#include "kernel.h" #include "common.h" extern char __bss[], __bss_end[], __stack_top[]; struct sbiret sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long fid, long eid) { register long a0 __asm__("a0") = arg0; register long a1 __asm__("a1") = arg1; register long a2 __asm__("a2") = arg2; register long a3 __asm__("a3") = arg3; register long a4 __asm__("a4") = arg4; register long a5 __asm__("a5") = arg5; register long a6 __asm__("a6") = fid; register long a7 __asm__("a7") = eid; __asm__ __volatile__("ecall" : "=r"(a0), "=r"(a1) : "r"(a0), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5), "r"(a6), "r"(a7) : "memory"); return (struct sbiret){.error = a0, .value = a1}; } void putchar(char ch) { sbi_call(ch, 0, 0, 0, 0, 0, 0, 1 /* Console Putchar */); } void kernel_main(void) { printf("\n\nHello %s\n", "RETARD!"); printf("60 + 9 = %d, %x\n", 60 + 9, 0x1234abcd); for (;;) { __asm__ __volatile__("wfi"); } } __attribute__((section(".text.boot"))) __attribute__((naked)) void boot(void) { __asm__ __volatile__( "mv sp, %[stack_top]\n" // Set the stack pointer "j kernel_main\n" // Jump to the kernel main function : : [stack_top] "r" (__stack_top) // Pass the stack top address as %[stack_top] ); }