/*=======================================================
init_prot()
========================================================*/
PUBLIC void init_prot()
{
init_8259A();
//初始化异常 （中断门 没有陷阱门）
init_idt_desc( INT_VECTOR_DIVIDE, DA_386IGate, divide_error, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_DEBUG, DA_386IGate, single_step_exception, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_NMI, DA_386IGate, nmi, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_BREAKPOINT, DA_386IGate, breakpoint_exception, PRIVILEGE_USER);
init_idt_desc( INT_VECTOR_OVERFLOW, DA_386IGate , overflow, PRIVILEGE_USER);
init_idt_desc( INT_VECTOR_BOUNDS, DA_386IGate, bounds_check, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_INVAL_OP, DA_386IGate, inval_opcode, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_COPROC_NOT, DA_386IGate, copr_not_available, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_DOUBLE_FAULT, DA_386IGate, double_fault, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_COPROC_SEG, DA_386IGate, copr_seg_overrun, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_INVAL_TSS, DA_386IGate, inval_tss, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_SEG_NOT, DA_386IGate, segment_not_present, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_STACK_FAULT, DA_386IGate, stack_exception, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_PROTECTION, DA_386IGate, general_protection, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_PAGE_FAULT, DA_386IGate, page_fault, PRIVILEGE_KRNL);
init_idt_desc( INT_VECTOR_COPROC_ERR, DA_386IGate, copr_error, PRIVILEGE_KRNL);
/*初始化中断*/
init_idt_desc(INT_VECTOR_IRQ0 + 0, DA_386IGate , hint00 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 1, DA_386IGate , hint01 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 2, DA_386IGate , hint02 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 3, DA_386IGate , hint03 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 4, DA_386IGate , hint04 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 5, DA_386IGate , hint05 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 6, DA_386IGate , hint06 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 7, DA_386IGate , hint07 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 0, DA_386IGate , hint08 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 1, DA_386IGate , hint09 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 2, DA_386IGate , hint10 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 3, DA_386IGate , hint11 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 4, DA_386IGate , hint12 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 5, DA_386IGate , hint13 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 6, DA_386IGate , hint14 , PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 7, DA_386IGate , hint15 , PRIVILEGE_KRNL);
/* 填充 GDT 中的 TSS */
memset(&tss,0,sizeof(tss));
tss.ss0 = SELECTOR_KERNEL_DS;
init_descriptor(&gdt[INDEX_TSS],
vir2phys(seg2phys(SELECTOR_KERNEL_DS),&tss),
sizeof(tss) - 1, DA_386TSS);
tss.iobase = sizeof(tss); /*没有I/O许可位图*/
/*填充 GDT 中进程的 LDT的描述符 */
init_descriptor(&gdt[INDEX_LDT_FIRST],
vir2phys(seg2phys(SELECTOR_KERNEL_DS),proc_table[0].ldts),
LDT_SIZE * sizeof(DESCRIPTOR) - 1, DA_LDT);
}
phys_bytes pg_load()
{
phys_bytes phpagedir = vir2phys(pagedir);
refresh_tlb();
write_ttbr0(phpagedir);
return phpagedir;
}
PUBLIC void arch_get_aout_headers(const int i, struct exec *h)
{
/* The bootstrap loader created an array of the a.out headers at
* absolute address 'aout'. Get one element to h.
*/
phys_copy(aout + i * A_MINHDR, vir2phys(h), (phys_bytes) A_MINHDR);
}
PRIVATE void cons_setc(const int pos, const int c)
{
char ch;
ch= c;
phys_copy(vir2phys((vir_bytes)&ch), COLOR_BASE+(20*80+pos)*2, 1);
}
PUBLIC int arch_set_params(char *params, int size)
{
if(size > params_size)
return E2BIG;
phys_copy(vir2phys(params), seg2phys(mon_ds) + params_offset, size);
return OK;
}
PUBLIC int arch_get_params(char *params, int maxsize)
{
phys_copy(seg2phys(mon_ds) + params_offset, vir2phys(params),
MIN(maxsize, params_size));
params[maxsize-1] = '\0';
return OK;
}
static u32_t phys_get32(phys_bytes addr)
{
const u32_t v;
int r;
if(!vm_running) {
phys_copy(addr, vir2phys(&v), sizeof(v));
return v;
}
if((r=lin_lin_copy(NULL, addr,
proc_addr(SYSTEM), vir2phys(&v), sizeof(v))) != OK) {
panic("lin_lin_copy for phys_get32 failed: %d", r);
}
return v;
}
/*
** Name: void dp_pio16_user2nic(dpeth_t *dep, int pageno, int pktsize)
** Function: Copies a packet from user area to board (Prog. I/O, 16bits).
*/
static void dp_pio16_user2nic(dpeth_t *dep, int pageno, int pktsize)
{
u8_t two_bytes[2];
phys_bytes phys_user, phys_2bytes = vir2phys(two_bytes);
vir_bytes ecount = (pktsize + 1) & NOT(0x0001);
int bytes, ix = 0, odd_byte = 0;
iovec_dat_t *iovp = &dep->de_write_iovec;
outb_reg0(dep, DP_ISR, ISR_RDC);
dp_read_setup(dep, ecount, pageno * DP_PAGESIZE);
do {
bytes = iovp->iod_iovec[ix].iov_size;
if (bytes > pktsize) bytes = pktsize;
phys_user = numap(iovp->iod_proc_nr, iovp->iod_iovec[ix].iov_addr, bytes);
if (!phys_user) panic(UmapErrMsg);
if (odd_byte) {
phys_copy(phys_user, phys_2bytes + 1, (phys_bytes) 1);
out_word(dep->de_data_port, *(u16_t *)two_bytes);
pktsize--;
bytes--;
phys_user++;
odd_byte = 0;
if (!bytes) continue;
}
ecount = bytes & NOT(0x0001);
if (ecount != 0) {
phys_outsw(dep->de_data_port, phys_user, ecount);
pktsize -= ecount;
bytes -= ecount;
phys_user += ecount;
}
if (bytes) {
phys_copy(phys_user, phys_2bytes, (phys_bytes) 1);
pktsize--;
bytes--;
phys_user++;
odd_byte = 1;
}
if (++ix >= IOVEC_NR) { /* Next buffer of I/O vector */
dp_next_iovec(iovp);
ix = 0;
}
} while (bytes > 0);
if (odd_byte) out_word(dep->de_data_port, *(u16_t *) two_bytes);
for (ix = 0; ix < 100; ix++) {
if (inb_reg0(dep, DP_ISR) & ISR_RDC) break;
}
if (ix == 100) {
panic(RdmaErrMsg);
}
return;
