ref: f40225e86cf4b92cab975d9121ff06ed5cfe9d91
dir: /sys/src/9/pc/main.c/
#include "u.h"
#include "tos.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/pci.h"
#include "ureg.h"
#include "pool.h"
#include "rebootcode.i"
Mach *m;
Conf conf;
int delaylink;
int idle_spin;
extern void (*i8237alloc)(void);
extern void bootscreeninit(void);
extern void multibootdebug(void);
void
main(void)
{
mach0init();
bootargsinit();
trapinit0();
ioinit();
i8250console();
quotefmtinstall();
screeninit();
print("\nPlan 9\n");
cpuidentify();
meminit0();
archinit();
if(arch->clockinit)
arch->clockinit();
meminit();
ramdiskinit();
confinit();
xinit();
if(i8237alloc != nil)
i8237alloc();
pcicfginit();
bootscreeninit();
trapinit();
printinit();
cpuidprint();
mmuinit();
if(arch->intrinit) /* launches other processors on an mp */
arch->intrinit();
timersinit();
mathinit();
if(arch->clockenable)
arch->clockenable();
procinit0();
initseg();
if(delaylink){
bootlinks();
}else
links();
chandevreset();
pageinit();
userinit();
schedinit();
}
void
mach0init(void)
{
conf.nmach = 1;
MACHP(0) = (Mach*)CPU0MACH;
m->pdb = (ulong*)CPU0PDB;
m->gdt = (Segdesc*)CPU0GDT;
machinit();
active.machs[0] = 1;
active.exiting = 0;
}
void
machinit(void)
{
int machno;
ulong *pdb;
Segdesc *gdt;
machno = m->machno;
pdb = m->pdb;
gdt = m->gdt;
memset(m, 0, sizeof(Mach));
m->machno = machno;
m->pdb = pdb;
m->gdt = gdt;
m->perf.period = 1;
/*
* For polled uart output at boot, need
* a default delay constant. 100000 should
* be enough for a while. Cpuidentify will
* calculate the real value later.
*/
m->loopconst = 100000;
}
void
init0(void)
{
char buf[2*KNAMELEN], **sp;
chandevinit();
if(!waserror()){
snprint(buf, sizeof(buf), "%s %s", arch->id, conffile);
ksetenv("terminal", buf, 0);
ksetenv("cputype", "386", 0);
if(cpuserver)
ksetenv("service", "cpu", 0);
else
ksetenv("service", "terminal", 0);
setconfenv();
poperror();
}
kproc("alarm", alarmkproc, 0);
sp = (char**)(USTKTOP - sizeof(Tos) - 8 - sizeof(sp[0])*4);
sp[3] = sp[2] = nil;
strcpy(sp[1] = (char*)&sp[4], "boot");
sp[0] = nil;
touser(sp);
}
void
confinit(void)
{
char *p;
int i, userpcnt;
ulong kpages;
if(p = getconf("service")){
if(strcmp(p, "cpu") == 0)
cpuserver = 1;
else if(strcmp(p,"terminal") == 0)
cpuserver = 0;
}
if(p = getconf("*kernelpercent"))
userpcnt = 100 - strtol(p, 0, 0);
else
userpcnt = 0;
conf.npage = 0;
for(i=0; i<nelem(conf.mem); i++)
conf.npage += conf.mem[i].npage;
conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
if(cpuserver)
conf.nproc *= 3;
if(conf.nproc > 4000)
conf.nproc = 4000;
conf.nimage = 200;
conf.nswap = conf.nproc*80;
conf.nswppo = 4096;
if(cpuserver) {
if(userpcnt < 10)
userpcnt = 70;
kpages = conf.npage - (conf.npage*userpcnt)/100;
conf.nimage = conf.nproc;
/*
* Hack for the big boys. Only good while physmem < 4GB.
* Give the kernel fixed max + enough to allocate the
* page pool.
* This is an overestimate as conf.upages < conf.npages.
* The patch of nimage is a band-aid, scanning the whole
* page list in imagereclaim just takes too long.
*/
if(getconf("*imagemaxmb") == 0)
if(kpages > (64*MB + conf.npage*sizeof(Page))/BY2PG){
kpages = (64*MB + conf.npage*sizeof(Page))/BY2PG;
kpages += (conf.nproc*KSTACK)/BY2PG;
}
} else {
if(userpcnt < 10) {
if(conf.npage*BY2PG < 16*MB)
userpcnt = 50;
else
userpcnt = 60;
}
kpages = conf.npage - (conf.npage*userpcnt)/100;
/*
* Make sure terminals with low memory get at least
* 4MB on the first Image chunk allocation.
