *identifier, int
} }
int acpi_init_rsdt(struct rsdt *rsdt) { int acpi_init_rsdt(struct rsdt *rsdt) {
rsdt = mmap(rsdt, sizeof(struct rsdt));
state.dst.rsdt = rsdt;
state.version = 0;
if (!checksum((uint8_t *) &rsdt->h, rsdt->h.length)) if (!checksum((uint8_t *) &rsdt->h, rsdt->h.length))
return -1; return -1;
@ -238,6 +254,11 @@ int acpi_init_rsdt(struct rsdt *rsdt) {
} }
int acpi_init_xsdt(struct xsdt *xsdt) { int acpi_init_xsdt(struct xsdt *xsdt) {
xsdt = mmap(xsdt, sizeof(struct xsdt));
state.dst.xsdt = xsdt;
state.version = 2;
if (!checksum((uint8_t *) &xsdt->h, xsdt->h.length)) if (!checksum((uint8_t *) &xsdt->h, xsdt->h.length))
return -1; return -1;
@ -256,7 +277,7 @@ int acpi_init_xsdt(struct xsdt *xsdt) {
int acpi_init(void *rootsdp) { int acpi_init(void *rootsdp) {
struct rsdp *rsdp = (struct rsdp *) rootsdp; struct rsdp *rsdp = (struct rsdp *) rootsdp;
if (!checksum((uint8_t *)rsdp, sizeof(struct xsdp))) if (!checksum((uint8_t *)rsdp, sizeof(struct rsdp)))
return -1; return -1;
int res; int res;

View file

@ -1,5 +1,9 @@
ENTRY(start) ENTRY(start)
PHDRS {
loadable PT_LOAD FLAGS(7) ;
}
SECTIONS { SECTIONS {
. = 1M; . = 1M;
@ -25,5 +29,10 @@ SECTIONS {
*(.bss) *(.bss)
} }
.symtab : {
symtab = .;
*(.symtab)
} :loadable
kernel_end = .; kernel_end = .;
} }