}
/*
** Name: void dp_pio16_nic2user(dpeth_t *dep, int pageno, int pktsize)
** Function: Copies a packet from board to user area (Prog. I/O, 16bits).
*/
static void dp_pio16_nic2user(dpeth_t * dep, int nic_addr, int count)
{
phys_bytes phys_user;
vir_bytes ecount;
int bytes, i;
u8_t two_bytes[2];
phys_bytes phys_2bytes;
int odd_byte;
ecount = (count + 1) & ~1;
phys_2bytes = vir2phys(two_bytes);
odd_byte = 0;
dp_read_setup(dep, ecount, nic_addr);
i = 0;
while (count > 0) {
if (i >= IOVEC_NR) {
dp_next_iovec(iovp);
i = 0;
continue;
}
bytes = iovp->iod_iovec[i].iov_size;
if (bytes > count) bytes = count;
phys_user = numap(iovp->iod_proc_nr,
iovp->iod_iovec[i].iov_addr, bytes);
if (!phys_user) panic(UmapErrMsg);
if (odd_byte) {
phys_copy(phys_2bytes + 1, phys_user, (phys_bytes) 1);
count--;
bytes--;
phys_user++;
odd_byte = 0;
if (!bytes) continue;
}
ecount = bytes & ~1;
if (ecount != 0) {
phys_insw(dep->de_data_port, phys_user, ecount);
count -= ecount;
bytes -= ecount;
phys_user += ecount;
}
if (bytes) {
*(u16_t *) two_bytes = in_word(dep->de_data_port);
phys_copy(phys_2bytes, phys_user, (phys_bytes) 1);
count--;
bytes--;
phys_user++;
odd_byte = 1;
}
}
return;
}
u32_t *alloc_pagetable(phys_bytes *ph)
{
u32_t *ret;
#define PG_PAGETABLES 24
static u32_t pagetables[PG_PAGETABLES][256] __aligned(1024);
static int pt_inuse = 0;
if(pt_inuse >= PG_PAGETABLES) panic("no more pagetables");
assert(sizeof(pagetables[pt_inuse]) == 1024);
ret = pagetables[pt_inuse++];
*ph = vir2phys(ret);
return ret;
}
/*===========================================================================*
* QueueMess *
*===========================================================================*/
PRIVATE int QueueMess(endpoint_t ep, vir_bytes msg_lin, struct proc *dst)
{
int k;
phys_bytes addr;
NOREC_ENTER(queuemess);
/* Queue a message from the src process (in memory) to the dst
* process (using dst process table entry). Do actual copy to
* kernel here; it's an error if the copy fails into kernel.
*/
vmassert(!(dst->p_misc_flags & MF_DELIVERMSG));
vmassert(dst->p_delivermsg_lin);
vmassert(isokendpt(ep, &k));
#if 0
if(INMEMORY(dst)) {
PHYS_COPY_CATCH(msg_lin, dst->p_delivermsg_lin,
sizeof(message), addr);
if(!addr) {
PHYS_COPY_CATCH(vir2phys(&ep), dst->p_delivermsg_lin,
sizeof(ep), addr);
if(!addr) {
NOREC_RETURN(queuemess, OK);
}
}
}
#endif
PHYS_COPY_CATCH(msg_lin, vir2phys(&dst->p_delivermsg), sizeof(message), addr);
if(addr) {
NOREC_RETURN(queuemess, EFAULT);
}
dst->p_delivermsg.m_source = ep;
dst->p_misc_flags |= MF_DELIVERMSG;
NOREC_RETURN(queuemess, OK);
}
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC void main()
{
/* Start the ball rolling. */
struct boot_image *ip; /* boot image pointer */
register struct proc *rp; /* process pointer */
register struct priv *sp; /* privilege structure pointer */
register int i, s;
int hdrindex; /* index to array of a.out headers */
phys_clicks text_base;
vir_clicks text_clicks, data_clicks;
reg_t ktsb; /* kernel task stack base */
struct exec e_hdr; /* for a copy of an a.out header */
/* Initialize the interrupt controller. */
intr_init(1);
/* Clear the process table. Anounce each slot as empty and set up mappings
* for proc_addr() and proc_nr() macros. Do the same for the table with
* privilege structures for the system processes.
*/
for (rp = BEG_PROC_ADDR, i = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++i) {
rp->p_rts_flags = SLOT_FREE; /* initialize free slot */
rp->p_nr = i; /* proc number from ptr */
(pproc_addr + NR_TASKS)[i] = rp; /* proc ptr from number */
}
for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
sp->s_proc_nr = NONE; /* initialize as free */
sp->s_id = i; /* priv structure index */
ppriv_addr[i] = sp; /* priv ptr from number */
}
/* Set up proc table entries for processes in boot image. The stacks of the
* kernel tasks are initialized to an array in data space. The stacks
* of the servers have been added to the data segment by the monitor, so
* the stack pointer is set to the end of the data segment. All the
* processes are in low memory on the 8086. On the 386 only the kernel
* is in low memory, the rest is loaded in extended memory.
*/
/* Task stacks. */
ktsb = (reg_t) t_stack;
for (i=0; i < NR_BOOT_PROCS; ++i) {
ip = &image[i]; /* process' attributes */
rp = proc_addr(ip->proc_nr); /* get process pointer */
rp->p_max_priority = ip->priority; /* max scheduling priority */
rp->p_priority = ip->priority; /* current priority */
rp->p_quantum_size = ip->quantum; /* quantum size in ticks */
rp->p_ticks_left = ip->quantum; /* current credit */
strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
(void) get_priv(rp, (ip->flags & SYS_PROC)); /* assign structure */
priv(rp)->s_flags = ip->flags; /* process flags */
priv(rp)->s_trap_mask = ip->trap_mask; /* allowed traps */
priv(rp)->s_call_mask = ip->call_mask; /* kernel call mask */
priv(rp)->s_ipc_to.chunk[0] = ip->ipc_to; /* restrict targets */
if (iskerneln(proc_nr(rp))) { /* part of the kernel? */
if (ip->stksize > 0) { /* HARDWARE stack size is 0 */
rp->p_priv->s_stack_guard = (reg_t *) ktsb;
*rp->p_priv->s_stack_guard = STACK_GUARD;
}
ktsb += ip->stksize; /* point to high end of stack */
rp->p_reg.sp = ktsb; /* this task's initial stack ptr */
text_base = kinfo.code_base >> CLICK_SHIFT;
/* processes that are in the kernel */
hdrindex = 0; /* all use the first a.out header */
} else {
hdrindex = 1 + i-NR_TASKS; /* servers, drivers, INIT */
}
/* The bootstrap loader created an array of the a.out headers at
* absolute address 'aout'. Get one element to e_hdr.
