minix/kernel/start.c
2010-01-26 10:59:01 +00:00

125 lines
3.9 KiB
C

/* First C file used by the kernel. */
#include "kernel.h"
#include "proc.h"
#include <stdlib.h>
#include <string.h>
#include "proto.h"
#ifdef CONFIG_WATCHDOG
#include "watchdog.h"
#endif
FORWARD _PROTOTYPE( char *get_value, (_CONST char *params, _CONST char *key));
/*===========================================================================*
* cstart *
*===========================================================================*/
PUBLIC void cstart(cs, ds, mds, parmoff, parmsize)
U16_t cs, ds; /* kernel code and data segment */
U16_t mds; /* monitor data segment */
U16_t parmoff, parmsize; /* boot parameters offset and length */
{
/* Perform system initializations prior to calling main(). Most settings are
* determined with help of the environment strings passed by MINIX' loader.
*/
register char *value; /* value in key=value pair */
extern int etext, end;
int h;
/* Record where the kernel and the monitor are. */
kinfo.code_base = seg2phys(cs);
kinfo.code_size = (phys_bytes) &etext; /* size of code segment */
kinfo.data_base = seg2phys(ds);
kinfo.data_size = (phys_bytes) &end; /* size of data segment */
/* protection initialization */
prot_init();
/* Copy the boot parameters to the local buffer. */
arch_get_params(params_buffer, sizeof(params_buffer));
/* Record miscellaneous information for user-space servers. */
kinfo.nr_procs = NR_PROCS;
kinfo.nr_tasks = NR_TASKS;
strncpy(kinfo.release, OS_RELEASE, sizeof(kinfo.release));
kinfo.release[sizeof(kinfo.release)-1] = '\0';
strncpy(kinfo.version, OS_VERSION, sizeof(kinfo.version));
kinfo.version[sizeof(kinfo.version)-1] = '\0';
kinfo.proc_addr = (vir_bytes) proc;
/* Load average data initialization. */
kloadinfo.proc_last_slot = 0;
for(h = 0; h < _LOAD_HISTORY; h++)
kloadinfo.proc_load_history[h] = 0;
/* Processor? Decide if mode is protected for older machines. */
machine.processor=atoi(get_value(params_buffer, "processor"));
/* XT, AT or MCA bus? */
value = get_value(params_buffer, "bus");
if (value == NIL_PTR || strcmp(value, "at") == 0) {
machine.pc_at = TRUE; /* PC-AT compatible hardware */
} else if (strcmp(value, "mca") == 0) {
machine.pc_at = machine.ps_mca = TRUE; /* PS/2 with micro channel */
}
/* Type of VDU: */
value = get_value(params_buffer, "video"); /* EGA or VGA video unit */
if (strcmp(value, "ega") == 0) machine.vdu_ega = TRUE;
if (strcmp(value, "vga") == 0) machine.vdu_vga = machine.vdu_ega = TRUE;
/* Get clock tick frequency. */
value = get_value(params_buffer, "hz");
if(value)
system_hz = atoi(value);
if(!value || system_hz < 2 || system_hz > 50000) /* sanity check */
system_hz = DEFAULT_HZ;
value = get_value(params_buffer, SERVARNAME);
if(value && atoi(value) == 0)
do_serial_debug=1;
#ifdef CONFIG_APIC
value = get_value(params_buffer, "no_apic");
if(value)
config_no_apic = atoi(value);
else
config_no_apic = 1;
#endif
#ifdef CONFIG_WATCHDOG
value = get_value(params_buffer, "watchdog");
if (value)
watchdog_enabled = atoi(value);
#endif
/* Return to assembler code to switch to protected mode (if 286),
* reload selectors and call main().
*/
intr_init(INTS_MINIX, 0);
}
/*===========================================================================*
* get_value *
*===========================================================================*/
PRIVATE char *get_value(params, name)
_CONST char *params; /* boot monitor parameters */
_CONST char *name; /* key to look up */
{
/* Get environment value - kernel version of getenv to avoid setting up the
* usual environment array.
*/
register _CONST char *namep;
register char *envp;
for (envp = (char *) params; *envp != 0;) {
for (namep = name; *namep != 0 && *namep == *envp; namep++, envp++)
;
if (*namep == '\0' && *envp == '=') return(envp + 1);
while (*envp++ != 0)
;
}
return(NIL_PTR);
}