View file

@ -1,71 +1,227 @@
#include "mboot.h" #include "mboot.h"
#include "serial.h"
#include "shim.h" #include "shim.h"
#include <lib.h> #include <lib.h>
#include <stdint.h>
extern char symtab;
#define kaddr(addr) ((uintptr_t)(&addr))
typedef unsigned char mboot_uint8_t;
typedef unsigned short mboot_uint16_t;
typedef unsigned int mboot_uint32_t;
typedef unsigned long long mboot_uint64_t;
struct mboot_info {
mboot_uint32_t total_size;
mboot_uint32_t reserved;
char tags[];
};
struct mboot_tag {
mboot_uint32_t type;
mboot_uint32_t size;
char data[];
};
enum mboot_tag_type { enum mboot_tag_type {
MBOOT_CMDLINE = 0, MBOOT_CMDLINE = 0,
MBOOT_MEMORYMAP = 6, MBOOT_MEMORYMAP = 6,
MBOOT_SYMBOLS = 9, MBOOT_SYMBOLS = 9,
MBOOT_XSDP = 14 MBOOT_RSDP = 14,
MBOOT_XSDP = 15,
}; };
static void read_cmdline(struct boot_info *shim_info, char *data, uint8_t len) { struct mboot_elf_header_layout {
if (len >= CMDLINE_MAX) mboot_uint32_t type;
len = CMDLINE_MAX; // truncate :( mboot_uint32_t size;
memcpy(shim_info->cmdline, data, len); mboot_uint32_t num;
shim_info->cmdline[len] = '\0'; mboot_uint32_t entsize;
mboot_uint32_t shndx;
char elf_section_headers[];
};
struct mboot_elf_section_header {
mboot_uint32_t sh_name;
mboot_uint32_t sh_type;
mboot_uint64_t sh_flags;
mboot_uint64_t sh_addr;
mboot_uint64_t sh_offset;
mboot_uint64_t sh_size;
mboot_uint32_t sh_link;
mboot_uint32_t sh_info;
mboot_uint64_t sh_addralign;
mboot_uint64_t sh_entsize;
};
struct mboot_memory_segment {
mboot_uint64_t addr;
mboot_uint64_t len;
mboot_uint32_t type;
mboot_uint32_t reserved;
};
struct mboot_memory_map {
mboot_uint32_t tag;
mboot_uint32_t size;
mboot_uint32_t entry_size;
mboot_uint32_t entry_version;
struct memory_segment entries[];
};
struct mboot_rsdp {
mboot_uint32_t tag;
mboot_uint32_t size;
mboot_uint8_t rsdp[];
};
struct mboot_xsdp {
mboot_uint32_t tag;
mboot_uint32_t size;
mboot_uint8_t xsdp[];
};
struct mboot_cmdline {
mboot_uint32_t tag;
mboot_uint32_t size;
char cmdline[];
};
static void read_symbols(
struct boot_info *shim_info,
struct mboot_elf_header_layout *layout
) {
shim_info->symbol_table = layout->elf_section_headers;
// struct mboot_elf_section_header *section =
// (struct mboot_elf_section_header *) (layout->elf_section_headers);
//
// for (mboot_uint32_t i = 0; i < layout->num; i++) {
// char buf[20];
//
// ultoa(i, buf, 10);
// serial_out_str("[");
// serial_out_str(buf);
// serial_out_str("]\t");
//
// serial_out_str((char *)(kaddr(symtab) + section->sh_name));
// serial_out('\t');
//
// ultoa(section->sh_type, buf, 16);
// serial_out_str("type: 0x");
// serial_out_str(buf);
// serial_out('\t');
//
// ultoa(section->sh_addr, buf, 16);
// serial_out_str("addr: 0x");
// serial_out_str(buf);
// serial_out('\t');
//
// ultoa(section->sh_offset, buf, 16);
// serial_out_str("offset: 0x");
// serial_out_str(buf);
// serial_out('\n');
//
// section++;
// }
} }
static void read_memorymap(struct boot_info *shim_info, uint64_t size, uint32_t *data) { static void read_cmdline(
shim_info->map = (struct memory_map *) data; struct boot_info *shim_info,
shim_info->map->size = size; struct mboot_cmdline *cmdline
) {
mboot_uint32_t size = cmdline->size - 8;
if (size >= CMDLINE_MAX)
size = CMDLINE_MAX; // truncate :(
memcpy(shim_info->cmdline, cmdline->cmdline, size);
shim_info->cmdline[size] = '\0';
} }
static void read_xsdp(struct boot_info *shim_info, char *data) { static void read_memorymap(
shim_info->acpi_table = (void *) data; struct boot_info *shim_info,
struct mboot_memory_map *map
) {
int size = map->size - sizeof(mboot_uint32_t) * 4;
int count = size / map->entry_size;
shim_info->map.entry_count = count;
shim_info->map.entry_length = map->entry_size;
shim_info->map.entries = map->entries;
} }
static uint32_t *read_tag(uint32_t *data, struct boot_info *shim_info) { static void read_rsdp(
struct boot_info *shim_info,
struct mboot_rsdp *rsdp
) {
if (shim_info->acpi_table != NULL)
return; // xsdp is newer and has been loaded
shim_info->acpi_table = rsdp->rsdp;
}
uint16_t type = *((uint16_t *)data); static void read_xsdp(
uint32_t size = data[1]; struct boot_info *shim_info,
struct mboot_xsdp *xsdp
) {
shim_info->acpi_table = xsdp->xsdp;
}
uint8_t data_len = size - 2 * sizeof(uint32_t); void mboot_load_info(
const void *mboot_data_ptr,
struct boot_info *shim_info
) {
switch (type) { memset(shim_info, 0, sizeof(struct boot_info));
struct mboot_info *mboot_info = (struct mboot_info *) mboot_data_ptr;
const char *mboot_end = ((char *) mboot_info) + mboot_info->total_size;
char *tag_ptr = mboot_info->tags;
while (tag_ptr < mboot_end) {
struct mboot_tag *tag = (struct mboot_tag *) tag_ptr;
switch (tag->type) {
case MBOOT_CMDLINE: case MBOOT_CMDLINE:
read_cmdline(shim_info, (char *)(data + 2), data_len); read_cmdline(
shim_info,
(struct mboot_cmdline *) tag
);
break; break;
case MBOOT_MEMORYMAP: case MBOOT_MEMORYMAP:
read_memorymap(shim_info, size, data + 2); read_memorymap(
shim_info,
(struct mboot_memory_map *) tag
);
break; break;
case MBOOT_SYMBOLS: case MBOOT_SYMBOLS:
shim_info->symbol_table = (void *) (data + 2); read_symbols(
shim_info,
(struct mboot_elf_header_layout *) tag
);
break;
case MBOOT_RSDP:
read_rsdp(
shim_info,
(struct mboot_rsdp *) tag
);
break; break;
case MBOOT_XSDP: case MBOOT_XSDP:
read_xsdp(shim_info, (char *) (data + 2)); read_xsdp(
shim_info,
(struct mboot_xsdp *) tag
);
break; break;
default: default:
break; break;
} }
if(size % 8 != 0) { int size = tag->size;
if (size % 8 != 0) {
size += 8 - (size % 8); size += 8 - (size % 8);
} }
return data + size / sizeof(uint32_t); tag_ptr += size;
}
void mboot_load_info(
const void *mboot_info,
struct boot_info *shim_info
) {
uint32_t* data = (uint32_t*) mboot_info;
uint32_t total_size = *data++;
data++; //reserved
while((uint8_t*) data < (uint8_t*) mboot_info + total_size) {
data = read_tag(data, shim_info);
} }
} }