*/
phys_copy(aout + hdrindex * A_MINHDR, vir2phys(&e_hdr),
(phys_bytes) A_MINHDR);
/* Convert addresses to clicks and build process memory map */
text_base = e_hdr.a_syms >> CLICK_SHIFT;
text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
if (!(e_hdr.a_flags & A_SEP)) text_clicks = 0; /* common I&D */
data_clicks = (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
rp->p_memmap[T].mem_phys = text_base;
rp->p_memmap[T].mem_len = text_clicks;
rp->p_memmap[D].mem_phys = text_base + text_clicks;
rp->p_memmap[D].mem_len = data_clicks;
rp->p_memmap[S].mem_phys = text_base + text_clicks + data_clicks;
rp->p_memmap[S].mem_vir = data_clicks; /* empty - stack is in data */
/* Set initial register values. The processor status word for tasks
* is different from that of other processes because tasks can
* access I/O; this is not allowed to less-privileged processes
*/
rp->p_reg.pc = (reg_t) ip->initial_pc;
rp->p_reg.psw = (iskernelp(rp)) ? INIT_TASK_PSW : INIT_PSW;
/* Initialize the server stack pointer. Take it down one word
* to give crtso.s something to use as "argc".
*/
if (isusern(proc_nr(rp))) { /* user-space process? */
rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
rp->p_memmap[S].mem_len) << CLICK_SHIFT;
rp->p_reg.sp -= sizeof(reg_t);
}
/* Set ready. The HARDWARE task is never ready. */
if (rp->p_nr != HARDWARE) {
rp->p_rts_flags = 0; /* runnable if no flags */
lock_enqueue(rp); /* add to scheduling queues */
} else {
rp->p_rts_flags = NO_MAP; /* prevent from running */
}
/* Code and data segments must be allocated in protected mode. */
alloc_segments(rp);
}
PUBLIC __dead void arch_shutdown(int how)
{
u16_t magic;
vm_stop();
/* Mask all interrupts, including the clock. */
outb( INT_CTLMASK, ~0);
if(minix_panicing) {
unsigned char unused_ch;
/* We're panicing? Then retrieve and decode currently
* loaded segment selectors.
*/
printseg("cs: ", 1, get_cpulocal_var(proc_ptr), read_cs());
printseg("ds: ", 0, get_cpulocal_var(proc_ptr), read_ds());
if(read_ds() != read_ss()) {
printseg("ss: ", 0, NULL, read_ss());
}
/* Printing is done synchronously over serial. */
if (do_serial_debug)
reset();
/* Print accumulated diagnostics buffer and reset. */
mb_cls();
mb_print("Minix panic. System diagnostics buffer:\n\n");
mb_print(kmess_buf);
mb_print("\nSystem has panicked, press any key to reboot");
while (!mb_read_char(&unused_ch))
;
reset();
}
#if USE_BOOTPARAM
if (how == RBT_DEFAULT) {
how = mon_return ? RBT_HALT : RBT_RESET;
}
if(how != RBT_RESET) {
/* return to boot monitor */
outb( INT_CTLMASK, 0);
outb( INT2_CTLMASK, 0);
/* Return to the boot monitor. Set
* the program if not already done.
*/
if (how != RBT_MONITOR)
arch_set_params("", 1);
if (mon_return)
arch_monitor();
/* monitor command with no monitor: reset or poweroff
* depending on the parameters
*/
if (how == RBT_MONITOR) {
how = RBT_RESET;
}
}
switch (how) {
case RBT_REBOOT:
case RBT_RESET:
/* Reset the system by forcing a processor shutdown.
* First stop the BIOS memory test by setting a soft
* reset flag.
*/
magic = STOP_MEM_CHECK;
phys_copy(vir2phys(&magic), SOFT_RESET_FLAG_ADDR,
SOFT_RESET_FLAG_SIZE);
reset();
NOT_REACHABLE;
case RBT_HALT:
/* Poweroff without boot monitor */
arch_bios_poweroff();
NOT_REACHABLE;
case RBT_PANIC:
/* Allow user to read panic message */
for (; ; ) halt_cpu();
NOT_REACHABLE;
default:
/* Not possible! trigger panic */
assert(how != RBT_MONITOR);
assert(how != RBT_DEFAULT);
assert(how < RBT_INVALID);
panic("unexpected value for how: %d", how);
NOT_REACHABLE;
}
#else /* !USE_BOOTPARAM */
/* Poweroff without boot monitor */
arch_bios_poweroff();
#endif
NOT_REACHABLE;
}
phys_bytes pg_load()
{
phys_bytes phpagedir = vir2phys(pagedir);
write_cr3(phpagedir);
return phpagedir;
}
PUBLIC __dead void arch_shutdown(int how)
{
static char mybuffer[sizeof(params_buffer)];
u16_t magic;
vm_stop();
/* Mask all interrupts, including the clock. */
outb( INT_CTLMASK, ~0);
if(minix_panicing) {
/* We're panicing? Then retrieve and decode currently
* loaded segment selectors.
*/
printseg("cs: ", 1, proc_ptr, read_cs());
printseg("ds: ", 0, proc_ptr, read_ds());
if(read_ds() != read_ss()) {
printseg("ss: ", 0, NULL, read_ss());
}
}
if (how == RBT_DEFAULT) {
how = mon_return ? RBT_HALT : RBT_RESET;
}
if(how != RBT_RESET) {
/* return to boot monitor */
outb( INT_CTLMASK, 0);
outb( INT2_CTLMASK, 0);
/* Return to the boot monitor. Set
* the program if not already done.
*/
if (how != RBT_MONITOR)
arch_set_params("", 1);
if(minix_panicing) {
int source, dest;
const char *lead = "echo \\n*** kernel messages:\\n";
const int leadlen = strlen(lead);
strcpy(mybuffer, lead);
#define DECSOURCE source = (source - 1 + _KMESS_BUF_SIZE) % _KMESS_BUF_SIZE
dest = sizeof(mybuffer)-1;
mybuffer[dest--] = '\0';
source = kmess.km_next;
DECSOURCE;
while(dest >= leadlen) {
const char c = kmess.km_buf[source];
if(c == '\n') {
mybuffer[dest--] = 'n';
mybuffer[dest] = '\\';
} else if(isprint(c) &&
c != '\'' && c != '"' &&
c != '\\' && c != ';') {
mybuffer[dest] = c;
} else mybuffer[dest] = ' ';
DECSOURCE;
dest--;
}
arch_set_params(mybuffer, strlen(mybuffer)+1);
}
if (mon_return)
arch_monitor();
/* monitor command with no monitor: reset or poweroff
* depending on the parameters
*/
if (how == RBT_MONITOR) {
mybuffer[0] = '\0';
arch_get_params(mybuffer, sizeof(mybuffer));
if (strstr(mybuffer, "boot") ||
strstr(mybuffer, "menu") ||
strstr(mybuffer, "reset"))
how = RBT_RESET;
else
how = RBT_HALT;
}
}
switch (how) {
case RBT_REBOOT:
case RBT_RESET:
/* Reset the system by forcing a processor shutdown.
* First stop the BIOS memory test by setting a soft
* reset flag.
