xv6/main.c

95 lines
2.3 KiB
C

#include "types.h"
#include "defs.h"
#include "param.h"
#include "mmu.h"
#include "proc.h"
#include "x86.h"
static void bootothers(void);
static void mpmain(void) __attribute__((noreturn));
// Bootstrap processor starts running C code here.
int
main(void)
{
int bcpu, i;
extern char edata[], end[];
// clear BSS
memset(edata, 0, end - edata);
// pushcli() every processor during bootstrap.
for(i=0; i<NCPU; i++)
cpus[i].ncli = 1; // no interrupts during bootstrap
mp_init(); // collect info about this machine
bcpu = mp_bcpu();
lapic_init(bcpu);
cprintf("\ncpu%d: starting xv6\n\n", cpu());
pinit(); // process table
binit(); // buffer cache
pic_init(); // interrupt controller
ioapic_init(); // another interrupt controller
kinit(); // physical memory allocator
tvinit(); // trap vectors
fileinit(); // file table
iinit(); // inode cache
console_init(); // I/O devices & their interrupts
ide_init(); // disk
if(!ismp)
timer_init(); // uniprocessor timer
userinit(); // first user process
// Allocate scheduler stacks and boot the other CPUs.
for(i=0; i<ncpu; i++)
cpus[i].stack = kalloc(KSTACKSIZE);
bootothers();
// Switch to our scheduler stack and continue with mpmain.
asm volatile("movl %0, %%esp" : : "r" (cpus[bcpu].stack+KSTACKSIZE));
mpmain();
}
// Additional processors start here.
static void
mpmain(void)
{
cprintf("cpu%d: mpmain\n", cpu());
idtinit();
if(cpu() != mp_bcpu())
lapic_init(cpu());
setupsegs(0);
cpuid(0, 0, 0, 0, 0); // memory barrier
cpus[cpu()].booted = 1;
popcli();
scheduler();
}
static void
bootothers(void)
{
extern uchar _binary_bootother_start[], _binary_bootother_size[];
uchar *code;
struct cpu *c;
// Write bootstrap code to unused memory at 0x7000.
code = (uchar*)0x7000;
memmove(code, _binary_bootother_start, (uint)_binary_bootother_size);
for(c = cpus; c < cpus+ncpu; c++){
if(c == cpus+cpu()) // We've started already.
continue;
// Fill in %esp, %eip and start code on cpu.
*(void**)(code-4) = c->stack + KSTACKSIZE;
*(void**)(code-8) = mpmain;
lapic_startap(c->apicid, (uint)code);
// Wait for cpu to get through bootstrap.
while(c->booted == 0)
;
}
}