diff options
Diffstat (limited to 'src/kernel/trap/handler.cc')
| -rw-r--r-- | src/kernel/trap/handler.cc | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/kernel/trap/handler.cc b/src/kernel/trap/handler.cc new file mode 100644 index 0000000..9cc19d1 --- /dev/null +++ b/src/kernel/trap/handler.cc @@ -0,0 +1,123 @@ +#include "kernel/trap.h" +#include "common/types.h" +#include "drivers/uart.h" + +void panic(const char *s) +{ + Drivers::uart_puts("\n\n!!! KERNEL PANIC !!!\n"); + Drivers::uart_puts(s); + Drivers::uart_puts("\nSystem Halted.\n"); + while (1) + ; +} + +namespace Trap +{ + void init() + { + uint64 stvec_val = (uint64)kernelvec; + asm volatile("csrw stvec, %0" : : "r"(stvec_val)); + + uint64 sstatus; + asm volatile("csrr %0, sstatus" : "=r"(sstatus)); + sstatus &= ~(1L << 1); + asm volatile("csrw sstatus, %0" : : "r"(sstatus)); + + Drivers::uart_puts("[Trap] Initialized stvec to: "); + Drivers::print_hex(stvec_val); + Drivers::uart_puts("\n"); + } + + extern "C" void kerneltrap(struct Trapframe *tf) + { + uint64 scause, stval, sepc; + + asm volatile("csrr %0, scause" : "=r"(scause)); + asm volatile("csrr %0, stval" : "=r"(stval)); + asm volatile("csrr %0, sepc" : "=r"(sepc)); + + if (scause & (1L << 63)) + { + uint64 cause_code = scause & 0x7FFFFFFFFFFFFFFFL; + switch (cause_code) + { + case 1: + Drivers::uart_puts("[IRQ] Software Interrupt\n"); + asm volatile("csrc sip, %0" : : "r"(1 << 1)); + break; + + case 5: + Drivers::uart_puts("[IRQ] Timer Interrupt\n"); + + break; + + case 9: + Drivers::uart_puts("[IRQ] External Interrupt\n"); + break; + + default: + Drivers::uart_puts("[IRQ] Unknown Interrupt: "); + Drivers::print_hex(cause_code); + Drivers::uart_puts("\n"); + break; + } + } + else + { + switch (scause) + { + case 8: + Drivers::uart_puts("[Syscall] ecall for User Mode\n"); + tf->epc += 4; + break; + + case 12: + case 13: + case 15: + Drivers::uart_puts("\n--- PAGE FAULT ---\n"); + Drivers::uart_puts("Cause Code: "); + Drivers::print_hex(scause); + Drivers::uart_puts("\n"); + Drivers::uart_puts("Fault Addr (stval): "); + Drivers::print_hex(stval); + Drivers::uart_puts("\n"); + Drivers::uart_puts("Instruction (sepc): "); + Drivers::print_hex(sepc); + Drivers::uart_puts("\n"); + + if (stval == 0) + { + panic("Null Pointer Dereference!"); + } + else if (stval < 0x80000000) + { + panic("Invalid Low Memory Access!"); + } + else + { + panic("Segmentation Fault (Unmapped Area)"); + } + break; + + case 2: + Drivers::uart_puts("\n--- ILLEGAL INSTRUCTION ---\n"); + Drivers::uart_puts("Instruction (sepc): "); + Drivers::print_hex(sepc); + Drivers::uart_puts("\n"); + panic("CPU encountered an unknown opcode"); + break; + + default: + Drivers::uart_puts("\n--- UNHANDLED EXCEPTION ---\n"); + Drivers::uart_puts("Cause: "); + Drivers::print_hex(scause); + Drivers::uart_puts("\n"); + Drivers::uart_puts("sepc: "); + Drivers::print_hex(sepc); + Drivers::uart_puts("\n"); + panic("System Halt"); + break; + } + } + } +}
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