diff options
Diffstat (limited to 'PL0_test.c')
-rw-r--r-- | PL0_test.c | 18 |
1 files changed, 17 insertions, 1 deletions
@@ -1,9 +1,25 @@ #include "uart.h" +#include "psr.h" void PL0_main(void) { - uart_puts("hello PL0!\n\r"); + uart_puts("hello PL0! Switching to user mode!\n\r"); + asm("cps #0b10000\n\r" + "isb" ::: "memory"); + + // if all went correct, Success! gets printed + uart_puts("Success!\n\r"); + + // if we're indeed i PL0, we should crash now, when trying to access + // memory we're not allowed to + char first_kernel_byte[2]; + + first_kernel_byte[0] = *(char*) ((uint32_t) 0x8000); + first_kernel_byte[1] = '\0'; + + uart_puts(first_kernel_byte); + while (1) { char c; |