root/kernel/main.c

/* */

DEFINITIONS

1. start_kernel
2. stop_kernel
3. cpu_idle

   1 /*
   2  * fiwix/kernel/main.c
   3  *
   4  * Copyright 2018-2021, Jordi Sanfeliu. All rights reserved.
   5  * Distributed under the terms of the Fiwix License.
   6  */
   7 
   8 #include <fiwix/asm.h>
   9 #include <fiwix/kernel.h>
  10 #include <fiwix/limits.h>
  11 #include <fiwix/fs.h>
  12 #include <fiwix/system.h>
  13 #include <fiwix/version.h>
  14 #include <fiwix/utsname.h>
  15 #include <fiwix/stdio.h>
  16 #include <fiwix/string.h>
  17 #include <fiwix/video.h>
  18 #include <fiwix/console.h>
  19 #include <fiwix/pic.h>
  20 #include <fiwix/segments.h>
  21 #include <fiwix/devices.h>
  22 #include <fiwix/cpu.h>
  23 #include <fiwix/timer.h>
  24 #include <fiwix/sleep.h>
  25 #include <fiwix/keyboard.h>
  26 #include <fiwix/sched.h>
  27 #include <fiwix/mm.h>
  28 
  29 unsigned int _last_data_addr;
  30 int _memsize;
  31 int _extmemsize;
  32 int _rootdev;
  33 int _noramdisk;
  34 int _ramdisksize;
  35 char _rootfstype[10];
  36 char _rootdevname[DEVNAME_MAX + 1];
  37 char _initrd[DEVNAME_MAX + 1];
  38 int _syscondev;
  39 char *init_args;
  40 
  41 char cmdline[NAME_MAX + 1];
  42 
  43 struct new_utsname sys_utsname = {
  44         UTS_SYSNAME,
  45         UTS_NODENAME,
  46         UTS_RELEASE,
  47         UTS_VERSION,
  48         "",
  49         UTS_DOMAINNAME,
  50 };
  51 
  52 struct kernel_stat kstat;
  53 
  54 void start_kernel(unsigned long magic, unsigned long info, unsigned int stack)
  55 {
  56         struct proc *init;
  57 
  58         _last_data_addr = stack - KERNEL_BASE_ADDR;
  59         memset_b(&kstat, NULL, sizeof(kstat));
  60 
  61         /* default kernel values */
  62         strcpy(_rootfstype, "ext2");            /* filesystem is ext2 */
  63         _syscondev = MKDEV(VCONSOLES_MAJOR, 0); /* console is /dev/tty0 */
  64 
  65         pic_init();
  66         idt_init();
  67         dev_init();
  68         tty_init();
  69 
  70         printk("                                Welcome to %s\n", UTS_SYSNAME);
  71         printk("                     Copyright (c) 2018-2021, Jordi Sanfeliu\n");
  72         printk("\n");
  73         printk("                      kernel v%s for i386 architecture\n", UTS_RELEASE);
  74         printk("               (GCC %s, built on %s)\n", __VERSION__, UTS_VERSION);
  75         printk("\n");
  76         printk("DEVICE    ADDRESS         IRQ   COMMENT\n");
  77         printk("--------------------------------------------------------------------------------\n");
  78 
  79         cpu_init();
  80         multiboot(magic, info);
  81         mem_init();
  82         video_init();
  83         console_init();
  84         timer_init();
  85         keyboard_init();
  86         proc_init();
  87 
  88         /*
  89          * IDLE is now the current process (created manually as PID 0),
  90          * it won't be placed in the running queue.
  91          */
  92         current = get_proc_free();
  93         proc_slot_init(current);
  94         set_tss(current);
  95         load_tr(TSS);
  96         current->tss.cr3 = (unsigned int)kpage_dir;
  97         current->flags |= PF_KPROC;
  98         sprintk(current->argv0, "%s", "idle");
  99 
 100         /* PID 1 is for the INIT process */
 101         init = get_proc_free();
 102         proc_slot_init(init);
 103         init->pid = get_unused_pid();
 104 
 105         /* PID 2 is for the kswapd process */
 106         kernel_process("kswapd", kswapd);
 107 
 108         /* kswapd will take over the rest of the kernel initialization */
 109         need_resched = 1;
 110 
 111         STI();          /* let's rock! */
 112         cpu_idle();
 113 }
 114 
 115 void stop_kernel(void)
 116 {
 117         struct proc *p;
 118         int n;
 119 
 120         /* stop and disable all interrupts! */
 121         CLI();
 122         for(n = 0; n < NR_IRQS; n++) {
 123                 disable_irq(n);
 124         }
 125 
 126         printk("\n");
 127         printk("**    Safe to Power Off    **\n");
 128         printk("            -or-\n");
 129         printk("** Press Any Key to Reboot **\n");
 130         any_key_to_reboot = 1;
 131 
 132         /* put all processes to sleep and reset all pending signals */
 133         FOR_EACH_PROCESS_RUNNING(p) {
 134                 not_runnable(p, PROC_SLEEPING);
 135                 p->sigpending = 0;
 136                 p = p->next_run;
 137         }
 138 
 139         /* enable keyboard only */
 140         STI();
 141         enable_irq(KEYBOARD_IRQ);
 142 
 143         /* switch to IDLE process */
 144         if(current) {
 145                 do_sched();
 146         }
 147 
 148         cpu_idle();
 149 }
 150 
 151 void cpu_idle()
 152 {
 153         for(;;) {
 154                 if(need_resched) {
 155                         do_sched();
 156                 }
 157                 HLT();
 158         }
 159 }

/* */