diff options
| -rw-r--r-- | trap.c | 24 |
1 files changed, 13 insertions, 11 deletions
@@ -21,6 +21,19 @@ trapinit(void) // send interrupts and exceptions to kerneltrap(). w_stvec((uint64)kerneltrap); + // set up the riscv Platform Level Interrupt Controller + // to send uart interrupts to hart 0 S-Mode. + + // qemu makes UART0 be interrupt number 10. + int irq = 10; + // set uart's priority to be non-zero (otherwise disabled). + *(uint*)(0x0c000000L + irq*4) = 1; + // set uart's enable bit for hart 0 S-mode. + *(uint*)0x0c002080 = (1 << irq); + + // set hart 0 S-mode priority threshold to 0. + *(uint*)0x0c201000 = 0; + initlock(&tickslock, "time"); } @@ -43,17 +56,6 @@ usertrap(void) // save user program counter. p->tf->epc = r_sepc(); - // PLIC setup - // qemu makes UART0 be interrupt number 10. - int irq = 10; - // set uart's priority to be non-zero (otherwise disabled). - *(uint*)(0x0c000000L + irq*4) = 1; - // set uart's enable bit for hart 0 s-mode. - *(uint*)0x0c002080 = (1 << irq); - - // hart 0 S-mode priority threshold. - *(uint*)0x0c201000 = 0; - intr_on(); if(r_scause() == 8){ |