/*===========================================================================*
* newmap *
*===========================================================================*/
int newmap(struct proc *caller, struct proc *rp, struct mem_map *map_ptr)
{
int r;
/* Fetch the memory map. */
if((r=data_copy(caller->p_endpoint, (vir_bytes) map_ptr,
KERNEL, (vir_bytes) rp->p_memmap, sizeof(rp->p_memmap))) != OK) {
printf("newmap: data_copy failed! (%d)\n", r);
return r;
}
alloc_segments(rp);
return(OK);
}
/*===========================================================================*
* 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);
}
/*===========================================================================*
* do_update *
*===========================================================================*/
PUBLIC int do_update(struct proc * caller, message * m_ptr)
{
/* Handle sys_update(). Update a process into another by swapping their process
* slots.
*/
endpoint_t src_e, dst_e;
int src_p, dst_p;
struct proc *src_rp, *dst_rp;
struct priv *src_privp, *dst_privp;
struct proc orig_src_proc;
struct proc orig_dst_proc;
struct priv orig_src_priv;
struct priv orig_dst_priv;
int i;
/* Lookup slots for source and destination process. */
src_e = m_ptr->SYS_UPD_SRC_ENDPT;
if(!isokendpt(src_e, &src_p)) {
return EINVAL;
}
src_rp = proc_addr(src_p);
src_privp = priv(src_rp);
if(!(src_privp->s_flags & SYS_PROC)) {
return EPERM;
}
dst_e = m_ptr->SYS_UPD_DST_ENDPT;
if(!isokendpt(dst_e, &dst_p)) {
return EINVAL;
}
dst_rp = proc_addr(dst_p);
dst_privp = priv(dst_rp);
if(!(dst_privp->s_flags & SYS_PROC)) {
return EPERM;
}
/* Check if processes are updatable. */
if(!proc_is_updatable(src_rp) || !proc_is_updatable(dst_rp)) {
return EBUSY;
}
#if DEBUG
printf("do_update: updating %d (%s, %d, %d) into %d (%s, %d, %d)\n",
src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
proc_stacktrace(src_rp);
proc_stacktrace(dst_rp);
printf("do_update: curr ptproc %d\n", get_cpulocal_var(ptproc)->p_endpoint);
#endif
/* Let destination inherit the target mask from source. */
for (i=0; i < NR_SYS_PROCS; i++) {
if (get_sys_bit(priv(src_rp)->s_ipc_to, i)) {
set_sendto_bit(dst_rp, i);
}
}
/* Save existing data. */
orig_src_proc = *src_rp;
orig_src_priv = *(priv(src_rp));
orig_dst_proc = *dst_rp;
orig_dst_priv = *(priv(dst_rp));
/* Swap slots. */
*src_rp = orig_dst_proc;
*src_privp = orig_dst_priv;
*dst_rp = orig_src_proc;
*dst_privp = orig_src_priv;
/* Adjust process slots. */
adjust_proc_slot(src_rp, &orig_src_proc);
adjust_proc_slot(dst_rp, &orig_dst_proc);
/* Adjust privilege slots. */
adjust_priv_slot(priv(src_rp), &orig_src_priv);
adjust_priv_slot(priv(dst_rp), &orig_dst_priv);
/* Swap global process slot addresses. */
swap_proc_slot_pointer(get_cpulocal_var_ptr(ptproc), src_rp, dst_rp);
/* Fix segments. */
alloc_segments(src_rp);
alloc_segments(dst_rp);
prot_init();
#if DEBUG
printf("do_update: updated %d (%s, %d, %d) into %d (%s, %d, %d)\n",
src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
proc_stacktrace(src_rp);
proc_stacktrace(dst_rp);
printf("do_update: curr ptproc %d\n", get_cpulocal_var(ptproc)->p_endpoint);
#endif
return 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);
}
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main(void)
{
/* Start the ball rolling. */
struct boot_image *ip; /* boot image pointer */
register struct proc *rp; /* process pointer */
register int i, j;
size_t argsz; /* size of arguments passed to crtso on stack */
BKL_LOCK();
/* Global value to test segment sanity. */
magictest = MAGICTEST;
DEBUGEXTRA(("main()\n"));
proc_init();
/* Set up proc table entries for processes in boot image. 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.
