#include "calls.h"

extern char __bss[], __bss_end[], __stack_top[];

__attribute__((section(".text.boot")))
__attribute__((naked))
void boot(void) {
    __asm__ __volatile__ (
        "mv sp, %[stack_top]\n"
        "j kernel_main\n"
        :
        : [stack_top] "r" (__stack_top)
    );
}

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 (sbiret){ .error = a0, .value = a1 };
}

void putchar(char ch) {
    sbi_call(ch, 0, 0, 0, 0, 0, 0, 0x1 /* Console Putchar */);
}

int getchar(void) {
    sbiret r = sbi_call(0, 0, 0, 0, 0, 0, 0, 0x2);
    return r.error;
}

void sbi_shutdown(void) {
  sbi_call(0, 0, 0, 0, 0, 0, 0, 0x8);
}

sbiret sbi_get_impl_id(void) {
  return sbi_call(0, 0, 0, 0, 0, 0, 0x1, 0x10);
}

sbiret sbi_get_spec_version(void) {
  return sbi_call(0, 0, 0, 0, 0, 0, 0x2, 0x10);
}

sbiret sbi_hart_stop(void) {
  return sbi_call(0, 0, 0, 0, 0, 0, 0x1, 0x48534D);
}

sbiret sbi_hart_get_status(unsigned long hartid) {
  return sbi_call(hartid, 0, 0, 0, 0, 0, 0x2, 0x48534D);
}