*/
magic = STOP_MEM_CHECK;
phys_copy(vir2phys(&magic), SOFT_RESET_FLAG_ADDR,
SOFT_RESET_FLAG_SIZE);
reset();
NOT_REACHABLE;
case RBT_HALT:
/* Poweroff without boot monitor */
arch_bios_poweroff();
NOT_REACHABLE;
case RBT_PANIC:
/* Allow user to read panic message */
for (; ; ) halt_cpu();
NOT_REACHABLE;
default:
/* Not possible! trigger panic */
assert(how != RBT_MONITOR);
assert(how != RBT_DEFAULT);
assert(how < RBT_INVALID);
panic("unexpected value for how: %d", how);
NOT_REACHABLE;
}
NOT_REACHABLE;
}
/*init the first process*/
static void init_user_process()
{
TASK* p_task = NULL;
/*struct task_struct* p_proc = proc_table + NR_SYSTEM_PROCS;*/
struct task_struct *tsk = NULL;
union thread_union *thread_union = NULL;
int i,j,prio, eflags;
char privilege,rpl;
unsigned int k_base,k_limit;
get_kernel_map(&k_base,&k_limit);
/*privilege = PRIVILEGE_USER;*/
/*rpl = RPL_USER;*/
/*eflags = 0x1202;*/
/*prio = USER_PRIO;*/
privilege = PRIVILEGE_TASK;
rpl = RPL_TASK;
eflags = 0x1202;
prio = KERNEL_PRIOR;
/*for(i = 0;i < NR_USER_PROCS; ++i,++p_proc)*/
for(i = 0;i < NR_USER_PROCS; ++i)
{
p_task = user_proc_table + i ;
tsk = (struct task_struct *)kmem_get_obj(tsk_cachep);
if(tsk == NULL)
return;
thread_union = (union thread_union*)kmem_get_obj(thread_union_cachep);
if(thread_union == NULL)
return;
thread_union->thread_info.task = tsk;
tsk->state = TASK_RUNNING;
strcpy(tsk->command, p_task->command); // name of the process
if((tsk->pid = get_pidmap()) < 0)
return;
tsk->parent = NULL;
tsk->next = tsk->sibling = NULL;
for(j = 0; j < NR_SIGNALS;++j)
{
tsk->sig_action[j].sa_flags = 0;
tsk->sig_action[j].sa_handler = do_signal;
}
for(j = 0;j < NR_OPEN; ++j)
{
tsk->filp[j] = NULL;
}
tsk->signal = 0x0; //设置信号为空
tsk->ldt_sel = selector_ldt;
init_descriptor(&gdt[selector_ldt>>3],vir2phys(seg2phys(SELECTOR_KERNEL_DS), tsk->ldts),LDT_SIZE * sizeof(DESCRIPTOR) - 1,DA_LDT);
tsk->ldts[INDEX_LDT_C] = gdt[SELECTOR_KERNEL_CS >> 3];
tsk->ldts[INDEX_LDT_C].attr1 = DA_C | privilege << 5;// change the DPL
tsk->ldts[INDEX_LDT_D] = gdt[SELECTOR_KERNEL_DS >> 3];
tsk->ldts[INDEX_LDT_D].attr1 = DA_DRW | privilege<< 5;// change the DPL
/*init_descriptor(&tsk->ldts[INDEX_LDT_C],0,(k_base + k_limit) >> LIMIT_4K_SHIFT,DA_32 | DA_LIMIT_4K | DA_C| privilege <<5);*/
/*init_descriptor(&tsk->ldts[INDEX_LDT_D],0,(k_base + k_limit) >> LIMIT_4K_SHIFT,DA_32 | DA_LIMIT_4K | DA_DRW | privilege << 5);*/
char *stack = (char *)thread_union->stack;
tsk->regs.esp = (unsigned int)(stack + sizeof(union thread_union));
tsk->regs.cs = (unsigned int)(((8 * 0) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.ds = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.es = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.fs = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.ss = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.gs = (unsigned int)((SELECTOR_KERNEL_GS & SA_RPL_MASK) | rpl);
tsk->regs.eip = (unsigned int)p_task->initial_eip;
tsk->regs.eflags = eflags;
tsk->ticks = tsk->priority = prio;
tsk->sched_entity.vruntime = i;
tsk->sched_class = &rr_sched;
tsk->sched_class->enqueue_task(&(sched_rq),tsk,0,0);
p_task++;
selector_ldt += 1 << 3;
}
k_reenter = 0;
ticks = 0;
}
/*init the first process*/
static void init_kernel_thread()
{
TASK* p_task = NULL;
/*struct task_struct* p_proc = proc_table;*/
struct task_struct *tsk = NULL;
union thread_union *thread_union = NULL;
char* p_task_stack = task_stack + STACK_SIZE_TOTAL;
int i,j,prio,eflags;
char privilege,rpl;
unsigned int k_base,k_limit;
get_kernel_map(&k_base,&k_limit);
privilege = PRIVILEGE_TASK;
rpl = RPL_TASK;
eflags = 0x1202;
prio = KERNEL_PRIOR;
printk(" PrettyOS SoftIRQ.");
/*printk(" [email protected] .\n");*/
/*printk(" UESTC.\n");*/
/*disp_str("\t\tprocess init begins\n");*/
/*for(i = 0;i < NR_SYSTEM_PROCS ;++i, ++p_proc)*/
for(i = 0;i < NR_SYSTEM_PROCS ;++i)
{
p_task = task_table + i;
tsk = (struct task_struct *)kmem_get_obj(tsk_cachep);
if(tsk == NULL)
return;
thread_union = (union thread_union*)kmem_get_obj(thread_union_cachep);
if(thread_union == NULL)
return;
thread_union->thread_info.task = tsk;
tsk->state = TASK_RUNNING;
strcpy(tsk->command, p_task->command); // name of the process
if((tsk->pid = get_pidmap()) < 0)
return;
tsk->parent = NULL;
tsk->next = tsk->sibling = NULL;
/*proc_table[0].nr_tty = 0; // tty */
for(j = 0; j < NR_SIGNALS;++j)
{
tsk->sig_action[j].sa_flags = 0;
tsk->sig_action[j].sa_handler = do_signal;
}
for(j = 0;j < NR_OPEN; ++j)
{
tsk->filp[j] = NULL;
}
tsk->signal = 0x0; //设置信号为空
tsk->ldt_sel = selector_ldt;
init_descriptor(&gdt[selector_ldt>>3],vir2phys(seg2phys(SELECTOR_KERNEL_DS), tsk->ldts),LDT_SIZE * sizeof(DESCRIPTOR) - 1,DA_LDT);
init_descriptor(&tsk->ldts[INDEX_LDT_C],0,(k_base + k_limit) >> LIMIT_4K_SHIFT,DA_32 | DA_LIMIT_4K | DA_C| privilege <<5);
init_descriptor(&tsk->ldts[INDEX_LDT_D],0,(k_base + k_limit) >> LIMIT_4K_SHIFT,DA_32 | DA_LIMIT_4K | DA_DRW | privilege << 5);
tsk->regs.esp = (unsigned int)p_task_stack;
p_task_stack -= STACK_SIZE_DEFAULT;
tsk->regs.cs = (unsigned int)(((8 * 0) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.ds = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.es = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.fs = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.ss = (unsigned int)(((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | rpl);
tsk->regs.gs = (unsigned int)((SELECTOR_KERNEL_GS & SA_RPL_MASK) | rpl);
tsk->regs.eip = (unsigned int)p_task->initial_eip;
tsk->regs.eflags = eflags;
tsk->ticks = tsk->priority = prio;
tsk->sched_entity.vruntime = i;
tsk->sched_class = &rr_sched;
if(tsk->pid != INIT_PID)
tsk->sched_class->enqueue_task(&(sched_rq),tsk,0,0);
p_task++;
selector_ldt += 1 << 3;
}
k_reenter = 0;
ticks = 0;
}
//--------------------------------------------------------------------------
// init_prot
//--------------------------------------------------------------------------
void init_prot()
{
init_8259A();
// 全部初始化成中断门(没有陷阱门)
init_idt_desc(INT_VECTOR_DIVIDE, DA_386IGate,
divide_error, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_DEBUG, DA_386IGate,
single_step_exception, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_NMI, DA_386IGate,
