#include <config.h>
#include <riscv.h>
#include <spinlock.h>
#include <types.h>

/* QEMU memory maps a UART device here. */
#define UART_BASE ((volatile char *)0x10000000)

/** Send a single character to the UART device */
void uart_putc(char c) { *UART_BASE = c; }

/** Send a **NULL TERMINATED** string to the UART device */
void uart_puts(const char *s) {
    while (*s) uart_putc(*s++);
}

/**
 * Allocate one stack per CPU (hart).
 * Each stack is 4096 bytes, aligned to 16 bytes for safety and performance.
 * The entry assembly code will calculate the proper stack address for the
 * current hart. For more info, read up on stack pointers and see: entry.S
 */
char stack0[4096 * NCPU] __attribute__((aligned(16)));

/* Keep this here and sync on it until we have synchronized printf */
struct spinlock sl = {0};
volatile int    greeted = 0;

/* This is where entry.S drops us of. All cores land here */
void start() {

    u64 a = r_mhartid();

    acquire(&sl);

    if (!greeted) {
        uart_puts("Hello Neptune!\n");
        greeted = 1;
    }

    uart_puts("Hart number: ");
    uart_putc(a + '0');
    uart_putc('\n');

    release(&sl);

    /* Here we will do a bunch of initialization steps */

    // We should not arrive here, but if we do, hang in a while on wfi.
    while (1) __asm__ volatile("wfi"); // (Wait For Interrupt)
}