void physmem_init(void *boot_info)
{
multiboot_info_t *mb_info = (multiboot_info_t*)boot_info;
uint64_t *mem_ptr = (uint64_t*)(uint64_t)mb_info->memory_map_addr;
uint64_t Itr = 0, last_address = 0;
/* Setup Memory Stuff */
highest_page = 0;
memory_size = mb_info->memory_high;
memory_size += mb_info->memory_low;
total_blocks = (memory_size * 1024) / PAGE_SIZE;
used_blocks = total_blocks;
bitmap_size = total_blocks / PMM_BLOCKS_PER_BYTE;
_mem_bitmap = (uint64_t*)stalloc(bitmap_size);
physmem_lock = (spinlock_t*)stalloc(sizeof(spinlock_t));
spinlock_reset(physmem_lock);
/* Set all memory as used, and use memory map to set free */
memoryset(_mem_bitmap, 0xF, bitmap_size);
/* Physical Page Bitmap */
kprintf("Memory size: %u Kb\n", (uint32_t)memory_size);
/* Go through regions */
for(Itr = (uint64_t)mem_ptr;
Itr < ((uint64_t)mem_ptr + mb_info->memory_map_length);
)
{
/* Get next member */
mem_region_t *mem_region = (mem_region_t*)Itr;
/* Output */
//kprintf("Memory Region: Address 0x%xL, length 0x%xL, Type %u\n",
// mem_region->base_address, mem_region->length, mem_region->Type);
/* Is it free? */
if(mem_region->type == MEMTYPE_FREE)
physmem_freeregion(mem_region->base_address,
mem_region->length);
/* Advance by one structure */
Itr += sizeof(mem_region_t);
}
/* Mark all memory up to the static allocation point as used */
last_address = (physaddr_t)stalloc(1);
stalloc_disable();
for(Itr = physmem_allocblock(); Itr < last_address;)
Itr = physmem_allocblock();
/* Debug*/
kprintf("New memory allocation starts at 0x%xl\n", Itr);
}
void* syscall_memlimit(void* new_end){
uint32_t phys_page;
interrupt_status_t intr_status;
intr_status = _interrupt_disable();
spinlock_acquire(&process_table_slock);
process_control_block_t *curr_proc = process_get_current_process_entry();
// checks if the new_end is NULL
if (new_end == NULL){
spinlock_release(&process_table_slock);
_interrupt_set_state(intr_status);
return (void*)curr_proc->heap_end;
}
// checks if we are trying to shrink the memory, if so we error
// and return NULL
if ((uint32_t)new_end < curr_proc->heap_end){
spinlock_release(&process_table_slock);
_interrupt_set_state(intr_status);
return NULL;
}
// loop where we alloc the physical and the virtual memoery, we also check
// if we have enough physical memory.
for (uint32_t i = (curr_proc->heap_end / PAGE_SIZE +1);
i <= ((uint32_t)new_end / PAGE_SIZE);i++){
// we allocate some physical memory.
phys_page = physmem_allocblock();
//check if we got enough physical memory, if we do not we error
if (phys_page == 0){
spinlock_release(&process_table_slock);
_interrupt_set_state(intr_status);
return NULL;
}
// maps the virtual memory
vm_map(thread_get_current_thread_entry()->pagetable,
phys_page, i * PAGE_SIZE, 1);
}
// if nothing fails we at last set heap_end to new_end
curr_proc->heap_end = (uint32_t)new_end;
spinlock_release(&process_table_slock);
_interrupt_set_state(intr_status);
return new_end;
}
/* Return non-zero on error. */
int setup_new_process(TID_t thread,
const char *executable, const char **argv_src,
virtaddr_t *entry_point, virtaddr_t *stack_top)
{
pagetable_t *pagetable;
elf_info_t elf;
openfile_t file;
uintptr_t phys_page;
int i, res;
thread_table_t *thread_entry = thread_get_thread_entry(thread);
int argc = 1;
virtaddr_t argv_begin;
virtaddr_t argv_dst;
int argv_elem_size;
virtaddr_t argv_elem_dst;
file = vfs_open((char *)executable);
/* Make sure the file existed and was a valid ELF file */