*/
for (i=0; i < NR_BOOT_PROCS; ++i) {
int schedulable_proc;
proc_nr_t proc_nr;
int ipc_to_m, kcalls;
sys_map_t map;
ip = &image[i]; /* process' attributes */
DEBUGEXTRA(("initializing %s... ", ip->proc_name));
rp = proc_addr(ip->proc_nr); /* get process pointer */
ip->endpoint = rp->p_endpoint; /* ipc endpoint */
make_zero64(rp->p_cpu_time_left);
strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
reset_proc_accounting(rp);
/* See if this process is immediately schedulable.
* In that case, set its privileges now and allow it to run.
* Only kernel tasks and the root system process get to run immediately.
* All the other system processes are inhibited from running by the
* RTS_NO_PRIV flag. They can only be scheduled once the root system
* process has set their privileges.
*/
proc_nr = proc_nr(rp);
schedulable_proc = (iskerneln(proc_nr) || isrootsysn(proc_nr));
if(schedulable_proc) {
/* Assign privilege structure. Force a static privilege id. */
(void) get_priv(rp, static_priv_id(proc_nr));
/* Priviliges for kernel tasks. */
if(iskerneln(proc_nr)) {
/* Privilege flags. */
priv(rp)->s_flags = (proc_nr == IDLE ? IDL_F : TSK_F);
/* Allowed traps. */
priv(rp)->s_trap_mask = (proc_nr == CLOCK
|| proc_nr == SYSTEM ? CSK_T : TSK_T);
ipc_to_m = TSK_M; /* allowed targets */
kcalls = TSK_KC; /* allowed kernel calls */
}
/* Priviliges for the root system process. */
else if(isrootsysn(proc_nr)) {
priv(rp)->s_flags= RSYS_F; /* privilege flags */
priv(rp)->s_trap_mask= SRV_T; /* allowed traps */
ipc_to_m = SRV_M; /* allowed targets */
kcalls = SRV_KC; /* allowed kernel calls */
priv(rp)->s_sig_mgr = SRV_SM; /* signal manager */
rp->p_priority = SRV_Q; /* priority queue */
rp->p_quantum_size_ms = SRV_QT; /* quantum size */
}
/* Priviliges for ordinary process. */
else {
NOT_REACHABLE;
}
/* Fill in target mask. */
memset(&map, 0, sizeof(map));
if (ipc_to_m == ALL_M) {
for(j = 0; j < NR_SYS_PROCS; j++)
set_sys_bit(map, j);
}
fill_sendto_mask(rp, &map);
/* Fill in kernel call mask. */
for(j = 0; j < SYS_CALL_MASK_SIZE; j++) {
priv(rp)->s_k_call_mask[j] = (kcalls == NO_C ? 0 : (~0));
}
}
else {
/* Don't let the process run for now. */
RTS_SET(rp, RTS_NO_PRIV | RTS_NO_QUANTUM);
}
rp->p_memmap[T].mem_vir = ABS2CLICK(ip->memmap.text_vaddr);
rp->p_memmap[T].mem_phys = ABS2CLICK(ip->memmap.text_paddr);
rp->p_memmap[T].mem_len = ABS2CLICK(ip->memmap.text_bytes);
rp->p_memmap[D].mem_vir = ABS2CLICK(ip->memmap.data_vaddr);
rp->p_memmap[D].mem_phys = ABS2CLICK(ip->memmap.data_paddr);
rp->p_memmap[D].mem_len = ABS2CLICK(ip->memmap.data_bytes);
rp->p_memmap[S].mem_phys = ABS2CLICK(ip->memmap.data_paddr +
ip->memmap.data_bytes +
ip->memmap.stack_bytes);
rp->p_memmap[S].mem_vir = ABS2CLICK(ip->memmap.data_vaddr +
ip->memmap.data_bytes +
ip->memmap.stack_bytes);
rp->p_memmap[S].mem_len = 0;
/* 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 = ip->memmap.entry;
rp->p_reg.psw = (iskerneln(proc_nr)) ? INIT_TASK_PSW : INIT_PSW;
/* Initialize the server stack pointer. Take it down three words
* to give crtso.s something to use as "argc", "argv" and "envp".
