/* main.c — the arch-agnostic OS entry point.
 *
 * By the time kmain() runs, the arch's asm entry has: set up a stack,
 * cleared .bss (or the arch stub did), and jumped here. Everything below
 * is identical C for x86, RISC-V and ARM — that's the whole point of the
 * exercise: same core, three ISAs. */
#include "arch.h"
#include "console.h"

void kmain(void)
{
	arch_early_init();
	arch_set_trap_vector();

	puts("\n");
	puts("========================================\n");
	puts("  minos — minimal multi-arch kernel\n");
	puts("  arch: ");
	puts(arch_name());
	puts("\n");
	puts("  cpu mode: ");
	puts(arch_cpu_mode());
	puts("  (most privileged; no user mode yet)\n");
	puts("  M1: booted, UART up, trap vector set\n");
	puts("========================================\n");
	puts("hello from kmain()\n");

	/* Interactive echo: proves UART input (RX) works. Type on the serial
	 * console and minos echoes each key back. This is the seed of a real
	 * console — M3 will turn it into a command interface. */
	puts("\nType something (keys are echoed back):\n> ");
	drain_rx(); /* drop any bytes already sitting in the RX FIFO */
	for (;;) {
		char c = getc();
		if (c == '\r' || c == '\n') {
			puts("\n> ");      /* newline + fresh prompt */
			continue;
		}
		if (c == 0x7f || c == 0x08) { /* DEL / backspace */
			puts("\b \b");
			continue;
		}
		putc(c);                   /* echo the key */
	}
}