48602fcfae
- marks code path that should be unreachable (never executed) - if hit, panics and reports the problem - the end of main() marked as such. The SMP changes need some magic with stack switching before the AP can be started as they need to run on the boot stack before figuring out what is their own stack. As main() uses the boot stack to, we need to switch to to the stack of BSP before executing the last part of main() which needs to be in a separate function so we can jump to it. Therefore restart() won't be the last call in main() which may be confusing. The macro can/should be used in other such places too.
264 lines
9.4 KiB
C
Executable file
264 lines
9.4 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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#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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#include "debug.h"
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/* Prototype declarations for PRIVATE functions. */
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FORWARD _PROTOTYPE( void announce, (void));
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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, j, 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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/* Architecture-dependent initialization. */
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arch_init();
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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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#if DEBUG_SCHED_CHECK
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rp->p_magic = PMAGIC;
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#endif
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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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}
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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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/* Warn about violations of the boot image table order consistency. */
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if (priv_id(rp) != s_nr_to_id(ip->proc_nr))
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kprintf("Warning: boot image table has wrong process order\n");
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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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for (j = 0; j < NR_SYS_PROCS && j < BITCHUNK_BITS; j++)
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if (ip->ipc_to & (1 << j))
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set_sendto_bit(rp, j); /* 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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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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/* Architecture-specific way to find out aout header of this
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* boot process.
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*/
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arch_get_aout_headers(hdrindex, &e_hdr);
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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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/* scheduling functions depend on proc_ptr pointing somewhere. */
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if(!proc_ptr) proc_ptr = rp;
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/* If this process has its own page table, VM will set the
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* PT up and manage it. VM will signal the kernel when it has
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* done this; until then, don't let it run.
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*/
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if(priv(rp)->s_flags & PROC_FULLVM)
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RTS_SET(rp, VMINHIBIT);
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/* Set ready. The HARDWARE task is never ready. */
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if (rp->p_nr == HARDWARE) RTS_SET(rp, NO_PRIORITY);
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RTS_UNSET(rp, SLOT_FREE); /* remove SLOT_FREE and schedule */
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alloc_segments(rp);
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}
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#if SPROFILE
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sprofiling = 0; /* we're not profiling until instructed to */
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#endif /* SPROFILE */
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cprof_procs_no = 0; /* init nr of hash table slots used */
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vm_running = 0;
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krandom.random_sources = RANDOM_SOURCES;
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krandom.random_elements = RANDOM_ELEMENTS;
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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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/* Warnings for sanity checks that take time. These warnings are printed
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* so it's a clear warning no full release should be done with them
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* enabled.
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*/
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#if DEBUG_SCHED_CHECK
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FIXME("DEBUG_SCHED_CHECK enabled");
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#endif
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#if DEBUG_VMASSERT
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FIXME("DEBUG_VMASSERT enabled");
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#endif
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#if DEBUG_PROC_CHECK
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FIXME("PROC check enabled");
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#endif
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restart();
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NOT_REACHABLE();
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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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#ifdef _SVN_REVISION
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"(" _SVN_REVISION ")\n"
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#endif
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"Copyright 2009, Vrije Universiteit, Amsterdam, The Netherlands\n",
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OS_RELEASE, OS_VERSION);
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kprintf("MINIX is open source software, see http://www.minix3.org\n");
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FIXME("pm, vfs, etc own page table");
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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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/* 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() + system_hz, minix_shutdown);
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}
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/*===========================================================================*
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* shutdown *
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*===========================================================================*/
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PUBLIC void minix_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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intr_init(INTS_ORIG);
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clock_stop();
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arch_shutdown(tp ? tmr_arg(tp)->ta_int : RBT_PANIC);
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}
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