nmi, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_BREAKPOINT, DA_386IGate,
breakpoint_exception, PRIVILEGE_USER);
init_idt_desc(INT_VECTOR_OVERFLOW, DA_386IGate,
overflow, PRIVILEGE_USER);
init_idt_desc(INT_VECTOR_BOUNDS, DA_386IGate,
bounds_check, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_INVAL_OP, DA_386IGate,
inval_opcode, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_NOT, DA_386IGate,
copr_not_available, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_DOUBLE_FAULT, DA_386IGate,
double_fault, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_SEG, DA_386IGate,
copr_seg_overrun, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_INVAL_TSS, DA_386IGate,
inval_tss, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_SEG_NOT, DA_386IGate,
segment_not_present, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_STACK_FAULT, DA_386IGate,
stack_exception, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_PROTECTION, DA_386IGate,
general_protection, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_PAGE_FAULT, DA_386IGate,
page_fault, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_COPROC_ERR, DA_386IGate,
copr_error, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 0, DA_386IGate,
hwint00, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 1, DA_386IGate,
hwint01, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 2, DA_386IGate,
hwint02, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 3, DA_386IGate,
hwint03, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 4, DA_386IGate,
hwint04, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 5, DA_386IGate,
hwint05, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 6, DA_386IGate,
hwint06, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ0 + 7, DA_386IGate,
hwint07, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 0, DA_386IGate,
hwint08, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 1, DA_386IGate,
hwint09, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 2, DA_386IGate,
hwint10, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 3, DA_386IGate,
hwint11, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 4, DA_386IGate,
hwint12, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 5, DA_386IGate,
hwint13, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 6, DA_386IGate,
hwint14, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_IRQ8 + 7, DA_386IGate,
hwint15, PRIVILEGE_KRNL);
init_idt_desc(INT_VECTOR_SYS_CALL, DA_386IGate,
sys_call, PRIVILEGE_USER);
//填充 GDT 中 TSS 这个描述符
memset(&tss, 0, sizeof(tss));
tss.ss0 = SELECTOR_KERNEL_DS;
init_descriptor(&gdt[INDEX_TSS],
vir2phys(seg2phys(SELECTOR_KERNEL_DS), &tss),
sizeof(tss) - 1,
DA_386TSS);
tss.iobase = sizeof(tss); // 没有I/O许可位图
// 填充 GDT 中进程的 LDT 的描述符
int i;
PROCESS* p_proc = proc_table;
u16 selector_ldt = INDEX_LDT_FIRST << 3;
for(i=0;i<NR_TASKS;i++){
init_descriptor(&gdt[selector_ldt>>3],
vir2phys(seg2phys(SELECTOR_KERNEL_DS),
proc_table[i].ldts),
LDT_SIZE * sizeof(DESCRIPTOR) - 1,
DA_LDT);
p_proc++;
selector_ldt += 1 << 3;
}
}
/**
* \brief Set up tables for protected mode
* All GDT slots are allocated at compile time
*/
void prot_init()
{
struct gate_table_s *gtp;
struct desctableptr_s *dtp;
unsigned ldt_index;
struct proc *rp;
static struct gate_table_s {
void (*gate)(void);
unsigned char vec_nr;
unsigned char privilege;
} gate_table[] = {
{ divide_error, DIVIDE_VECTOR, INTR_PRIVILEGE },
{ single_step_exception, DEBUG_VECTOR, INTR_PRIVILEGE },
{ nmi, NMI_VECTOR, INTR_PRIVILEGE },
{ breakpoint_exception, BREAKPOINT_VECTOR, USER_PRIVILEGE },
{ overflow, OVERFLOW_VECTOR, USER_PRIVILEGE },
{ bounds_check, BOUNDS_VECTOR, INTR_PRIVILEGE },
{ inval_opcode, INVAL_OP_VECTOR, INTR_PRIVILEGE },
{ copr_not_available, COPROC_NOT_VECTOR, INTR_PRIVILEGE },
{ double_fault, DOUBLE_FAULT_VECTOR, INTR_PRIVILEGE },
{ copr_seg_overrun, COPROC_SEG_VECTOR, INTR_PRIVILEGE },
{ inval_tss, INVAL_TSS_VECTOR, INTR_PRIVILEGE },
{ segment_not_present, SEG_NOT_VECTOR, INTR_PRIVILEGE },
{ stack_exception, STACK_FAULT_VECTOR, INTR_PRIVILEGE },
{ general_protection, PROTECTION_VECTOR, INTR_PRIVILEGE },
{ page_fault, PAGE_FAULT_VECTOR, INTR_PRIVILEGE },
{ copr_error, COPROC_ERR_VECTOR, INTR_PRIVILEGE },
{ hwint00, IRQ0_VECTOR + CLOCK_IRQ, INTR_PRIVILEGE },
{ hwint01, IRQ0_VECTOR + KEYBOARD_IRQ, INTR_PRIVILEGE },
{ hwint02, IRQ0_VECTOR + CASCADE_IRQ, INTR_PRIVILEGE },
{ hwint03, IRQ0_VECTOR + ETHER_IRQ, INTR_PRIVILEGE },
{ hwint04, IRQ0_VECTOR + RS232_IRQ, INTR_PRIVILEGE },
{ hwint05, IRQ0_VECTOR + 5, INTR_PRIVILEGE },
{ hwint06, IRQ0_VECTOR + 6, INTR_PRIVILEGE },
{ hwint07, IRQ0_VECTOR + 7, INTR_PRIVILEGE },
{ hwint08, IRQ0_VECTOR + 8, INTR_PRIVILEGE },
{ hwint09, IRQ0_VECTOR + 9, INTR_PRIVILEGE },
{ hwint10, IRQ0_VECTOR + 10, INTR_PRIVILEGE },
{ hwint11, IRQ0_VECTOR + 11, INTR_PRIVILEGE },
{ hwint12, IRQ0_VECTOR + 12, INTR_PRIVILEGE },
{ hwint13, IRQ0_VECTOR + 13, INTR_PRIVILEGE },
{ hwint14, IRQ0_VECTOR + IDE_IRQ, INTR_PRIVILEGE },
{ hwint15, IRQ0_VECTOR + 15, INTR_PRIVILEGE },
{ s_call, SYS_VECTOR, USER_PRIVILEGE }, // system call
{ level0_call, LEVEL0_VECTOR, TASK_PRIVILEGE },
};
/* since it is now in protected mode and it enters protected mode
* in boot loader where global segment descriptor is set up to
* map all physical memory, that is base is 0, and limit is MAX
* physical memory - 1
*
* so here when apply vir2phys ( kinfo.data_base + vir ), still
* get vir
*/
// Build gdt and idt pointers in GDT where the BIOS expects them
dtp = (struct desctableptr_s *) &gdt[GDT_INDEX];
*((u16_t *) dtp->limit) = (sizeof gdt) - 1;
*((u32_t *) dtp->base) = vir2phys(gdt);
dtp = (struct desctableptr_s *) &gdt[IDT_INDEX];
*((u16_t *) dtp->limit) = (sizeof idt) - 1;
*((u32_t *) dtp->base) = vir2phys(idt);
// Build segment descriptors for tasks and interrupt handlers
init_codeseg(&gdt[CS_INDEX], kinfo.code_base, kinfo.code_size, INTR_PRIVILEGE);
init_dataseg(&gdt[DS_INDEX], kinfo.data_base, kinfo.data_size, INTR_PRIVILEGE);
init_dataseg(&gdt[ES_INDEX], 0L, 0, TASK_PRIVILEGE);
// Build scratch descriptors for functions in klib88
init_dataseg(&gdt[DS_286_INDEX], 0L, 0, TASK_PRIVILEGE);
init_dataseg(&gdt[ES_286_INDEX], 0L, 0, TASK_PRIVILEGE);
/* Build local descriptors in GDT for LDT's in process table.
