void switch_to_user_mode()
{
alloc_page_dir(&(bar_p));
_ptcr3(bar_p.cr3);
alloc_user_stack(&(bar_p));
bar_p.rsp_p = (uint64_t)&(bar_p.k_stack[63]);
printf("\n Inside call %p\n",(uint64_t)video_vm);
tss.rsp0 = bar_p.rsp_p;
uint64_t tem = 0x28;
__asm volatile("mov %0,%%rax;"::"r"(tem));
__asm volatile("ltr %ax");
__asm volatile("\
push $0x23;\
push %0;\
pushf;\
push $0x1B;\
push %1"::"g"(&bar_p.u_stack[511]),"g"(&bar):"memory");
__asm volatile("\
iretq;\
");
}
static int try_load_elf(elf_prog_t *prog, long bailout)
{
int err, has_interp;
char i_filename[PATH_MAX]; /* so much easier */
elf_bin_t *bin=&prog->bin, *interp=&prog->interp;
if ( (err = open_elf(prog->filename, bin)) < 0 )
return err;
Elf32_Phdr phdr_bin_tmp[bin->hdr.e_phnum];
bin->phdr = phdr_bin_tmp; /* point to mmapped region later if any */
if (read_at(bin->fd, bin->hdr.e_phoff, bin->phdr,
sizeof(*bin->phdr)*bin->hdr.e_phnum) !=
(long)sizeof(*bin->phdr)*bin->hdr.e_phnum)
return -EIO;
if ( (err = find_interp_name(bin, i_filename, PATH_MAX)) < 0 )
return err;
has_interp = err;
interp->phdr = NULL;
interp->hdr.e_phnum = 0;
if ( has_interp && (err = open_elf(i_filename, interp)) < 0)
return err;
Elf32_Phdr phdr_interp_tmp[interp->hdr.e_phnum];
if ( has_interp )
{
interp->phdr = phdr_interp_tmp; /* point to mmapped region later */
if (read_at(interp->fd, interp->hdr.e_phoff, interp->phdr,
sizeof(*interp->phdr)*interp->hdr.e_phnum) !=
(long)sizeof(*interp->phdr)*interp->hdr.e_phnum)
return -EIO;
}
/* point of no return */
if (bailout)
return 0;
int stack_prot = get_stack_prot(bin);
err = alloc_user_stack(prog, stack_prot);
if ( mmap_binary(bin, 0) & PG_MASK )
raise(SIGKILL);
if ( has_interp && (mmap_binary(interp, 1) & PG_MASK) )
raise(SIGKILL);
/* set up stack */
bin->phdr = mapped_phdr(bin);
if ( has_interp )
interp->phdr = mapped_phdr(interp);
init_user_stack(prog, stack_prot);
if (err & PG_MASK)
raise(SIGKILL);
if (has_interp)
prog->entry = (void *)(interp->base + interp->hdr.e_entry);
else
prog->entry = (void *)(bin->base + bin->hdr.e_entry);
return 0;
}
//#define ENTRY 0X8048074
PCB* create_process(uint8_t *buf) {
struct ELFHeader *elf = (struct ELFHeader*) buf;
struct ProgramHeader *ph, *eph;
uint32_t va, eva, pa, len, sublen, tmpva, offset;
uint8_t *kst;
int ret;
PCB* pcb = create_kthread((void*)NULL);
ph = (struct ProgramHeader*)((char*)elf + elf->phoff);
eph = ph + elf->phnum;
assert(pcb != NULL);
printk("in create process pid=%d\n",pcb->pid);
for(; ph < eph; ph++) {
if(ph->type != PT_LOAD)
continue;
va = ph->vaddr; //in boot/main.c is paddr, it may be a bug
len = ph->memsz;
eva = va + len;
printk("segment start = %x\n",va);
printk("segment end = %x\n",eva);
//request new page here
//start= ph->vaddr, len=ph->memsz
//
printk("before alloc pages...va=%x\n",va);
ret = alloc_pages(pcb,va,len);
printk("after alloc pages\n");
assert(ret == 0); // must be successful
printk("after alloc pages and assertion\n");
//attention: virtual adrress to physical address
offset = ph->off;
for(; va < eva;) {
pa = pcb_va_to_pa(pcb,va);
printk("physical address = %x\n",pa);
kst = (uint8_t*)pa_to_va(pa); //virtual address
printk("virtual address = %x\n",kst);
tmpva = va; va = to_next_page(va) < eva ? to_next_page(va) : eva; //when va == ea this loop end
sublen = va - tmpva;
memcpy(kst, (char*)elf + offset,sublen);
offset += sublen;
}
}
printk("before alloc stack\n");
ret = alloc_user_stack(pcb);
assert(ret==0);
printk("after alloc user stack\n");
struct TrapFrame* tf = ((struct TrapFrame*)(pcb->tf));
tf->eip = elf->entry;//ENTRY;
//set user stack here
tf->cs = SELECTOR_USER(SEG_USER_CODE);
tf->ds = SELECTOR_USER(SEG_USER_DATA);
tf->irq = 1000;
tf->ss = SELECTOR_USER(SEG_USER_DATA);
tf->esp = USER_STACK_END;
//should I set tf->ebp?
return pcb;
}
