/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2006 Wojciech A. Koszek <wkoszek@FreeBSD.org>
 * 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 AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/imgact.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/cons.h>
#include <sys/exec.h>
#include <sys/ucontext.h>
#include <sys/proc.h>
#include <sys/kdb.h>
#include <sys/ptrace.h>
#include <sys/reboot.h>
#include <sys/signalvar.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/user.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
#include <vm/vm_dumpset.h>

#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/cpuregs.h>
#include <machine/hwfunc.h>
#include <machine/md_var.h>
#include <machine/pmap.h>
#include <machine/trap.h>

#ifdef TICK_USE_YAMON_FREQ
#include <mips/malta/yamon.h>
#endif

#ifdef TICK_USE_MALTA_RTC
#include <mips/malta/maltareg.h>
#include <isa/rtc.h>
#endif

#include <mips/malta/maltareg.h>

extern int	*edata;
extern int	*end;

void	lcd_init(void);
void	lcd_puts(char *);
void	malta_reset(void);

/*
 * Temporary boot environment used at startup.
 */
static char boot1_env[4096];

/*
 * Offsets to MALTA LCD characters.
 */
static int malta_lcd_offs[] = {
	MALTA_ASCIIPOS0,
	MALTA_ASCIIPOS1,
	MALTA_ASCIIPOS2,
	MALTA_ASCIIPOS3,
	MALTA_ASCIIPOS4,
	MALTA_ASCIIPOS5,
	MALTA_ASCIIPOS6,
	MALTA_ASCIIPOS7
};

void
platform_cpu_init()
{
	/* Nothing special */
}

/*
 * Put character to Malta LCD at given position.
 */
static void
malta_lcd_putc(int pos, char c)
{
	void *addr;
	char *ch;

	if (pos < 0 || pos > 7)
		return;
	addr = (void *)(MALTA_ASCII_BASE + malta_lcd_offs[pos]);
	ch = (char *)MIPS_PHYS_TO_KSEG0(addr);
	*ch = c;
}

/*
 * Print given string on LCD.
 */
static void
malta_lcd_print(char *str)
{
	int i;

	if (str == NULL)
		return;

	for (i = 0; *str != '\0'; i++, str++)
		malta_lcd_putc(i, *str);
}

void
lcd_init(void)
{
	malta_lcd_print("FreeBSD_");
}

void
lcd_puts(char *s)
{
	malta_lcd_print(s);
}

#ifdef TICK_USE_MALTA_RTC
static __inline uint8_t
malta_rtcin(uint8_t addr)
{

	*((volatile uint8_t *)
	    MIPS_PHYS_TO_KSEG1(MALTA_PCI0_ADDR(MALTA_RTCADR))) = addr;
	return (*((volatile uint8_t *)
	    MIPS_PHYS_TO_KSEG1(MALTA_PCI0_ADDR(MALTA_RTCDAT))));
}

static __inline void
malta_writertc(uint8_t addr, uint8_t val)
{

	*((volatile uint8_t *)
	    MIPS_PHYS_TO_KSEG1(MALTA_PCI0_ADDR(MALTA_RTCADR))) = addr;
	*((volatile uint8_t *)
	    MIPS_PHYS_TO_KSEG1(MALTA_PCI0_ADDR(MALTA_RTCDAT))) = val;
}
#endif

static void
mips_init(unsigned long memsize, uint64_t ememsize)
{
	int i;

	for (i = 0; i < PHYS_AVAIL_ENTRIES; i++) {
		phys_avail[i] = 0;
	}

	/*
	 * memsize is the amount of RAM available below 256MB.
	 * ememsize is the total amount of RAM available.
	 *
	 * The second bank starts at 0x90000000.
	 */

	/* phys_avail regions are in bytes */
	phys_avail[0] = MIPS_KSEG0_TO_PHYS(kernel_kseg0_end);
	phys_avail[1] = memsize;
	dump_avail[0] = 0;
	dump_avail[1] = phys_avail[1];

	/* Only specify the extended region if it's set */
	if (ememsize > memsize) {
		phys_avail[2] = 0x90000000;
		phys_avail[3] = 0x90000000 + (ememsize - memsize);
		dump_avail[2] = phys_avail[2];
		dump_avail[3] = phys_avail[3];
	}

	/* XXX realmem assigned in the caller of mips_init() */
	physmem = realmem;

	init_param1();
	init_param2(physmem);
	mips_cpu_init();
	pmap_bootstrap();
	mips_proc0_init();
	mutex_init();
	kdb_init();
#ifdef KDB
	if (boothowto & RB_KDB)
		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
#endif
}