* The LDT's are allocated at compile time in the process table, and
* initialized whenever a process' map is initialized or changed.
*/
for (rp = BEG_PROC_ADDR, ldt_index = FIRST_LDT_INDEX; rp < END_PROC_ADDR; ++rp, ldt_index++)
{
init_dataseg(&gdt[ldt_index], vir2phys(rp->p_ldt), sizeof(rp->p_ldt), INTR_PRIVILEGE);
gdt[ldt_index].access = PRESENT | LDT;
rp->p_ldt_sel = ldt_index * DESC_SIZE;
}
/* Build main TSS.
* This is used only to record the stack pointer to be used after an interrupt.
* Actually it points to stackframe of proc
*
* The pointer is set up so that an interrupt automatically saves the
* current process's registers eip:cs:eflags:esp:ss in the correct slots in the
* process table.
*/
tss.ss0 = DS_SELECTOR;
init_dataseg(&gdt[TSS_INDEX], vir2phys(&tss), sizeof(tss), INTR_PRIVILEGE);
gdt[TSS_INDEX].access = PRESENT | (INTR_PRIVILEGE << DPL_SHIFT) | TSS_TYPE;
// Build descriptors for interrupt gates in IDT
for (gtp = &gate_table[0]; gtp < &gate_table[sizeof gate_table / sizeof gate_table[0]]; ++gtp)
{
int_gate(gtp->vec_nr, (vir_bytes) gtp->gate,
PRESENT | INT_GATE_TYPE | (gtp->privilege << DPL_SHIFT));
}
// Complete building of main TSS
tss.iobase = sizeof tss; // empty i/o permissions map
}
lock_enqueue(rp); /* add to scheduling queues */
} else {
rp->p_rts_flags = NO_MAP; /* prevent from running */
}
/* Code and data segments must be allocated in protected mode. */
alloc_segments(rp);
}
#if ENABLE_BOOTDEV
/* Expect an image of the boot device to be loaded into memory as well.
* The boot device is the last module that is loaded into memory, and,
* for example, can contain the root FS (useful for embedded systems).
*/
hdrindex ++;
phys_copy(aout + hdrindex * A_MINHDR,vir2phys(&e_hdr),(phys_bytes) A_MINHDR);
if (e_hdr.a_flags & A_IMG) {
kinfo.bootdev_base = e_hdr.a_syms;
kinfo.bootdev_size = e_hdr.a_data;
}
#endif
/* MINIX is now ready. All boot image processes are on the ready queue.
* Return to the assembly code to start running the current process.
*/
bill_ptr = proc_addr(IDLE); /* it has to point somewhere */
announce(); /* print MINIX startup banner */
restart();
}
/*===========================================================================*
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC void main()
{
/* Start the ball rolling. */
struct boot_image *ip; /* boot image pointer */
register struct proc *rp; /* process pointer */
register struct priv *sp; /* privilege structure pointer */
register int i, s;
// a.out 头部数组的索引.
int hdrindex; /* index to array of a.out headers */
phys_clicks text_base;
vir_clicks text_clicks, data_clicks;
// 内核任务栈的基地址(低端)
reg_t ktsb; /* kernel task stack base */
// 用来放置 a.out 头部的一个副本.
struct exec e_hdr; /* for a copy of an a.out header */
/* Initialize the interrupt controller. */
// 初始化 8259 中断控制器芯片.
intr_init(1);
/* Clear the process table. Anounce each slot as empty and set up mappings
* for proc_addr() and proc_nr() macros. Do the same for the table with
* privilege structures for the system processes.
*/
// 初如化进程表与进程指针表.
// BEG_PROC_ADDR: 进程表地址;
for (rp = BEG_PROC_ADDR, i = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++i) {
// 将进程表中每一项都设置为空闲.
rp->p_rts_flags = SLOT_FREE; /* initialize free slot */
// 进程号, i 的初值为 -NR_TASKS, 可见系统任务拥有负的进程号
rp->p_nr = i; /* proc number from ptr */
// 建立进程数组与进程指针数组之间的映射关系
(pproc_addr + NR_TASKS)[i] = rp; /* proc ptr from number */
}
// 初始化优先级表
for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
sp->s_proc_nr = NONE; /* initialize as free */
sp->s_id = i; /* priv structure index */
// 建立特权级表与特权级指针表之间的映射关系
ppriv_addr[i] = sp; /* priv ptr from number */
}
/* Set up proc table entries for tasks and servers. The stacks of the
* kernel tasks are initialized to an array in data space. The stacks
* of the servers have been added to the data segment by the monitor, so
* the stack pointer is set to the end of the data segment. All the
* processes are in low memory on the 8086. On the 386 only the kernel
* is in low memory, the rest is loaded in extended memory.
*/
/*
* 为任务和服务进程设置进程表项. 内核任务的栈被初始化成一个在数据空间中的
* 数组. 服务进程的栈已经由控制器添加到数据段中, 所有它们的栈指针开始时
* 指向数据段的末尾. 所有的进程都在 8086 的低内存. 对于 386, 只有内核在
* 低内存, 剩下的都在扩展内存中.