*/
if (isusern(proc_nr)) { /* user-space process? */
rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
rp->p_memmap[S].mem_len) << CLICK_SHIFT;
argsz = 3 * sizeof(reg_t);
rp->p_reg.sp -= argsz;
phys_memset(rp->p_reg.sp -
(rp->p_memmap[S].mem_vir << CLICK_SHIFT) +
(rp->p_memmap[S].mem_phys << CLICK_SHIFT),
0, argsz);
}
/* scheduling functions depend on proc_ptr pointing somewhere. */
if(!get_cpulocal_var(proc_ptr))
get_cpulocal_var(proc_ptr) = rp;
/* If this process has its own page table, VM will set the
* PT up and manage it. VM will signal the kernel when it has
* done this; until then, don't let it run.
*/
if(ip->flags & PROC_FULLVM)
rp->p_rts_flags |= RTS_VMINHIBIT;
rp->p_rts_flags |= RTS_PROC_STOP;
rp->p_rts_flags &= ~RTS_SLOT_FREE;
alloc_segments(rp);
DEBUGEXTRA(("done\n"));
}
#define IPCNAME(n) { \
assert((n) >= 0 && (n) <= IPCNO_HIGHEST); \
assert(!ipc_call_names[n]); \
ipc_call_names[n] = #n; \
}
IPCNAME(SEND);
IPCNAME(RECEIVE);
IPCNAME(SENDREC);
IPCNAME(NOTIFY);
IPCNAME(SENDNB);
IPCNAME(SENDA);
/* Architecture-dependent initialization. */
DEBUGEXTRA(("arch_init()... "));
arch_init();
DEBUGEXTRA(("done\n"));
/* System and processes initialization */
DEBUGEXTRA(("system_init()... "));
system_init();
DEBUGEXTRA(("done\n"));
#ifdef CONFIG_SMP
if (config_no_apic) {
BOOT_VERBOSE(printf("APIC disabled, disables SMP, using legacy PIC\n"));
smp_single_cpu_fallback();
} else if (config_no_smp) {
BOOT_VERBOSE(printf("SMP disabled, using legacy PIC\n"));
smp_single_cpu_fallback();
} else {
smp_init();
/*
* if smp_init() returns it means that it failed and we try to finish
* single CPU booting
*/
bsp_finish_booting();
}
#else
/*
* if configured for a single CPU, we are already on the kernel stack which we
* are going to use everytime we execute kernel code. We finish booting and we
* never return here
*/
bsp_finish_booting();
#endif
NOT_REACHABLE;
return 1;
}
/*===========================================================================*
* 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 main(void)
{
/* 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, j;
int hdrindex; /* index to array of a.out headers */
phys_clicks text_base;
vir_clicks text_clicks, data_clicks, st_clicks;
reg_t ktsb; /* kernel task stack base */
struct exec *e_hdr = 0; /* for a copy of an a.out header */
/* Global value to test segment sanity. */
magictest = MAGICTEST;
/* 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 = RTS_SLOT_FREE; /* initialize free slot */
#ifdef CONFIG_DEBUG_KERNEL_SCHED_CHECK
rp->p_magic = PMAGIC;
#endif
rp->p_nr = i; /* proc number from ptr */
rp->p_endpoint = _ENDPOINT(0, rp->p_nr); /* generation no. 0 */
}
for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
sp->s_proc_nr = ENDPT_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) {
int schedulable_proc, proc_nr;
int ipc_to_m, kcalls;
ip = &image[i]; /* process' attributes */
rp = proc_addr(ip->proc_nr); /* get process pointer */
ip->endpoint = rp->p_endpoint; /* ipc endpoint */
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 */
/* See if this process is immediately schedulable.
* In that case, set its privileges now and allow it to run.
* Only kernel tasks and the root system process get to run immediately.
* All the other system processes are inhibited from running by the
* RTS_NO_PRIV flag. They can only be scheduled once the root system
* process has set their privileges.
