#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// mips/nanonote/nanonote-boot.ccp: Host-side helper for booting over USB.
// Copyright 2009 Bas Wijnen <wijnen@debian.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, either version 3 of the License, or
// (at your option) any later version.
//
// 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, see <http://www.gnu.org/licenses/>.

#include <unistd.h>
#include <usb.h>
#include <fstream>
#include <sstream>
#include <iostream>
#include <iomanip>

asm volatile (".section .rodata\n"
	".globl stage1\n"
	".globl stage1_end\n"
	"stage1:\n"
	".incbin \"mips/nanonote/stage1.raw\"\n"
	"stage1_end:\n"
	".section .text")
extern char stage1[1]
extern char stage1_end[1]

unsigned const stage1_load = 0x80003000
unsigned const stage1_start = 0x80003000
unsigned const stage1_size = stage1_end - stage1

class nanonote:
	public:

	nanonote (unsigned skip = 0)
	void boot (std::string const &data, unsigned load, unsigned start)

	private:

	enum requests:
		VR_GET_CPU_INFO		= 0
		VR_SET_DATA_ADDRESS	= 1
		VR_SET_DATA_LENGTH	= 2
		VR_FLUSH_CACHES		= 3
		VR_PROGRAM_START1	= 4
		VR_PROGRAM_START2	= 5
	static int const vendor = 0x601a
	static int const product = 0x4740
	static unsigned const timeout = 1000
	usb_dev_handle *handle
	int interface
	int in_ep, out_ep
	std::string cpu_info
	bool try_open (struct usb_device *dev)
	bool find_device (unsigned skip)
	void request (requests num, unsigned data = 0)
	void send_file (unsigned address, unsigned size, char const *data)
	void get_cpu_info ()

bool nanonote::try_open (struct usb_device *dev):
	handle = usb_open (dev)

	if dev->descriptor.bNumConfigurations != 1:
		usb_close (handle)
		std::cerr << dev->descriptor.bNumConfigurations << " configurations\n"
		return false
	if usb_set_configuration (handle, 1) < 0:
		usb_close (handle)
		std::cerr << "Can't set configuration 1: " << usb_strerror () << '\n'
		return false

	interface = dev->config->interface->altsetting->bInterfaceNumber
	bool have_in = false, have_out = false
	for unsigned i = 0; i < dev->config->interface->altsetting->bNumEndpoints; ++i:
		if (dev->config->interface->altsetting->endpoint[i].bmAttributes & USB_ENDPOINT_TYPE_MASK) != USB_ENDPOINT_TYPE_BULK:
			usb_close (handle)
			std::cerr << "Device has non-bulk endpoint.\n"
			return false
		if (dev->config->interface->altsetting->endpoint[i].bEndpointAddress & USB_ENDPOINT_DIR_MASK):
			/* input */
			if have_in:
				usb_close (handle)
				std::cerr << "Device has multiple IN endpoints.\n"
				return false
			have_in = true
			in_ep = dev->config->interface->altsetting->endpoint[i].bEndpointAddress & USB_ENDPOINT_ADDRESS_MASK
			if in_ep != 1:
				usb_close (handle)
				std::cerr << "IN endpoint is not numbered as 1.\n"
				return false
		else:
			/* output */
			if have_out:
				usb_close (handle)
				std::cerr << "Device has multiple OUT endpoints.\n"
				return false
			have_out = true
			out_ep = dev->config->interface->altsetting->endpoint[i].bEndpointAddress & USB_ENDPOINT_ADDRESS_MASK
			if out_ep != 1:
				usb_close (handle)
				std::cerr << "OUT endpoint is not numbered as 1.\n"
				return false
	if usb_claim_interface (handle, interface) < 0:
		std::cerr << "unable to claim interface\n"
		return false
	return true

bool nanonote::find_device (unsigned skip):
	unsigned skipped = 0
	usb_init ()
	usb_find_busses ()
	usb_find_devices ()
	for struct usb_bus *bus = usb_busses; bus; bus = bus->next:
		for struct usb_device *dev = bus->devices; dev; dev = dev->next:
			if dev->descriptor.idProduct != product || dev->descriptor.idVendor != vendor:
				continue
			if skip > skipped++:
				continue
			if try_open (dev):
				return true
	return false

nanonote::nanonote (unsigned skip):
	if !find_device (skip):
		std::cerr << "unable to find NanoNote device.\n";
		throw "unable to find NanoNote device";
	// Get info will reset the device if it has already booted into Iris.
	get_cpu_info ()
	usb_close (handle)
	sleep (5)
	if !find_device (skip):
		std::cerr << "unable to find NanoNote device again.\n";
		throw "unable to find NanoNote device again";

void nanonote::get_cpu_info ():
	char buffer[8]
	if usb_control_msg (handle, USB_ENDPOINT_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, VR_GET_CPU_INFO, 0, 0, buffer, 8, timeout) < 0:
		std::cerr << "unable to request cpu info from NanoNote: " << usb_strerror () << ".\n"
		throw "unable to request cpu info from NanoNote"
	cpu_info = std::string (buffer, 8)

void nanonote::request (requests r, unsigned data):
	if usb_control_msg (handle, USB_ENDPOINT_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, r, (data >> 16) & 0xffff, data & 0xffff, NULL, 0, timeout) < 0:
		std::cerr << "unable to send control message to NanoNote: " << usb_strerror () << ".\n"
		throw "unable to send control message to NanoNote"

void nanonote::send_file (unsigned address, unsigned size, char const *data):
	request (VR_SET_DATA_ADDRESS, address)
	char const *ptr = data
	while ptr - data < size:
		int ret = usb_bulk_write (handle, out_ep, ptr, size - (ptr - data), timeout)
		if ret <= 0:
			std::cerr << "failed to write to NanoNote.\n"
			throw "failed to write to NanoNote"
		ptr += ret

void nanonote::boot (std::string const &data, unsigned load, unsigned start):
	send_file (stage1_load, stage1_size, stage1)
	request (VR_PROGRAM_START1, stage1_start)
	usleep (100)
	send_file (load, data.size (), data.data ())
	request (VR_FLUSH_CACHES)
	request (VR_PROGRAM_START2, start)

int main (int argc, char **argv):
	if argc != 3:
		std::cerr << "Usage: " << argv[0] << " [kernel] [entry address]\n"
		std::cerr << "The kernel is loaded from 0x80000000 and run from entry address\n"
		return 1
	unsigned entry = strtoul (argv[2], NULL, 0)
	nanonote nn
	std::ifstream file (argv[1])
	if !file:
		std::cerr << "can't open file '" << argv[1] << "' for reading.\n"
		return 1
	std::ostringstream data
	data << file.rdbuf ()
	if data.str ().empty ():
		std::cerr << "no data read from '" << argv[1] << "'.\n"
		return 1
	nn.boot (data.str (), 0x80000000, entry)
	return 0