*/
/* Task stacks. */
/* 任务栈 */
ktsb = (reg_t) t_stack;
// 为那些包含在系统引导映像文件中的程序分配进程表项.
for (i=0; i < NR_BOOT_PROCS; ++i) {
ip = &image[i]; /* process' attributes */
// 获取进程指针
rp = proc_addr(ip->proc_nr); /* get process pointer */
// 最大调度优先级
rp->p_max_priority = ip->priority; /* max scheduling priority */
// 当前调度优先级
rp->p_priority = ip->priority; /* current priority */
// 时间片原子值
rp->p_quantum_size = ip->quantum; /* quantum size in ticks */
// 剩余时间片
rp->p_ticks_left = ip->quantum; /* current credit */
// 将程序名复制到进程表项中
strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
// 为进程分配一个特权级结构体, 即 从系统特权级表中分配一项
(void) get_priv(rp, (ip->flags & SYS_PROC)); /* assign structure */
// 初始化特权级结构体的标志.
priv(rp)->s_flags = ip->flags; /* process flags */
// 初始化特权级结构体的 允许的系统调用陷井
priv(rp)->s_trap_mask = ip->trap_mask; /* allowed traps */
priv(rp)->s_call_mask = ip->call_mask; /* kernel call mask */
// 初始化进程的消息发送位图
priv(rp)->s_ipc_to.chunk[0] = ip->ipc_to; /* restrict targets */
// 如果进程是内核任务
if (iskerneln(proc_nr(rp))) { /* part of the kernel? */
// 如果进程的栈大小大于 0, 设置进程的栈警戒字,
if (ip->stksize > 0) { /* HARDWARE stack size is 0 */
// 设置内核任务栈警戒字指针.
rp->p_priv->s_stack_guard = (reg_t *) ktsb;
// 指针运算符(->) 要比取值运行符 (*) 的优先级要高.
// 等价于:
// *(rp->p_priv->s_stack_guard) = STACK_GUARD
// 效果是在栈的最顶端(在低地址)放置一个特殊值,
// 这个值就是栈警戒字.
*rp->p_priv->s_stack_guard = STACK_GUARD;
}
ktsb += ip->stksize; /* point to high end of stack */
// 初始进程的栈指针
rp->p_reg.sp = ktsb; /* this task's initial stack ptr */
// kinfo ???
// 内核代码的基地址右移 CLICK_SHIFT 位, 赋给 text_base.
text_base = kinfo.code_base >> CLICK_SHIFT;
/* processes that are in the kernel */
// 内核任务使用同一个 a.out 头部信息
hdrindex = 0; /* all use the first a.out header */
} else {
// 非内核任务, 计算它的 a.out 头部数组索引, 因为 0 号项
// 留给了内核任务, 所以需 加 1.
hdrindex = 1 + i-NR_TASKS; /* servers, drivers, INIT */
}
/* The bootstrap loader created an array of the a.out headers at
* absolute address 'aout'. Get one element to e_hdr.
*/
/*
* 引导加载程序会在绝对地址 'aout' 处放置一个 a.out 头部数组.
* 从中取一项复制到 e_hdr.
*/
phys_copy(aout + hdrindex * A_MINHDR, vir2phys(&e_hdr),
(phys_bytes) A_MINHDR);
/* Convert addresses to clicks and build process memory map */
/* 将地址转换为以 click 为单位, 并建立进程内存映射 */
// 既然这里要设置 text_base, 那 146 行附近的
// text_base = kinfo.code_base >> CLICK_SHIFT;
// 岂不是多余的??
// 将 a.out 头部的符号表大小右移 CLICK_SHIFT 位,赋给 text_base.
text_base = e_hdr.a_syms >> CLICK_SHIFT;
// 计算程序文本段大小, 以 click 为单位, 上取整.
text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
// 如果 a.out 头部指明它的 I/D 是合并的 ???
if (!(e_hdr.a_flags & A_SEP)) text_clicks = 0; /* common I&D */
// 计算程序占用的内存量, 以 click 为单位, 上取整.
data_clicks = (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
// 初始化进程的内存映射数据结构
rp->p_memmap[T].mem_phys = text_base;
rp->p_memmap[T].mem_len = text_clicks;
rp->p_memmap[D].mem_phys = text_base + text_clicks;
rp->p_memmap[D].mem_len = data_clicks;
rp->p_memmap[S].mem_phys = text_base + text_clicks + data_clicks;
rp->p_memmap[S].mem_vir = data_clicks; /* empty - stack is in data */
/* Set initial register values. The processor status word for tasks
* is different from that of other processes because tasks can
* access I/O; this is not allowed to less-privileged processes
*/
/*
* 设置寄存器的初始值. 与其他进程相比, 内核任务的处理器状态字
* 稍有不同, 因为内核任务可以访问 I/O; 而对于非特权进来来说, 这是不
* 允许的.
*/
// 初始化进程的 PC 和 processor status word.
rp->p_reg.pc = (reg_t) ip->initial_pc;
rp->p_reg.psw = (iskernelp(rp)) ? INIT_TASK_PSW : INIT_PSW;
/* Initialize the server stack pointer. Take it down one word
* to give crtso.s something to use as "argc".
*/
/*
* 初始化服务器进程的栈指针. 下移一个字的空间, 使得 crtso.s 有
* 空间放置 "argc".
*/
if (isusern(proc_nr(rp))) { /* user-space process? */
rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
rp->p_memmap[S].mem_len) << CLICK_SHIFT;
rp->p_reg.sp -= sizeof(reg_t);
}
/* Set ready. The HARDWARE task is never ready. */
if (rp->p_nr != HARDWARE) {
// 如果进程不是 HARDWARE, 清空进程标志, 并加入调度队列.
rp->p_rts_flags = 0; /* runnable if no flags */
lock_enqueue(rp); /* add to scheduling queues */
} else {
// 对于 HARDWARE 任务, 则阻止其运行. ???
rp->p_rts_flags = NO_MAP; /* prevent from running */
}
/* Code and data segments must be allocated in protected mode. */
/* 数据与代码段必须在保护模式下分配 */
alloc_segments(rp);
}
void pg_info(reg_t *pagedir_ph, u32_t **pagedir_v)
{
*pagedir_ph = vir2phys(pagedir);
*pagedir_v = pagedir;
}
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC void main()
{
/* Start the ball rolling. */
register struct proc *rp;
register int t;
int hdrindex;
phys_clicks text_base;
vir_clicks text_clicks;
vir_clicks data_clicks;
phys_bytes phys_b;
reg_t ktsb; /* kernel task stack base */
struct memory *memp;
struct tasktab *ttp;
struct exec e_hdr;
licznik_elementow = 0;
/* Initialize the interrupt controller. */
intr_init(1);
/* Interpret memory sizes. */
mem_init();
/* Clear the process table.
* Set up mappings for proc_addr() and proc_number() macros.
