2e89eb5270
any number of kernel calls. Allowed kernel calls are stored in table.c for every image process as a variably-sized array of allowed calls. This is used to fill the bitmap of size determined at compile time by the number of kernel calls. This filling is done by main.c. There is a special call called SYS_ALL_CALLS which fills the bitmap of allowed calls completely, if that is the only entry in the array.
281 lines
10 KiB
C
Executable file
281 lines
10 KiB
C
Executable file
/* This file contains the main program of MINIX as well as its shutdown code.
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* The routine main() initializes the system and starts the ball rolling by
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* setting up the process table, interrupt vectors, and scheduling each task
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* to run to initialize itself.
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* The routine shutdown() does the opposite and brings down MINIX.
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*
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* The entries into this file are:
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* main: MINIX main program
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* prepare_shutdown: prepare to take MINIX down
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*
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* Changes:
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* Nov 24, 2004 simplified main() with system image (Jorrit N. Herder)
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* Aug 20, 2004 new prepare_shutdown() and shutdown() (Jorrit N. Herder)
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*/
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#include "kernel.h"
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#include <signal.h>
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#include <string.h>
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#include <unistd.h>
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#include <a.out.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/endpoint.h>
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#include "proc.h"
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/* Prototype declarations for PRIVATE functions. */
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FORWARD _PROTOTYPE( void announce, (void));
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FORWARD _PROTOTYPE( void shutdown, (timer_t *tp));
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC void main()
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{
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/* Start the ball rolling. */
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struct boot_image *ip; /* boot image pointer */
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register struct proc *rp; /* process pointer */
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register struct priv *sp; /* privilege structure pointer */
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register int i, s;
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int hdrindex; /* index to array of a.out headers */
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phys_clicks text_base;
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vir_clicks text_clicks, data_clicks, st_clicks;
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reg_t ktsb; /* kernel task stack base */
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struct exec e_hdr; /* for a copy of an a.out header */
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/* Initialize the interrupt controller. */
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intr_init(1);
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/* Clear the process table. Anounce each slot as empty and set up mappings
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* for proc_addr() and proc_nr() macros. Do the same for the table with
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* privilege structures for the system processes.
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*/
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for (rp = BEG_PROC_ADDR, i = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++i) {
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rp->p_rts_flags = SLOT_FREE; /* initialize free slot */
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rp->p_nr = i; /* proc number from ptr */
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rp->p_endpoint = _ENDPOINT(0, rp->p_nr); /* generation no. 0 */
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(pproc_addr + NR_TASKS)[i] = rp; /* proc ptr from number */
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}
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for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
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sp->s_proc_nr = NONE; /* initialize as free */
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sp->s_id = i; /* priv structure index */
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ppriv_addr[i] = sp; /* priv ptr from number */
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}
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/* Set up proc table entries for processes in boot image. The stacks of the
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* kernel tasks are initialized to an array in data space. The stacks
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* of the servers have been added to the data segment by the monitor, so
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* the stack pointer is set to the end of the data segment. All the
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* processes are in low memory on the 8086. On the 386 only the kernel
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* is in low memory, the rest is loaded in extended memory.
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*/
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/* Task stacks. */
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ktsb = (reg_t) t_stack;
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for (i=0; i < NR_BOOT_PROCS; ++i) {
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int ci;
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bitchunk_t fv;
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ip = &image[i]; /* process' attributes */
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rp = proc_addr(ip->proc_nr); /* get process pointer */
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ip->endpoint = rp->p_endpoint; /* ipc endpoint */
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rp->p_max_priority = ip->priority; /* max scheduling priority */
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rp->p_priority = ip->priority; /* current priority */
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rp->p_quantum_size = ip->quantum; /* quantum size in ticks */
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rp->p_ticks_left = ip->quantum; /* current credit */
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strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
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(void) get_priv(rp, (ip->flags & SYS_PROC)); /* assign structure */
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priv(rp)->s_flags = ip->flags; /* process flags */
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priv(rp)->s_trap_mask = ip->trap_mask; /* allowed traps */
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/* Initialize call mask bitmap from unordered set.