*/
proc_nr = proc_nr(rp);
schedulable_proc = (iskerneln(proc_nr) || isrootsysn(proc_nr));
if(schedulable_proc) {
/* Assign privilege structure. Force a static privilege id. */
(void) get_priv(rp, static_priv_id(proc_nr));
/* Priviliges for kernel tasks. */
if(iskerneln(proc_nr)) {
/* Privilege flags. */
priv(rp)->s_flags = (proc_nr == IDLE ? IDL_F : TSK_F);
/* Allowed traps. */
priv(rp)->s_trap_mask = (proc_nr == CLOCK
|| proc_nr == SYSTEM ? CSK_T : TSK_T);
ipc_to_m = TSK_M; /* allowed targets */
kcalls = TSK_KC; /* allowed kernel calls */
} else if(isrootsysn(proc_nr)) {
/* Priviliges for the root system process. */
priv(rp)->s_flags= RSYS_F; /* privilege flags */
priv(rp)->s_trap_mask= RSYS_T; /* allowed traps */
ipc_to_m = RSYS_M; /* allowed targets */
kcalls = RSYS_KC; /* allowed kernel calls */
}
/* Fill in target mask. */
for (j=0; j < NR_SYS_PROCS; j++) {
if (ipc_to_m & (1 << j))
set_sendto_bit(rp, j);
else
unset_sendto_bit(rp, j);
}
/* Fill in kernel call mask. */
for(j = 0; j < CALL_MASK_SIZE; j++) {
priv(rp)->s_k_call_mask[j] = (kcalls == NO_C ? 0 : (~0));
}
} else {
/*Don't let the process run for now. */
RTS_SET(rp, RTS_NO_PRIV);
}
if (iskerneln(proc_nr)) { /* 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 */
hdrindex = 0; /* all use the first a.out header */
} else {
hdrindex = 1 + i-NR_TASKS; /* system/user processes */
}
/* Architecture-specific way to find out aout header of this
* boot process.
*/
e_hdr = arch_get_aout_header(hdrindex);
/* Convert addresses to clicks and build process memory map */
text_base = e_hdr->a_syms >> CLICK_SHIFT;
st_clicks= (e_hdr->a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
data_clicks = (e_hdr->a_text + e_hdr->a_data + e_hdr->a_bss + CLICK_SIZE-1) >> CLICK_SHIFT;
text_clicks = 0;
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 + st_clicks;
rp->p_memmap[S].mem_vir = st_clicks;
rp->p_memmap[S].mem_len = 0;
/* Patch (override) the non-kernel process' entry points in image table. The
* image table is located in kernel/kernel_syms.c. The kernel processes like
* IDLE, SYSTEM, CLOCK, HARDWARE are not changed because they are part of kernel
* and the entry points are set at compilation time. In case of IDLE or HARDWARE
* the entry point can be ignored becasue they never run (set RTS_PROC_STOP).
*/
if (!iskerneln(proc_nr(rp)))
ip->initial_pc = (task_t*)e_hdr->a_entry;
/* 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 = (iskerneln(proc_nr)) ? INIT_TASK_PSW : INIT_PSW;
/* Initialize the server stack pointer. Take it down one word
* to give crtso.s something to use as "argc","argv" and "envp".
*/
if (isusern(proc_nr)) { /* 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 -= 3*sizeof(reg_t);
}
/* scheduling functions depend on proc_ptr pointing somewhere. */
if(!proc_ptr)
proc_ptr = rp;
/* If this process has its own page table, VM will set the
* PT up and manage it. VM will signal the kernel when it has
* done this; until then, don't let it run.
*/
if(ip->flags & PROC_FULLVM)
RTS_SET(rp, RTS_VMINHIBIT);
/* IDLE & HARDWARE task is never put on a run queue as it is
* never ready to run.
*/
if (rp->p_nr == HARDWARE)
RTS_SET(rp, RTS_PROC_STOP);
if (rp->p_nr == IDLE)
RTS_SET(rp, RTS_PROC_STOP);
RTS_UNSET(rp, RTS_SLOT_FREE); /* remove RTS_SLOT_FREE and schedule */
alloc_segments(rp);
} /* for */
/* Architecture-dependent initialization. */
arch_init();
#ifdef CONFIG_DEBUG_KERNEL_STATS_PROFILE
sprofiling = 0; /* we're not profiling until instructed to */
#endif
cprof_procs_no = 0; /* init nr of hash table slots used */
#ifdef CONFIG_IDLE_TSC
idle_tsc = cvu64(0);
#endif
vm_running = 0;
krandom.random_sources = RANDOM_SOURCES;
krandom.random_elements = RANDOM_ELEMENTS;
/* Nucleos 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 Nucleos startup banner */
/*
* enable timer interrupts and clock task on the boot CPU
*/
if (boot_cpu_init_timer(system_hz)) {
kernel_panic("FATAL : failed to initialize timer interrupts, "
"cannot continue without any clock source!",
NO_NUM);
}
/* Warnings for sanity checks that take time. These warnings are printed
* so it's a clear warning no full release should be done with them
* enabled.