/*
 * Perform a board-level soft-reset.
 * Note that this is not emulated by gxemul.
 */
void
platform_reset(void)
{
	char *c;

	c = (char *)MIPS_PHYS_TO_KSEG0(MALTA_SOFTRES);
	*c = MALTA_GORESET;
}

static uint64_t
malta_cpu_freq(void)
{
	uint64_t platform_counter_freq = 0;

#if defined(TICK_USE_YAMON_FREQ)
	/*
	 * If we are running on a board which uses YAMON firmware,
	 * then query CPU pipeline clock from the syscon object.
	 * If unsuccessful, use hard-coded default.
	 */
	platform_counter_freq = yamon_getcpufreq();

#elif defined(TICK_USE_MALTA_RTC)
	/*
	 * If we are running on a board with the MC146818 RTC,
	 * use it to determine CPU pipeline clock frequency.
	 */
	u_int64_t counterval[2];

	/* Set RTC to binary mode. */
	malta_writertc(RTC_STATUSB, (malta_rtcin(RTC_STATUSB) | RTCSB_BCD));

	/* Busy-wait for falling edge of RTC update. */
	while (((malta_rtcin(RTC_STATUSA) & RTCSA_TUP) == 0))
		;
	while (((malta_rtcin(RTC_STATUSA)& RTCSA_TUP) != 0))
		;
	counterval[0] = mips_rd_count();

	/* Busy-wait for falling edge of RTC update. */
	while (((malta_rtcin(RTC_STATUSA) & RTCSA_TUP) == 0))
		;
	while (((malta_rtcin(RTC_STATUSA)& RTCSA_TUP) != 0))
		;
	counterval[1] = mips_rd_count();

	platform_counter_freq = counterval[1] - counterval[0];
#endif

	if (platform_counter_freq == 0)
		platform_counter_freq = MIPS_DEFAULT_HZ;

	return (platform_counter_freq);
}

void
platform_start(__register_t a0, __register_t a1,  __register_t a2, 
    __register_t a3)
{
	vm_offset_t kernend;
	uint64_t platform_counter_freq;
	int argc = a0;
	int32_t *argv = (int32_t*)a1;
	int32_t *envp = (int32_t*)a2;
	unsigned int memsize = a3;
	uint64_t ememsize = 0;
	int i;

	/* clear the BSS and SBSS segments */
	kernend = (vm_offset_t)&end;
	memset(&edata, 0, kernend - (vm_offset_t)(&edata));

	mips_postboot_fixup();

	mips_pcpu0_init();
	platform_counter_freq = malta_cpu_freq();
	mips_timer_early_init(platform_counter_freq);
	init_static_kenv(boot1_env, sizeof(boot1_env));

	cninit();
	printf("entry: platform_start()\n");

	bootverbose = 1;

	/* 
	 * YAMON uses 32bit pointers to strings so
	 * convert them to proper type manually
	 */

	if (bootverbose) {
		printf("cmd line: ");
		for (i = 0; i < argc; i++)
			printf("%s ", (char*)(intptr_t)argv[i]);
		printf("\n");
	}

	if (bootverbose)
		printf("envp:\n");

	/*
	 * Parse the environment for things like ememsize.
	 */
	for (i = 0; envp[i]; i += 2) {
		const char *a, *v;

		a = (char *)(intptr_t)envp[i];
		v = (char *)(intptr_t)envp[i+1];

		if (bootverbose)
			printf("\t%s = %s\n", a, v);

		if (strcmp(a, "ememsize") == 0) {
			ememsize = strtoul(v, NULL, 0);
		}
	}

	if (bootverbose) {
		printf("memsize = %llu (0x%08x)\n",
		    (unsigned long long) memsize, memsize);
		printf("ememsize = %llu\n", (unsigned long long) ememsize);

#ifdef __mips_o32
		/*
		 * For O32 phys_avail[] can't address memory beyond 2^32,
		 * so cap extended memory to 2GB minus one page.
		 */
		if (ememsize >= 2ULL * 1024 * 1024 * 1024)
			ememsize = 2ULL * 1024 * 1024 * 1024 - PAGE_SIZE;
#endif
	}

	/*
	 * For <= 256MB RAM amounts, ememsize should equal memsize.
	 * For > 256MB RAM amounts it's the total RAM available;
	 * split between two banks.
	 *
	 * XXX TODO: just push realmem assignment into mips_init() ?
	 */
	realmem = btoc(ememsize);
	mips_init(memsize, ememsize);

	mips_timer_init_params(platform_counter_freq, 0);
}