mini/gecko.c

/*
	mini - a Free Software replacement for the Nintendo/BroadOn IOS.

	boot2 chainloader

Copyright (c) 2008			Nuke - <wiinuke@gmail.com>
Copyright (C) 2008, 2009	Hector Martin "marcan" <marcan@marcansoft.com>
Copyright (C) 2008, 2009	Sven Peter <svenpeter@gmail.com>
Copyright (C) 2009			Andre Heider "dhewg" <dhewg@wiibrew.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 2.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/
#include "types.h"
#include "irq.h"
#include "start.h"
#include "vsprintf.h"
#include "string.h"
#include "utils.h"
#include "hollywood.h"
#include "elf.h"
#include "powerpc.h"
#include "powerpc_elf.h"
#include "gecko.h"

//#define GECKO_SAFE

static u8 gecko_console_enabled = 0;

static u32 _gecko_command(u32 command)
{
	u32 i;
	// Memory Card Port B (Channel 1, Device 0, Frequency 3 (32Mhz Clock))
	write32(EXI1_CSR, 0xd0);
	write32(EXI1_DATA, command);
	write32(EXI1_CR, 0x19);
	while (read32(EXI1_CR) & 1);
	i = read32(EXI1_DATA);
	write32(EXI1_CSR, 0);
	return i;
}

static u32 _gecko_getid(void)
{
	u32 i;
	// Memory Card Port B (Channel 1, Device 0, Frequency 3 (32Mhz Clock))
	write32(EXI1_CSR, 0xd0);
	write32(EXI1_DATA, 0);
	write32(EXI1_CR, 0x19);
	while (read32(EXI1_CR) & 1);
	write32(EXI1_CR, 0x39);
	while (read32(EXI1_CR) & 1);
	i = read32(EXI1_DATA);
	write32(EXI1_CSR, 0);
	return i;
}

static u32 _gecko_sendbyte(u8 sendbyte)
{
	u32 i = 0;
	i = _gecko_command(0xB0000000 | (sendbyte<<20));
	if (i&0x04000000)
		return 1; // Return 1 if byte was sent
	return 0;
}

static u32 _gecko_recvbyte(u8 *recvbyte)
{
	u32 i = 0;
	*recvbyte = 0;
	i = _gecko_command(0xA0000000);
	if (i&0x08000000) {
		// Return 1 if byte was received
		*recvbyte = (i>>16)&0xff;
		return 1;
	}
	return 0;
}

#ifdef GECKO_SAFE
static u32 _gecko_checksend(void)
{
	u32 i = 0;
	i = _gecko_command(0xC0000000);
	if (i&0x04000000)
		return 1; // Return 1 if safe to send
	return 0;
}
#endif

static u32 _gecko_checkrecv(void)
{
	u32 i = 0;
	i = _gecko_command(0xD0000000);
	if (i&0x04000000)
		return 1; // Return 1 if safe to recv
	return 0;
}

static int gecko_isalive(void)
{
	u32 i;

	i = _gecko_getid();
	if (i != 0x00000000)
		return 0;

	i = _gecko_command(0x90000000);
	if ((i & 0xFFFF0000) != 0x04700000)
		return 0;

	return 1;
}

static void gecko_flush(void)
{
	u8 tmp;
	while(_gecko_recvbyte(&tmp));
}

#if 0
static int gecko_recvbuffer(void *buffer, u32 size)
{
	u32 left = size;
	char *ptr = (char*)buffer;

	while(left>0) {
		if(!_gecko_recvbyte(ptr))
			break;
		ptr++;
		left--;
	}
	return (size - left);
}
#endif

#ifndef GECKO_SAFE
static int gecko_sendbuffer(const void *buffer, u32 size)
{
	u32 left = size;
	char *ptr = (char*)buffer;

	while(left>0) {
		if(!_gecko_sendbyte(*ptr))
			break;
		ptr++;
		left--;
	}
	return (size - left);
}
#endif

#if 0
static int gecko_recvbuffer_safe(void *buffer, u32 size)
{
	u32 left = size;
	char *ptr = (char*)buffer;
	
	while(left>0) {
		if(_gecko_checkrecv()) {
			if(!_gecko_recvbyte(ptr))
				break;
			ptr++;
			left--;
		}
	}
	return (size - left);
}
#endif

#ifdef GECKO_SAFE
static int gecko_sendbuffer_safe(const void *buffer, u32 size)
{
	u32 left = size;
	char *ptr = (char*)buffer;

	if((read32(HW_EXICTRL) & EXICTRL_ENABLE_EXI) == 0)
		return left;
	
	while(left>0) {
		if(_gecko_checksend()) {
			if(!_gecko_sendbyte(*ptr))
				break;
			ptr++;
			left--;
		}
	}
	return (size - left);
}
#endif

void gecko_init(void)
{
	write32(EXI0_CSR, 0);
	write32(EXI1_CSR, 0);
	write32(EXI2_CSR, 0);
	write32(EXI0_CSR, 0x2000);
	write32(EXI0_CSR, 3<<10);
	write32(EXI1_CSR, 3<<10);

	if (!gecko_isalive())
		return;

	gecko_flush();
	gecko_console_enabled = 1;
}

u8 gecko_enable_console(const u8 enable)
{
	if (enable) {
		if (gecko_isalive())
			gecko_console_enabled = 1;
	} else
		gecko_console_enabled = 0;

	return gecko_console_enabled;
}

#ifndef NDEBUG
int gecko_printf(const char *fmt, ...)
{
	if (!gecko_console_enabled)
		return 0;

	va_list args;
	char buffer[256];
	int i;

	va_start(args, fmt);
	i = vsprintf(buffer, fmt, args);
	va_end(args);