View file

@ -1,3 +1,4 @@
#include <panic.h>
#include <cpuid.h> #include <cpuid.h>
#include <stdint.h> #include <stdint.h>
#include <lib.h> #include <lib.h>
@ -568,6 +569,11 @@ void *alloc_pages(int count) {
} }
void free_page(void *virt) { void free_page(void *virt) {
(void) virt;
panic("free_page is not yet implemented");
}
void free_pages(void *virt) {
long pages = virtaddr_free(virt); long pages = virtaddr_free(virt);
if (pages < 1) if (pages < 1)
return; return;

View file

@ -1,36 +1,12 @@
#include "acpi.h" #include <acpi.h>
#include <memory.h> #include <memory.h>
#include <lib.h> #include <lib.h>
#include <serial.h> #include <serial.h>
#include <fb.h> #include <fb.h>
#include <shim.h> #include <shim.h>
void print_memory() {
size_t WIDTH = 64;
for(size_t i = 0;; i += WIDTH) {
char buf[20];
ultoa(i, buf, 16);
serial_out_str("0x");
for(size_t k = 0; k < 6 - strlen(buf); k++) {
serial_out('0');
}
serial_out_str(buf);
serial_out_str(": ");
for(size_t j = 0; j < WIDTH; j++) {
char x = *(char *)(i + j);
if(x < 0x20 || x >= 0x7f) {
serial_out('.');
} else {
serial_out(x);
}
}
serial_out('\n');
}
}
void kmain(struct boot_info *info) { void kmain(struct boot_info *info) {
memory_init(info->map); memory_init(&info->map);
//acpi_init(info->acpi_table); //acpi_init(info->acpi_table);
//fb_init(1024, 768); //fb_init(1024, 768);

214
src/memory/memory.c Normal file
View file

@ -0,0 +1,214 @@
#include <memory.h>
#include <stdint.h>
#include <lib.h>
#ifdef MEMORY_PANIC
#include <panic.h>
#endif
#define MAGIC 0xBEEFCAFE
struct page_header {
struct page_header *next;
struct page_header *prev;
size_t node_number; // all headers on the same page alloc have the same node number (so they can be merged)
size_t free; // free space after the node (if its the last node in the alloc block)
size_t used; // how much space this allocation is using
uint64_t magic;
};
static const size_t header_len = sizeof(struct page_header);
struct page_header *start_header = NULL;
struct page_header *end_header = NULL;
struct page_header* get_header(void *ptr) {
struct page_header *header =
(struct page_header *) ((uintptr_t) ptr - header_len);
// PERF: do we want to make sure this pointer is paged
// before reading it???
if (header->magic != MAGIC) {
return NULL; // invalid pointer
}
return header;
}
void *kalloc_new(size_t size) {
size_t pages = ((size + header_len) / PAGE_SIZE) + 1;
void *addr = alloc_pages(pages);
void *mem = (char *)addr + header_len;
size_t total = pages * PAGE_SIZE;
size_t free = total - (size + header_len);
if (addr == NULL) {
return NULL;
}
size_t node;
if (end_header != NULL) {
node = end_header->node_number + 1;
} else {
node = 0;
}
struct page_header *header = addr;
header->magic = MAGIC;
header->used = size;
header->free = free;
header->prev = end_header;
header->next = NULL;
header->node_number = node;
if (end_header == NULL) {
start_header = header;
} else {
end_header->next = header;
}
end_header = header;
return mem;
}
void *kalloc_block(size_t size, struct page_header *block) {
struct page_header *header =
(struct page_header *) ((char *) block + block->used + header_len);
size_t free = block->free - (size + header_len);
block->free = 0;
header->magic = MAGIC;
header->used = size;
header->free = free;
header->prev = block;
header->next = block->next;
block->next = header;
header->node_number = block->node_number;
void *mem = (char *) header + header_len;
return mem;
}
void *kalloc(size_t size) {
struct page_header *header = start_header;
for (; header != NULL; header = header->next) {
size_t free = header->free;
if (size <= (free - header_len)) { // we must be able to fit data + header
break;
}
}
if (header != NULL) {
return kalloc_block(size, header);
} else {
return kalloc_new(size);
}
}
void *krealloc(void *src, size_t dst_len) {
struct page_header *header;
size_t src_len;
void *dst;
// realloc of 0 means free pointer
if (dst_len == 0) {
kfree(src);
return NULL;
}
// NULL src means allocate ptr
if (src == NULL) {
dst = kalloc(dst_len);
return dst;
}
header = get_header(src);
if (header == NULL) {
#ifdef MEMORY_PANIC
panic("attempted to realloc on a invalid ptr");
#else
return NULL; // invalid pointer passed
#endif
}
src_len = header->used;
if (src_len == 0) {
#ifdef MEMORY_PANIC
panic("attempted to realloc on an empty ptr");
#else
return NULL; // likely double free :(
#endif
}
dst = kalloc(dst_len);
if (dst == NULL) {
return NULL; // allocation failed
}
memcpy(dst, src, src_len);
return dst;
}
void kfree(void *ptr) {
struct page_header *header;
if (ptr == NULL) {
return;
}
header = get_header(ptr);
if (header == NULL || header->used == 0) {
#ifdef MEMORY_PANIC
panic("attempted to kfree invalid pointer");
#else
return;
#endif
}
header->free += header->used;
header->used = 0;
struct page_header *neighbor;
// merge left
for (neighbor = header->prev; neighbor != NULL; neighbor = neighbor->prev) {
if (neighbor->node_number != header->node_number)
break;
if (neighbor->used && header->used)
break;
neighbor->free += header->free + header_len;
neighbor->next = header->next;
header = neighbor;
}
// merge right
for (neighbor = header->next; neighbor != NULL; neighbor = neighbor->next) {
if (neighbor->node_number != header->node_number)
break;
if (neighbor->used)
break;
header->free += neighbor->free + header_len;
header->next = neighbor->next;
}
if (
(header->next == NULL || header->next->node_number != header->node_number) &&
(header->prev == NULL || header->prev->node_number != header->node_number) &&
header->used == 0
) {
if (header->next)
header->next->prev = header->prev;
if (header->prev)
header->prev->next = header->next;
free_pages(header);
}
}