*/
#ifdef CONFIG_DEBUG_KERNEL_SCHED_CHECK
FIXME("CONFIG_DEBUG_KERNEL_SCHED_CHECK enabled");
#endif
#ifdef CONFIG_DEBUG_KERNEL_VMASSERT
FIXME("CONFIG_DEBUG_KERNEL_VMASSERT enabled");
#endif
#ifdef CONFIG_DEBUG_PROC_CHECK
FIXME("PROC check enabled");
#endif
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, j, s;
int hdrindex; /* index to array of a.out headers */
phys_clicks text_base;
vir_clicks text_clicks, data_clicks, st_clicks;
reg_t ktsb; /* kernel task stack base */
struct exec e_hdr; /* for a copy of an a.out header */
/* Architecture-dependent initialization. */
arch_init();
/* Global value to test segment sanity. */
magictest = MAGICTEST;
/* 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 */
#if DEBUG_SCHED_CHECK
rp->p_magic = PMAGIC;
#endif
rp->p_nr = i; /* proc number from ptr */
rp->p_endpoint = _ENDPOINT(0, rp->p_nr); /* generation no. 0 */
}
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) {
int ci;
bitchunk_t fv;
ip = &image[i]; /* process' attributes */
rp = proc_addr(ip->proc_nr); /* get process pointer */
ip->endpoint = rp->p_endpoint; /* ipc endpoint */
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 */
/* Warn about violations of the boot image table order consistency. */
if (priv_id(rp) != s_nr_to_id(ip->proc_nr) && (ip->flags & SYS_PROC))
kprintf("Warning: boot image table has wrong process order\n");
/* Initialize call mask bitmap from unordered set.
* A single SYS_ALL_CALLS is a special case - it
* means all calls are allowed.
*/
if(ip->nr_k_calls == 1 && ip->k_calls[0] == SYS_ALL_CALLS)
fv = ~0; /* fill call mask */
else
fv = 0; /* clear call mask */
for(ci = 0; ci < CALL_MASK_SIZE; ci++) /* fill or clear call mask */
priv(rp)->s_k_call_mask[ci] = fv;
if(!fv) /* not all full? enter calls bit by bit */
for(ci = 0; ci < ip->nr_k_calls; ci++)
SET_BIT(priv(rp)->s_k_call_mask,
ip->k_calls[ci]-KERNEL_CALL);
for (j = 0; j < NR_SYS_PROCS && j < BITCHUNK_BITS; j++)
if (ip->ipc_to & (1 << j))
set_sendto_bit(rp, j); /* 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 */
hdrindex = 0; /* all use the first a.out header */
} else {
hdrindex = 1 + i-NR_TASKS; /* servers, drivers, INIT */
}
/* Architecture-specific way to find out aout header of this
* boot process.
*/
arch_get_aout_headers(hdrindex, &e_hdr);
/* 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;
data_clicks = (e_hdr.a_data+e_hdr.a_bss + CLICK_SIZE-1) >> CLICK_SHIFT;
st_clicks= (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
if (!(e_hdr.a_flags & A_SEP))
{
data_clicks= (e_hdr.a_text+e_hdr.a_data+e_hdr.a_bss +
CLICK_SIZE-1) >> CLICK_SHIFT;
text_clicks = 0; /* common I&D */
}
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 + st_clicks;
rp->p_memmap[S].mem_vir = st_clicks;
rp->p_memmap[S].mem_len = 0;
/* 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);
}
/* scheduling functions depend on proc_ptr pointing somewhere. */
if(!proc_ptr) proc_ptr = rp;
/* If this process has its own page table, VM will set the
* PT up and manage it. VM will signal the kernel when it has
* done this; until then, don't let it run.
*/
if(priv(rp)->s_flags & PROC_FULLVM)
RTS_SET(rp, VMINHIBIT);
/* Set ready. The HARDWARE task is never ready. */
if (rp->p_nr == HARDWARE) RTS_SET(rp, PROC_STOP);
RTS_UNSET(rp, SLOT_FREE); /* remove SLOT_FREE and schedule */
alloc_segments(rp);
}
