minix/kernel/start.c
2011-07-31 16:22:43 +02:00

165 lines
4.5 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 USE_WATCHDOG
#include "watchdog.h"
#endif
/*===========================================================================*
* cstart *
*===========================================================================*/
PUBLIC void cstart(
u16_t cs, /* kernel code segment */
u16_t ds, /* kernel data segment */
u16_t mds, /* monitor data segment */
u16_t parmoff, /* boot parameters offset */
u16_t parmsize /* boot parameters 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));
/* determine verbosity */
if ((value = env_get(VERBOSEBOOTVARNAME)))
verboseboot = atoi(value);
DEBUGEXTRA(("cstart\n"));
/* 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(env_get("processor"));
/* XT, AT or MCA bus? */
value = env_get("bus");
if (value == NULL || 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 = env_get("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 = env_get("hz");
if(value)
system_hz = atoi(value);
if(!value || system_hz < 2 || system_hz > 50000) /* sanity check */
system_hz = DEFAULT_HZ;
/* Intitialize serial debugging */
value = env_get(SERVARNAME);
if(value && atoi(value) == 0) {
do_serial_debug=1;
value = env_get(SERBAUDVARNAME);
if (value) serial_debug_baud = atoi(value);
}
#ifdef USE_APIC
value = env_get("no_apic");
if(value)
config_no_apic = atoi(value);
else
config_no_apic = 1;
value = env_get("apic_timer_x");
if(value)
config_apic_timer_x = atoi(value);
else
config_apic_timer_x = 1;
#endif
#ifdef USE_WATCHDOG
value = env_get("watchdog");
if (value)
watchdog_enabled = atoi(value);
#endif
#ifdef CONFIG_SMP
if (config_no_apic)
config_no_smp = 1;
value = env_get("no_smp");
if(value)
config_no_smp = atoi(value);
else
config_no_smp = 0;
#endif
/* Return to assembler code to switch to protected mode (if 286),
* reload selectors and call main().
*/
DEBUGEXTRA(("intr_init(%d, 0)\n", INTS_MINIX));
intr_init(INTS_MINIX, 0);
}
/*===========================================================================*
* get_value *
*===========================================================================*/
PUBLIC char *get_value(
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(NULL);
}
/*===========================================================================*
* env_get *
*===========================================================================*/
PUBLIC char *env_get(const char *name)
{
return get_value(params_buffer, name);
}