View file

@ -163,13 +163,11 @@ void memory_init(struct memory_map *map) {
page_free_start = 0; page_free_start = 0;
page_start = NULL; page_start = NULL;
uintptr_t end = (uintptr_t) map;
end += map->size;
struct memory_segment *segment = &map->entries[0];
segment_count = 0; segment_count = 0;
for(; (uintptr_t) segment < end; segment++) { for(uint32_t i = 0; i < map->entry_count; i++) {
struct memory_segment *segment = &map->entries[i];
if (segment_invalid(segment)) if (segment_invalid(segment))
continue; continue;
@ -196,9 +194,10 @@ void memory_init(struct memory_map *map) {
page_start = (struct memory_area *) page_area_addr; page_start = (struct memory_area *) page_area_addr;
struct memory_area *area = page_start; struct memory_area *area = page_start;
segment = &map->entries[0];
for(; (uintptr_t) segment < end; segment++) { for(uint32_t i = 0; i < map->entry_count; i++) {
struct memory_segment *segment = &map->entries[i];
if (segment_invalid(segment)) if (segment_invalid(segment))
continue; continue;
@ -229,24 +228,3 @@ uint64_t memory_used(void) {
return total_memory - free_memory; return total_memory - free_memory;
} }
// stubs
// simon do these ik you want to
// :3
void *malloc(size_t size) {
//TODO: implement
(void)size;
return NULL;
}
void *realloc(void *ptr, size_t size) {
//TODO: implement
(void)ptr;
(void)size;
return NULL;
}
void free(void *ptr) {
//TODO: implement
(void)ptr;
}

View file

@ -21,20 +21,23 @@ static struct addr_node nodes[BOOTSTRAP_BSS_NODES];
static struct addr_node *start_node; static struct addr_node *start_node;
static struct addr_node *alloc_node(void) { static struct addr_node *alloc_node(void) {
struct addr_node *node = NULL;
if (bss_nodes >= BOOTSTRAP_BSS_NODES) { if (bss_nodes >= BOOTSTRAP_BSS_NODES) {
//FIXME: alloc on heap node = kalloc(sizeof(struct addr_node));
if (node == NULL)
return NULL;
node->is_bss = false;
} else { } else {
struct addr_node *node = &nodes[bss_nodes]; node = &nodes[bss_nodes];
bss_nodes += 1; bss_nodes += 1;
node->is_bss = true; node->is_bss = true;
return node;
} }
return NULL; return node;
} }
static void free_node(struct addr_node *node) { static void free_node(struct addr_node *node) {
if (!node->is_bss) if (!node->is_bss)
free(node); kfree(node);
} }
void virtaddr_init(void) { void virtaddr_init(void) {
@ -53,7 +56,6 @@ void virtaddr_init(void) {
void *virtaddr_alloc(int n_pages) { void *virtaddr_alloc(int n_pages) {
if (n_pages < 1) if (n_pages < 1)
return NULL; return NULL;