*/
if(conf.npage*BY2PG < 16*MB)
imagmem->minarena = 4*MB;
}
/*
* can't go past the end of virtual memory
* (ulong)-KZERO is 2^32 - KZERO
*/
if(kpages > ((ulong)-KZERO)/BY2PG)
kpages = ((ulong)-KZERO)/BY2PG;
conf.upages = conf.npage - kpages;
conf.ialloc = (kpages/2)*BY2PG;
/*
* Guess how much is taken by the large permanent
* datastructures. Mntcache and Mntrpc are not accounted for.
*/
kpages *= BY2PG;
kpages -= conf.upages*sizeof(Page)
+ conf.nproc*sizeof(Proc*)
+ conf.nimage*sizeof(Image)
+ conf.nswap
+ conf.nswppo*sizeof(Page*);
mainmem->maxsize = kpages;
/*
* the dynamic allocation will balance the load properly,
* hopefully. be careful with 32-bit overflow.
*/
imagmem->maxsize = kpages - (kpages/10);
if(p = getconf("*imagemaxmb")){
imagmem->maxsize = strtol(p, nil, 0)*MB;
if(imagmem->maxsize > mainmem->maxsize)
imagmem->maxsize = mainmem->maxsize;
}
}
void
procsetup(Proc *p)
{
fpuprocsetup(p);
memset(p->gdt, 0, sizeof(p->gdt));
p->nldt = 0;
/* clear debug registers */
memset(p->dr, 0, sizeof(p->dr));
if(m->dr7 != 0){
m->dr7 = 0;
putdr7(0);
}
}
void
procfork(Proc *p)
{
/* inherit user descriptors */
memmove(p->gdt, up->gdt, sizeof(p->gdt));
/* copy local descriptor table */
if(up->ldt != nil && up->nldt > 0){
p->ldt = smalloc(sizeof(Segdesc) * up->nldt);
memmove(p->ldt, up->ldt, sizeof(Segdesc) * up->nldt);
p->nldt = up->nldt;
}
fpuprocfork(p);
}
void
procrestore(Proc *p)
{
if(p->dr[7] != 0){
m->dr7 = p->dr[7];
putdr(p->dr);
}
if(p->vmx != nil)
vmxprocrestore(p);
fpuprocrestore(p);
}
/*
* Save the mach dependent part of the process state.
*/
void
procsave(Proc *p)
{
/* we could just always putdr7(0) but accessing DR7 might be slow in a VM */
if(m->dr7 != 0){
m->dr7 = 0;
putdr7(0);
}
if(p->state == Moribund)
p->dr[7] = 0;
fpuprocsave(p);
/*
* While this processor is in the scheduler, the process could run
* on another processor and exit, returning the page tables to
* the free list where they could be reallocated and overwritten.
* When this processor eventually has to get an entry from the
* trashed page tables it will crash.
*
* If there's only one processor, this can't happen.
* You might think it would be a win not to do this in that case,
* especially on VMware, but it turns out not to matter.
*/
mmuflushtlb(PADDR(m->pdb));
}
static void
rebootjump(uintptr entry, uintptr code, ulong size)
{
void (*f)(uintptr, uintptr, ulong);
ulong *pdb;
splhi();
arch->introff();
/*
* Modify the machine page table to directly map the low 4MB of memory
* This allows the reboot code to turn off the page mapping
*/
pdb = m->pdb;
pdb[PDX(0)] = pdb[PDX(KZERO)];
mmuflushtlb(PADDR(pdb));
/* setup reboot trampoline function */
f = (void*)REBOOTADDR;
memmove(f, rebootcode, sizeof(rebootcode));
/* off we go - never to return */
coherence();
(*f)(entry, code, size);
for(;;);
}
void
exit(int)
{
cpushutdown();
if(m->machno)
rebootjump(0, 0, 0);
arch->reset();
}
void
reboot(void *entry, void *code, ulong size)
{
writeconf();
vmxshutdown();
/*
* the boot processor is cpu0. execute this function on it
* so that the new kernel has the same cpu0. this only matters
* because the hardware has a notion of which processor was the
* boot processor and we look at it at start up.
*/
if (m->machno != 0) {
procwired(up, 0);
sched();
}
cpushutdown();
delay(1000);
splhi();
/* turn off buffered serial console */
serialoq = nil;
/* shutdown devices */
chandevshutdown();
/* disable pci devices */
pcireset();
rebootjump((ulong)entry & ~0xF0000000UL, PADDR(code), size);
}