*/
for (rp = BEG_PROC_ADDR, t = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++t) {
rp->p_nr = t; /* proc number from ptr */
(pproc_addr + NR_TASKS)[t] = rp; /* proc ptr from number */
}
/* Resolve driver selections in the task table. */
mapdrivers();
/* Set up proc table entries for tasks and servers. The stacks of the
* kernel tasks are initialized to an array in data space. The stacks
* of the servers have been added to the data segment by the monitor, so
* the stack pointer is set to the end of the data segment. All the
* processes are in low memory on the 8086. On the 386 only the kernel
* is in low memory, the rest is loaded in extended memory.
*/
/* Task stacks. */
ktsb = (reg_t) t_stack;
for (t = -NR_TASKS; t <= LOW_USER; ++t) {
rp = proc_addr(t); /* t's process slot */
ttp = &tasktab[t + NR_TASKS]; /* t's task attributes */
strcpy(rp->p_name, ttp->name);
if (t < 0) {
if (ttp->stksize > 0) {
rp->p_stguard = (reg_t *) ktsb;
*rp->p_stguard = STACK_GUARD;
}
ktsb += ttp->stksize;
rp->p_reg.sp = ktsb;
text_base = code_base >> CLICK_SHIFT;
/* tasks are all in the kernel */
hdrindex = 0; /* and use the first a.out header */
rp->p_priority = PPRI_TASK;
} else {
hdrindex = 1 + t; /* MM, FS, INIT follow the kernel */
rp->p_priority = t < LOW_USER ? PPRI_SERVER : PPRI_USER;
}
/* The bootstrap loader has created an array of the a.out headers at
* absolute address 'aout'.
*/
phys_copy(aout + hdrindex * A_MINHDR, vir2phys(&e_hdr),
(phys_bytes) A_MINHDR);
text_base = e_hdr.a_syms >> CLICK_SHIFT;
text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
if (!(e_hdr.a_flags & A_SEP)) text_clicks = 0; /* Common I&D */
data_clicks = (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
rp->p_map[T].mem_phys = text_base;
rp->p_map[T].mem_len = text_clicks;
rp->p_map[D].mem_phys = text_base + text_clicks;
rp->p_map[D].mem_len = data_clicks;
rp->p_map[S].mem_phys = text_base + text_clicks + data_clicks;
rp->p_map[S].mem_vir = data_clicks; /* empty - stack is in data */
/* Remove server memory from the free memory list. The boot monitor
* promises to put processes at the start of memory chunks.
*/
for (memp = mem; memp < &mem[NR_MEMS]; memp++) {
if (memp->base == text_base) {
memp->base += text_clicks + data_clicks;
memp->size -= text_clicks + data_clicks;
}
}
/* Set initial register values. */
rp->p_reg.pc = (reg_t) ttp->initial_pc;
rp->p_reg.psw = istaskp(rp) ? INIT_TASK_PSW : INIT_PSW;
if (t >= 0) {
/* Initialize the server stack pointer. Take it down one word
* to give crtso.s something to use as "argc".
*/
rp->p_reg.sp = (rp->p_map[S].mem_vir +
rp->p_map[S].mem_len) << CLICK_SHIFT;
rp->p_reg.sp -= sizeof(reg_t);
}
if (!isidlehardware(t)) lock_ready(rp); /* IDLE, HARDWARE neveready */
rp->p_flags = 0;
alloc_segments(rp);
}
void init_trap()
{
int i;
init_8259A();
//soft interrupt
set_trap_gate(INT_VECTOR_DIVIDE,divide_error);
set_trap_gate(INT_VECTOR_DEBUG, single_step_exception);
set_trap_gate(INT_VECTOR_NMI, nmi);
set_system_gate(INT_VECTOR_BREAKPOINT, breakpoint_exception);
set_system_gate(INT_VECTOR_OVERFLOW, overflow);
set_system_gate(INT_VECTOR_BOUNDS, bounds_check);
set_trap_gate(INT_VECTOR_INVAL_OP, inval_opcode);
set_trap_gate(INT_VECTOR_COPROC_NOT, copr_not_available);
set_trap_gate(INT_VECTOR_DOUBLE_FAULT, double_fault);
set_trap_gate(INT_VECTOR_COPROC_SEG, copr_seg_overrun);
set_trap_gate(INT_VECTOR_INVAL_TSS, inval_tss);
set_trap_gate(INT_VECTOR_SEG_NOT, segment_not_present);
set_trap_gate(INT_VECTOR_STACK_FAULT, stack_exception);
set_trap_gate(INT_VECTOR_PROTECTION, general_protection);
set_trap_gate(INT_VECTOR_PAGE_FAULT, page_fault);
set_trap_gate(INT_VECTOR_COPROC_ERR, copr_error);
// hard interrupt IRQ0-IRQ15
set_intr_gate(INT_VECTOR_IRQ0 + 0, clock_intr); //clock interrupt
set_intr_gate(INT_VECTOR_IRQ0 + 1, kb_intr); //keyboard interrupt
set_intr_gate(INT_VECTOR_IRQ0 + 2, hwint02);
set_intr_gate(INT_VECTOR_IRQ0 + 3, hwint03);
set_intr_gate(INT_VECTOR_IRQ0 + 4, hwint04);
set_intr_gate(INT_VECTOR_IRQ0 + 5, hwint05);
set_intr_gate(INT_VECTOR_IRQ0 + 6, hwint06);
set_intr_gate(INT_VECTOR_IRQ0 + 7, hwint07);
set_intr_gate(INT_VECTOR_IRQ8 + 0, hwint08);
set_intr_gate(INT_VECTOR_IRQ8 + 1, hwint09);
set_intr_gate(INT_VECTOR_IRQ8 + 2, hwint10);
set_intr_gate(INT_VECTOR_IRQ8 + 3, hwint11);
set_intr_gate(INT_VECTOR_IRQ8 + 4, hwint12);
set_intr_gate(INT_VECTOR_IRQ8 + 5, hwint13);
set_intr_gate(INT_VECTOR_IRQ8 + 6, hd_intr);//hard disk interrupt
set_intr_gate(INT_VECTOR_IRQ8 + 7, hwint15);
//init 80 interrupt
set_syscall_gate(INT_VECTOR_SYS_CALL, sys_call);
memset((char *)&tss, 0, sizeof(tss));
tss.ss0 = SELECTOR_KERNEL_DS;
//¿¿TSS
init_descriptor(&gdt[INDEX_TSS],
vir2phys(seg2phys(SELECTOR_KERNEL_DS), &tss),
sizeof(tss) - 1,
DA_386TSS);
tss.iobase = sizeof(tss);
PROCESS* p_proc = proc_table;
t16 selector_ldt = INDEX_LDT_FIRST << 3;
//¿¿GDT¿¿¿¿¿¿¿LDT
for(i=0;i<NR_SYSTEM_PROCS + NR_USER_PROCS;i++)
{
init_descriptor(&gdt[selector_ldt>>3],
vir2phys(seg2phys(SELECTOR_KERNEL_DS), proc_table[i].ldts),
LDT_SIZE * sizeof(DESCRIPTOR) - 1,
DA_LDT);
p_proc++;
selector_ldt += 1 << 3;
}
}