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* A single SYS_ALL_CALLS is a special case - it
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* means all calls are allowed.
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*/
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if(ip->nr_k_calls == 1 && ip->k_calls[0] == SYS_ALL_CALLS)
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fv = ~0; /* fill call mask */
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else
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fv = 0; /* clear call mask */
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for(ci = 0; ci < CALL_MASK_SIZE; ci++) /* fill or clear call mask */
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priv(rp)->s_k_call_mask[ci] = fv;
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if(!fv) /* not all full? enter calls bit by bit */
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for(ci = 0; ci < ip->nr_k_calls; ci++)
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SET_BIT(priv(rp)->s_k_call_mask,
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ip->k_calls[ci]-KERNEL_CALL);
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priv(rp)->s_ipc_to.chunk[0] = ip->ipc_to; /* restrict targets */
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if (iskerneln(proc_nr(rp))) { /* part of the kernel? */
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if (ip->stksize > 0) { /* HARDWARE stack size is 0 */
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rp->p_priv->s_stack_guard = (reg_t *) ktsb;
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*rp->p_priv->s_stack_guard = STACK_GUARD;
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}
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ktsb += ip->stksize; /* point to high end of stack */
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rp->p_reg.sp = ktsb; /* this task's initial stack ptr */
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text_base = kinfo.code_base >> CLICK_SHIFT;
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/* processes that are in the kernel */
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hdrindex = 0; /* all use the first a.out header */
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} else {
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hdrindex = 1 + i-NR_TASKS; /* servers, drivers, INIT */
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}
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/* The bootstrap loader created an array of the a.out headers at
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* absolute address 'aout'. Get one element to e_hdr.
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*/
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phys_copy(aout + hdrindex * A_MINHDR, vir2phys(&e_hdr),
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(phys_bytes) A_MINHDR);
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/* Convert addresses to clicks and build process memory map */
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text_base = e_hdr.a_syms >> CLICK_SHIFT;
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text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
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data_clicks = (e_hdr.a_data+e_hdr.a_bss + CLICK_SIZE-1) >> CLICK_SHIFT;
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st_clicks= (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
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if (!(e_hdr.a_flags & A_SEP))
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{
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data_clicks= (e_hdr.a_text+e_hdr.a_data+e_hdr.a_bss +
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CLICK_SIZE-1) >> CLICK_SHIFT;
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text_clicks = 0; /* common I&D */
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}
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rp->p_memmap[T].mem_phys = text_base;
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rp->p_memmap[T].mem_len = text_clicks;
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rp->p_memmap[D].mem_phys = text_base + text_clicks;
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rp->p_memmap[D].mem_len = data_clicks;
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rp->p_memmap[S].mem_phys = text_base + text_clicks + st_clicks;
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rp->p_memmap[S].mem_vir = st_clicks;
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rp->p_memmap[S].mem_len = 0;
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/* Set initial register values. The processor status word for tasks
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* is different from that of other processes because tasks can
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* access I/O; this is not allowed to less-privileged processes
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*/
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rp->p_reg.pc = (reg_t) ip->initial_pc;
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rp->p_reg.psw = (iskernelp(rp)) ? INIT_TASK_PSW : INIT_PSW;
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/* Initialize the server stack pointer. Take it down one word
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* to give crtso.s something to use as "argc".
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*/
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if (isusern(proc_nr(rp))) { /* user-space process? */
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rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
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rp->p_memmap[S].mem_len) << CLICK_SHIFT;
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rp->p_reg.sp -= sizeof(reg_t);
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}
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/* Set ready. The HARDWARE task is never ready. */
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if (rp->p_nr != HARDWARE) {
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rp->p_rts_flags = 0; /* runnable if no flags */
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lock_enqueue(rp); /* add to scheduling queues */
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} else {
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rp->p_rts_flags = NO_PRIORITY; /* prevent from running */
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}
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/* Code and data segments must be allocated in protected mode. */
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alloc_segments(rp);
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}
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#if ENABLE_BOOTDEV
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/* Expect an image of the boot device to be loaded into memory as well.
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* The boot device is the last module that is loaded into memory, and,
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* for example, can contain the root FS (useful for embedded systems).
