diff options
Diffstat (limited to 'start.c')
| -rw-r--r-- | start.c | 34 |
1 files changed, 16 insertions, 18 deletions
@@ -1,25 +1,19 @@ #include "types.h" +#include "param.h" #include "memlayout.h" #include "riscv.h" #include "defs.h" void main(); -// entry.S uses this as the initial stack. -__attribute__ ((aligned (16))) char stack0[4096]; +// entry.S needs one stack per CPU. +__attribute__ ((aligned (16))) char stack0[4096 * NCPU]; // assembly code in kernelvec for machine-mode timer interrupt. extern void machinevec(); -// scratch area for timer interrupt. -uint64 mscratch0[8]; - -__attribute__ ((aligned (16))) -void -xyzzy() -{ - uartputc('I'); -} +// scratch area for timer interrupt, one per CPU. +uint64 mscratch0[NCPU * 32]; // entry.S jumps here in machine mode on stack0. void @@ -42,15 +36,19 @@ mstart() w_medeleg(0xffff); w_mideleg(0xffff); - // set up to receive timer interrupts in machine mode. - *(uint64*)CLINT_MTIMECMP0 = *(uint64*)CLINT_MTIME + 10000; - mscratch0[4] = CLINT_MTIMECMP0; - mscratch0[5] = 10000000; - w_mscratch((uint64)mscratch0); + // set up to receive timer interrupts in machine mode, + // for pre-emptive switching and (on hart 0) to drive time. + int id = r_mhartid(); + uint64 *scratch = &mscratch0[32 * id]; + *(uint64*)CLINT_MTIMECMP(id) = *(uint64*)CLINT_MTIME + 10000; + scratch[4] = CLINT_MTIMECMP(id); + scratch[5] = 10000000; + w_mscratch((uint64)scratch); w_mtvec((uint64)machinevec); w_mstatus(r_mstatus() | MSTATUS_MIE); w_mie(r_mie() | MIE_MTIE); - // jump to main in supervisor mode. - asm("mret"); + // call main(hartid) in supervisor mode. + asm("csrr a0, mhartid ; \ + mret"); } |