77 lines
1.8 KiB
C
77 lines
1.8 KiB
C
|
// TODO: CHECK/REPLACE/UPDATE OLD CODE (this file is based on xv6)
|
||
|
|
#include "types.h"
|
||
|
|
#include "param.h"
|
||
|
|
#include "memlayout.h"
|
||
|
|
#include "riscv.h"
|
||
|
|
#include "defs.h"
|
||
|
|
#include "sched.h"
|
||
|
|
|
||
|
|
void main();
|
||
|
|
void timerinit();
|
||
|
|
|
||
|
|
// entry.S needs one stack per CPU.
|
||
|
|
/*TODO __attribute__ ((aligned (16))) char stack0[4096 * NCPU]; */
|
||
|
|
uint64 stack0[512*SCHED_CORE_MAX];
|
||
|
|
|
||
|
|
// entry.S jumps here in machine mode on stack0.
|
||
|
|
void
|
||
|
|
start()
|
||
|
|
{
|
||
|
|
//consputc(65);
|
||
|
|
// set M Previous Privilege mode to Supervisor, for mret.
|
||
|
|
unsigned long x = r_mstatus();
|
||
|
|
x &= ~MSTATUS_MPP_MASK;
|
||
|
|
x |= MSTATUS_MPP_S;
|
||
|
|
w_mstatus(x);
|
||
|
|
|
||
|
|
// set M Exception Program Counter to main, for mret.
|
||
|
|
// requires gcc -mcmodel=medany
|
||
|
|
w_mepc((uint64)(&main));
|
||
|
|
|
||
|
|
// disable paging for now.
|
||
|
|
w_satp(0);
|
||
|
|
|
||
|
|
// delegate all interrupts and exceptions to supervisor mode.
|
||
|
|
w_medeleg(0xffff);
|
||
|
|
w_mideleg(0xffff);
|
||
|
|
w_sie(r_sie() | SIE_SEIE | SIE_STIE | SIE_SSIE);
|
||
|
|
|
||
|
|
// configure Physical Memory Protection to give supervisor mode
|
||
|
|
// access to all of physical memory.
|
||
|
|
w_pmpaddr0(0x3fffffffffffffull);
|
||
|
|
w_pmpcfg0(0xf);
|
||
|
|
|
||
|
|
// ask for clock interrupts.
|
||
|
|
timerinit();
|
||
|
|
|
||
|
|
// keep each CPU's hartid in its tp register, for SCHED_CORE_THISNUMBER_NOINTERRUPTS().
|
||
|
|
int _id = r_mhartid();
|
||
|
|
sched_cputhreadpointer_set(_id);
|
||
|
|
|
||
|
|
// switch to supervisor mode and jump to main().
|
||
|
|
#ifdef _ZCC
|
||
|
|
__asm {
|
||
|
|
mret
|
||
|
|
};
|
||
|
|
#else
|
||
|
|
asm volatile("mret");
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
// ask each hart to generate timer interrupts.
|
||
|
|
void
|
||
|
|
timerinit()
|
||
|
|
{
|
||
|
|
// enable supervisor-mode timer interrupts.
|
||
|
|
w_mie(r_mie() | MIE_STIE);
|
||
|
|
|
||
|
|
// enable the sstc extension (i.e. stimecmp).
|
||
|
|
w_menvcfg(r_menvcfg() | (1L << 63));
|
||
|
|
|
||
|
|
// allow supervisor to use stimecmp and time.
|
||
|
|
w_mcounteren(r_mcounteren() | 2);
|
||
|
|
|
||
|
|
// ask for the very first timer interrupt.
|
||
|
|
w_stimecmp(r_time() + 1000000);
|
||
|
|
}
|