mini/gecko.c

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

	boot2 chainloader

Copyright (C) 2008, 2009	Hector Martin "marcan" <marcan@marcansoft.com>
Copyright (C) 2008, 2009 	Sven Peter <svenpeter@gmail.com>

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 "powerpc.h"
#include "powerpc_elf.h"
#include "gecko.h"

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);
	i = 1000;
	while ((read32(EXI1_CR) & 1) && (i--));
	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;
}

#if 0
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 = 0;
	i = _gecko_command(0x90000000);
	if (i&0x04700000)
		return 1;
	return 0;
}

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

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);
}

#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);
}

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;
}

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);

	return gecko_sendbuffer(buffer, i);
}

// irq context

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

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) {
		// upload powerpc ELF
		case 0x43524150:
			_gecko_state = GECKO_STATE_RECEIVE_BUFFER_SIZE;
			_gecko_receive_len = 0;
			_gecko_receive_left = 4;
			_gecko_receive_buffer = (u8 *) 0x10100000;

			irq_set_alarm(1, 0);
			_gecko_cmd_start_time = read32(HW_TIMER);

			break;

		// upload ARM ELF
		case 0x5a4f4d47:
			_gecko_state = GECKO_STATE_RECEIVE_BUFFER_SIZE;
			_gecko_receive_len = 0;
			_gecko_receive_left = 4;
			_gecko_receive_buffer = (u8 *) 0x0; // yarly

			irq_set_alarm(1, 0);
			_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) {
			_gecko_state = GECKO_STATE_RECEIVE_BUFFER;
			_gecko_receive_left = _gecko_receive_len;

			// sorry pal, that memory is mine now
			powerpc_hang();
			gecko_printf("MINI/GECKO: PPC halted, receiving data...\n");
		}

		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;
	}

	// done receiving, handle the command
	switch (_gecko_cmd) {
	case 0x43524150:
		if (powerpc_boot_mem((u8 *) 0x10100000, _gecko_receive_len))
			gecko_printf("MINI/GECKO: the received binary is not a valid "
						"PPC ELF. Broadway is dead now.\n");
		break;

	case 0x5a4f4d47:
		// skip headerlen, which is stored at u32[0]
		ipc_queue_slow_jump(((u32 *) 0x0)[0]);
		break;
	}

cleanup:
	gecko_flush();

	irq_set_alarm(20, 0);

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