/* $NetBSD: boot.c,v 1.2 2025/11/16 22:37:49 jmcneill Exp $ */

/*-
 * Copyright (c) 2025 Jared McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <lib/libsa/stand.h>
#include <lib/libsa/loadfile.h>

#include <powerpc/include/psl.h>
#include <powerpc/include/spr.h>

#include <machine/pio.h>

#include "cache.h"
#include "console.h"
#include "gpio.h"
#include "miniipc.h"
#include "sdmmc.h"
#include "timer.h"

#define PI_INTERRUPT_CAUSE      0x0c003000
#define  RESET_SWITCH_STATE     __BIT(16)

#define HW_BASE                 0x0d800000
#define HW_RESETS               (HW_BASE + 0x194)
#define  RSTBINB                __BIT(0)

static const char * const names[] = {
        "netbsd", "netbsd.gz",
        "onetbsd", "onetbsd.gz",
        "netbsd.old", "onetbsd.old.gz",
};
#define NUMNAMES        __arraycount(names)

static int      exec_netbsd(const char *);

int
main(void)
{
        extern uint8_t edata[], end[];
        int curname;

        memset(&edata, 0, end - edata); /* clear BSS */

        gpio_enable_int(GPIO_EJECT_BTN);
        gpio_ack_int(GPIO_EJECT_BTN);

        console_init();

        gpio_set(GPIO_SLOT_LED);

        if (!miniipc_probe()) {
                panic("MINI IPC not found!");
        }

        sdmmc_init();

        curname = gpio_get_int(GPIO_EJECT_BTN) ? 2 : 0;
        gpio_disable_int(GPIO_EJECT_BTN);
        gpio_ack_int(GPIO_EJECT_BTN);

        for (; curname < NUMNAMES; curname++) {
                printf("booting %s ", names[curname]);
                exec_netbsd(names[curname]);
        }

        panic("No bootable kernel found");

        return 0;
}

static int
exec_netbsd(const char *fname)
{
        u_long marks[MARK_MAX];
        void (*entry)(void);
        int fd;

        memset(marks, 0, sizeof(marks));
        fd = loadfile(fname, marks, LOAD_KERNEL);
        if (fd == -1) {
                return -1;
        }

        gpio_clear(GPIO_SLOT_LED);

        entry = (void *)marks[MARK_ENTRY];
        cache_dcbf((void *)marks[MARK_START],
                   marks[MARK_END] - marks[MARK_START]);
        cache_icbi((void *)marks[MARK_START],
                   marks[MARK_END] - marks[MARK_START]);

        entry();
        panic("Unexpected return from kernel");
}

__dead void
_rtt(void)
{
        int led = 0;
        for (;;) {
                if (led) {
                        gpio_set(GPIO_SLOT_LED);
                } else {
                        gpio_clear(GPIO_SLOT_LED);
                }
                for (int i = 0; i < 1000; i++) {
                        if ((in32(PI_INTERRUPT_CAUSE) & RESET_SWITCH_STATE) == 0) {
                                out32(HW_RESETS, in32(HW_RESETS) & ~RSTBINB);
                        }
                        timer_udelay(1000);
                }
                led ^= 1;
        }
}