xv6-cs450/main.c
rsc 943fd378a1 Incorporate new understanding of/with Intel SMP spec.
Dropped cmpxchg in favor of xchg, to match lecture notes.

Use xchg to release lock, for future protection and to
keep gcc from acting clever.
2007-10-01 20:43:15 +00:00

86 lines
2 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)
{
extern char edata[], end[];
// clear BSS
memset(edata, 0, end - edata);
mp_init(); // collect info about this machine
lapic_init(mp_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
bootothers(); // start other processors
// Finish setting up this processor in mpmain.
mpmain();
}
// Bootstrap processor gets here after setting up the hardware.
// Additional processors start here.
static void
mpmain(void)
{
cprintf("cpu%d: mpmain\n", cpu());
idtinit();
if(cpu() != mp_bcpu())
lapic_init(cpu());
setupsegs(0);
xchg(&cpus[cpu()].booted, 1);
cprintf("cpu%d: scheduling\n");
scheduler();
}
static void
bootothers(void)
{
extern uchar _binary_bootother_start[], _binary_bootother_size[];
uchar *code;
struct cpu *c;
char *stack;
// 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.
stack = kalloc(KSTACKSIZE);
*(void**)(code-4) = stack + KSTACKSIZE;
*(void**)(code-8) = mpmain;
lapic_startap(c->apicid, (uint)code);
// Wait for cpu to get through bootstrap.
while(c->booted == 0)
;
}
}