if (file < 0) {
return -1;
}
res = elf_parse_header(&elf, file);
if (res < 0) {
return -1;
}
/* Trivial and naive sanity check for entry point: */
if (elf.entry_point < PAGE_SIZE) {
return -1;
}
*entry_point = elf.entry_point;
pagetable = vm_create_pagetable(thread);
thread_entry->pagetable = pagetable;
/* Allocate and map stack */
for(i = 0; i < CONFIG_USERLAND_STACK_SIZE; i++) {
phys_page = physmem_allocblock();
KERNEL_ASSERT(phys_page != 0);
/* Zero the page */
memoryset((void*)ADDR_PHYS_TO_KERNEL(phys_page), 0, PAGE_SIZE);
vm_map(pagetable, phys_page,
(USERLAND_STACK_TOP & PAGE_SIZE_MASK) - i*PAGE_SIZE, 1);
}
/* Allocate and map pages for the segments. We assume that
segments begin at page boundary. (The linker script in tests
directory creates this kind of segments) */
for(i = 0; i < (int)elf.ro_pages; i++) {
int left_to_read = elf.ro_size - i*PAGE_SIZE;
phys_page = physmem_allocblock();
KERNEL_ASSERT(phys_page != 0);
/* Zero the page */
memoryset((void*)ADDR_PHYS_TO_KERNEL(phys_page), 0, PAGE_SIZE);
/* Fill the page from ro segment */
if (left_to_read > 0) {
KERNEL_ASSERT(vfs_seek(file, elf.ro_location + i*PAGE_SIZE) == VFS_OK);
KERNEL_ASSERT(vfs_read(file, (void*)ADDR_PHYS_TO_KERNEL(phys_page),
MIN(PAGE_SIZE, left_to_read))
== (int) MIN(PAGE_SIZE, left_to_read));
}
vm_map(pagetable, phys_page,
elf.ro_vaddr + i*PAGE_SIZE, 0);
}
for(i = 0; i < (int)elf.rw_pages; i++) {
int left_to_read = elf.rw_size - i*PAGE_SIZE;
phys_page = physmem_allocblock();
KERNEL_ASSERT(phys_page != 0);
/* Zero the page */
memoryset((void*)ADDR_PHYS_TO_KERNEL(phys_page), 0, PAGE_SIZE);
/* Fill the page from rw segment */
if (left_to_read > 0) {
KERNEL_ASSERT(vfs_seek(file, elf.rw_location + i*PAGE_SIZE) == VFS_OK);
KERNEL_ASSERT(vfs_read(file, (void*)ADDR_PHYS_TO_KERNEL(phys_page),
MIN(PAGE_SIZE, left_to_read))
== (int) MIN(PAGE_SIZE, left_to_read));
}
vm_map(pagetable, phys_page,
elf.rw_vaddr + i*PAGE_SIZE, 1);
}
/* Set up argc and argv on the stack. */
/* Start by preparing ancillary information for the new process argv. */
if (argv_src != NULL)
for (i = 0; argv_src[i] != NULL; i++) {
argc++;
}
argv_begin = USERLAND_STACK_TOP - (argc * sizeof(virtaddr_t));
argv_dst = argv_begin;
/* Prepare for copying executable. */
argv_elem_size = strlen(executable) + 1;
argv_elem_dst = argv_dst - wordpad(argv_elem_size);
/* Copy executable to argv[0] location. */
vm_memwrite(pagetable,
argv_elem_size,
argv_elem_dst,
executable);
/* Set argv[i] */
vm_memwrite(pagetable,
sizeof(virtaddr_t),
argv_dst,
&argv_elem_dst);
/* Move argv_dst to &argv[1]. */
argv_dst += sizeof(virtaddr_t);
if (argv_src != NULL) {
for (i = 0; argv_src[i] != NULL; i++) {
/* Compute the size of argv[i+1] */
argv_elem_size = strlen(argv_src[i]) + 1;
argv_elem_dst -= wordpad(argv_elem_size);
/* Write the 'i+1'th element of argv */
vm_memwrite(pagetable,
argv_elem_size,
argv_elem_dst,
argv_src[i]);
/* Write argv[i+1] */
vm_memwrite(pagetable,
sizeof(virtaddr_t),
argv_dst,
&argv_elem_dst);
/* Move argv_dst to next element of argv. */
argv_dst += sizeof(virtaddr_t);
}
}
/* Write argc to the stack. */
vm_memwrite(pagetable,
sizeof(int),
argv_elem_dst - sizeof(int),
&argc);
/* Write argv to the stack. */
vm_memwrite(pagetable,
sizeof(virtaddr_t),
argv_elem_dst - sizeof(int) - sizeof(virtaddr_t),
&argv_begin);
/* Stack pointer points at argv. */
*stack_top = argv_elem_dst - sizeof(int) - sizeof(virtaddr_t);
return 0;
}