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*/
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hdrindex ++;
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phys_copy(aout + hdrindex * A_MINHDR,vir2phys(&e_hdr),(phys_bytes) A_MINHDR);
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if (e_hdr.a_flags & A_IMG) {
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kinfo.bootdev_base = e_hdr.a_syms;
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kinfo.bootdev_size = e_hdr.a_data;
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}
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#endif
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/* MINIX is now ready. All boot image processes are on the ready queue.
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* Return to the assembly code to start running the current process.
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*/
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bill_ptr = proc_addr(IDLE); /* it has to point somewhere */
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announce(); /* print MINIX startup banner */
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restart();
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}
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/*===========================================================================*
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* announce *
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*===========================================================================*/
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PRIVATE void announce(void)
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{
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/* Display the MINIX startup banner. */
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kprintf("\nMINIX %s.%s. "
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"Copyright 2006, Vrije Universiteit, Amsterdam, The Netherlands\n",
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OS_RELEASE, OS_VERSION);
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#if (CHIP == INTEL)
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/* Real mode, or 16/32-bit protected mode? */
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kprintf("Executing in %s mode.\n\n",
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machine.prot ? "32-bit protected" : "real");
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#endif
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}
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/*===========================================================================*
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* prepare_shutdown *
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*===========================================================================*/
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PUBLIC void prepare_shutdown(how)
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int how;
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{
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/* This function prepares to shutdown MINIX. */
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static timer_t shutdown_timer;
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register struct proc *rp;
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message m;
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/* Send a signal to all system processes that are still alive to inform
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* them that the MINIX kernel is shutting down. A proper shutdown sequence
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* should be implemented by a user-space server. This mechanism is useful
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* as a backup in case of system panics, so that system processes can still
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* run their shutdown code, e.g, to synchronize the FS or to let the TTY
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* switch to the first console.
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*/
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#if DEAD_CODE
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kprintf("Sending SIGKSTOP to system processes ...\n");
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for (rp=BEG_PROC_ADDR; rp<END_PROC_ADDR; rp++) {
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if (!isemptyp(rp) && (priv(rp)->s_flags & SYS_PROC) && !iskernelp(rp))
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send_sig(proc_nr(rp), SIGKSTOP);
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}
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#endif
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/* Continue after 1 second, to give processes a chance to get scheduled to
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* do shutdown work. Set a watchog timer to call shutdown(). The timer
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* argument passes the shutdown status.
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*/
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kprintf("MINIX will now be shut down ...\n");
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tmr_arg(&shutdown_timer)->ta_int = how;
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set_timer(&shutdown_timer, get_uptime() + HZ, shutdown);
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}
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/*===========================================================================*
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* shutdown *
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*===========================================================================*/
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PRIVATE void shutdown(tp)
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timer_t *tp;
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{
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/* This function is called from prepare_shutdown or stop_sequence to bring
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* down MINIX. How to shutdown is in the argument: RBT_HALT (return to the
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* monitor), RBT_MONITOR (execute given code), RBT_RESET (hard reset).
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*/
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int how = tmr_arg(tp)->ta_int;
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u16_t magic;
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/* Now mask all interrupts, including the clock, and stop the clock. */
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outb(INT_CTLMASK, ~0);
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clock_stop();
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if (mon_return && how != RBT_RESET) {
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/* Reinitialize the interrupt controllers to the BIOS defaults. */
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intr_init(0);
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outb(INT_CTLMASK, 0);
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outb(INT2_CTLMASK, 0);
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/* Return to the boot monitor. Set the program if not already done. */
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if (how != RBT_MONITOR) phys_copy(vir2phys(""), kinfo.params_base, 1);
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level0(monitor);
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}
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/* Reset the system by jumping to the reset address (real mode), or by
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* forcing a processor shutdown (protected mode). First stop the BIOS
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* memory test by setting a soft reset flag.
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*/
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magic = STOP_MEM_CHECK;
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phys_copy(vir2phys(&magic), SOFT_RESET_FLAG_ADDR, SOFT_RESET_FLAG_SIZE);
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level0(reset);
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}
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