#ifdef GECKO_SAFE
	return gecko_sendbuffer_safe(buffer, i);
#else
	return gecko_sendbuffer(buffer, i);
#endif
}
#endif

// irq context

#define GECKO_STATE_NONE 0
#define GECKO_STATE_RECEIVE_BUFFER_SIZE 1
#define GECKO_STATE_RECEIVE_BUFFER 2

#define GECKO_BUFFER_MAX (20 * 1024 * 1024)

#define GECKO_CMD_BIN_ARM 0x4241524d
#define GECKO_CMD_BIN_PPC 0x42505043

static u32 _gecko_cmd = 0;
static u32 _gecko_cmd_start_time = 0;
static u32 _gecko_state = GECKO_STATE_NONE;
static u32 _gecko_receive_left = 0;
static u32 _gecko_receive_len = 0;
static u8 *_gecko_receive_buffer = NULL;

void gecko_timer_initialize(void)
{
	if (!gecko_isalive())
		return;

	irq_set_alarm(20, 1);
}

void gecko_timer(void) {
	u8 b;

	if (_gecko_cmd_start_time && read32(HW_TIMER) >
			(_gecko_cmd_start_time + IRQ_ALARM_MS2REG(5000)))
		goto cleanup;

	switch (_gecko_state) {
	case GECKO_STATE_NONE:
		if (!_gecko_checkrecv() || !_gecko_recvbyte(&b))
			return;

		_gecko_cmd <<= 8;
		_gecko_cmd |= b;

		switch (_gecko_cmd) {
		case GECKO_CMD_BIN_ARM:
			_gecko_state = GECKO_STATE_RECEIVE_BUFFER_SIZE;
			_gecko_receive_len = 0;
			_gecko_receive_left = 4;
			_gecko_receive_buffer = (u8 *) 0x0; // yarly

			_gecko_cmd_start_time = read32(HW_TIMER);

			break;

		case GECKO_CMD_BIN_PPC:
			_gecko_state = GECKO_STATE_RECEIVE_BUFFER_SIZE;
			_gecko_receive_len = 0;
			_gecko_receive_left = 4;
			_gecko_receive_buffer = (u8 *) 0x10100000;

			_gecko_cmd_start_time = read32(HW_TIMER);

			break;
		}

		return;

	case GECKO_STATE_RECEIVE_BUFFER_SIZE:
		if (!_gecko_checkrecv() || !_gecko_recvbyte(&b))
			return;

		_gecko_receive_len <<= 8;
		_gecko_receive_len |= b;
		_gecko_receive_left--;

		if (!_gecko_receive_left) {
			if (_gecko_receive_len > GECKO_BUFFER_MAX)
				goto cleanup;

			_gecko_state = GECKO_STATE_RECEIVE_BUFFER;
			_gecko_receive_left = _gecko_receive_len;

			// sorry pal, that memory is mine now
			powerpc_hang();
		}

		return;

	case GECKO_STATE_RECEIVE_BUFFER:
		while (_gecko_receive_left) {
			if (!_gecko_checkrecv() || !_gecko_recvbyte(_gecko_receive_buffer))
				return;

			_gecko_receive_buffer++;
			_gecko_receive_left--;
		}

		if (!_gecko_receive_left)
			break;

		return;

	default:
		gecko_printf("MINI/GECKO: internal error\n");
		return;
	}

	ioshdr *h;

	// done receiving, handle the command
	switch (_gecko_cmd) {
	case GECKO_CMD_BIN_ARM:
		h = (ioshdr *) (u32 *) 0x0;

		if (h->hdrsize != sizeof (ioshdr))
			goto cleanup;

		if (memcmp("\x7F" "ELF\x01\x02\x01",
					(void *) (h->hdrsize + h->loadersize), 7))
			goto cleanup;

		ipc_enqueue_slow(IPC_DEV_SYS, IPC_SYS_JUMP, 1, h->hdrsize);
		break;

	case GECKO_CMD_BIN_PPC:
		ipc_enqueue_slow(IPC_DEV_PPC, IPC_PPC_BOOT, 3,
							1, (u32) 0x10100000, _gecko_receive_len);
		break;
	}

cleanup:
	gecko_flush();

	_gecko_cmd = 0;
	_gecko_cmd_start_time = 0;
	_gecko_state = GECKO_STATE_NONE;
}