iris/source/udc.ccp

#pypp 0
// vim: set filetype=cpp : //
// Iris: micro-kernel for a capability-based operating system.
// boot-programs/udc.ccp: USB device controller driver.
// 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 "iris.hh"
#include "devices.hh"
#define ARCH
#include "arch.hh"

class Udc:
	typedef unsigned char u8
	typedef unsigned short u16
	typedef unsigned int u32
	typedef u8 string
	// The ugly stuff is because pypp doesn't support __attribute__.
	/**/struct Setup {
		u8 request_type;
		u8 request;
		u16 value;
		u16 index;
		u16 length;
	 } __attribute__ ((packed))
	/**/struct Device {
		static u8 const Type = 1;
		u8 length;
		u8 type;
		u16 usb_version;
		u8 dev_class;
		u8 subclass;
		u8 protocol;
		u8 max_packet_size0;
		u16 vendor;
		u16 product;
		u16 dev_version;
		string s_manufacturer;
		string s_product;
		string s_serial;
		u8 num_configurations;
	 } __attribute__ ((packed))
	/**/struct Configuration {
		static u8 const Type = 2;
		u8 length;
		u8 type;
		u16 total_length;
		u8 num_interfaces;
		u8 configuration_value;
		u8 configuration;
		u8 attributes;
		u8 max_power;
	 } __attribute__ ((packed))
	/**/struct Interface {
		static u8 const Type = 4;
		u8 length;
		u8 type;
		u8 interface;
		u8 alternate;
		u8 num_endpoints;
		u8 iface_class;
		u8 subclass;
		u8 protocol;
		string name;
	 } __attribute__ ((packed))
	/**/struct Endpoint {
		static u8 const Type = 5;
		u8 length;
		u8 type;
		u8 address;
		u8 attributes;
		u16 max_packet_size;
		u8 interval;
	 } __attribute__ ((packed))
	/**/struct Device_Qualifier {
		static u8 const Type = 6;
		u8 length;
		u8 type;
		u16 version;
		u8 dev_class;
		u8 subclass;
		u8 protocol;
		u8 max_packet_size0;
		u8 num_configurations;
		u8 reserved;
	 } __attribute__ ((packed))
	/**/struct Langs {
		static u8 const Type = 3;
		u8 length;
		u8 type;
		u8 lang;
	 } __attribute__ ((packed))
	template <unsigned size> struct String {
		static u8 const Type = 3;
		u8 length;
		u8 type;
		u16 data[size];
	 } __attribute__ ((packed))
	static unsigned const max_packet_size0 = 64
	static unsigned const max_packet_size_bulk = 64
	enum Requests:
		GET_STATUS = 0
		CLEAR_FEATURE = 1
		SET_FEATURE = 3
		SET_ADDRESS = 5
		GET_DESCRIPTOR = 6
		SET_DESCRIPTOR = 7
		GET_CONFIGURATION = 8
		SET_CONFIGURATION = 9
		GET_INTERFACE = 10
		SET_INTERFACE = 11
		SYNCH_FRAME = 12
	enum Request_types:
		STANDARD_TO_DEVICE = 0
		VENDOR_TO_DEVICE = 0x40
		STANDARD_FROM_DEVICE = 0x80
		VENDOR_FROM_DEVICE = 0xc0
	enum Endpoint_types:
		CONTROL = 0
		ISOCHRONOUS = 1
		BULK = 2
		INTERRUPT = 3
	/**/struct my_config {
		Configuration config;
		Interface interface;
		Endpoint endpoint[2];
	 } __attribute__ ((packed))
	static Device device_descriptor
	//static Device_Qualifier device_qualifier_descriptor
	static my_config config_descriptor; //, other_config_descriptor
	static String <1> s_langs
	static String <6> s_manufacturer
	static String <16> s_product
	enum State:
		IDLE
		TX
		RX
	State state
	char configuration
	unsigned size
	unsigned rx_request
	char const *ptr
	unsigned cmd_code, cmd_arg
	bool rebooting
	bool vendor (Setup *s, unsigned cmd)
	bool get_descriptor (unsigned type, unsigned idx, unsigned len)
	bool handle_setup (Setup *s, unsigned cmd)
	void irq_usb (unsigned cmd)
	void irq_in (unsigned cmd)
	void irq_out (unsigned cmd)
	char log_buffer[1000]
	unsigned log_buffer_size
	unsigned log_buffer_start
	Iris::Cap caller, caller_arg
	bool have_caller
	unsigned *page
	unsigned *p
	Iris::Page buffer_page
	public:
	void init ()
	void log (unsigned c)
	void interrupt (unsigned cmd)
	void send (unsigned code, unsigned narg, Iris::Cap reply, Iris::Cap arg)

Udc::Device Udc::device_descriptor = { sizeof (Device), Device::Type, 0x200, 0, 0, 0, max_packet_size0, 0xfffe, 0x0002, 0x100, 1, 2, 0, 1 }
Udc::my_config Udc::config_descriptor = {
	(Configuration){ sizeof (Configuration), Configuration::Type, sizeof (my_config), 1, 1, 0, 0xc0, 1 },
	(Interface){ sizeof (Interface), Interface::Type, 0, 0, 2, 0xff, 0, 0x80, 0 }, {
		(Endpoint){ sizeof (Endpoint), Endpoint::Type, 1, BULK, max_packet_size_bulk, 0 },
		(Endpoint){ sizeof (Endpoint), Endpoint::Type, 0x81, BULK, max_packet_size_bulk, 0 }
	}
 }
Udc::String <1> Udc::s_langs = { sizeof (String <1>), String <1>::Type, { 0x0409 } }
Udc::String <6> Udc::s_manufacturer = { sizeof (String <6>), String <6>::Type, { 's', 'h', 'e', 'v', 'e', 'k' } }
Udc::String <16> Udc::s_product = { sizeof (String <16>), String <16>::Type, { 'I', 'r', 'i', 's', ' ', 'o', 'n', ' ', 'N', 'a', 'n', 'o', 'N', 'o', 't', 'e' } }

//Udc::Device_Qualifier const Udc::device_qualifier_descriptor = { sizeof (Device_Qualifier), Device_Qualifier::Type, 0x200, 0, 0, 0, max_packet_size0, 1, 0 }
//Udc::my_config const Udc::other_config_descriptor = {
//	(Configuration){ sizeof (Configuration), 7, sizeof (my_config), 1, 1, 0, 0xc0, 1 },
//	(Interface){ sizeof (Interface), Interface::Type, 0, 0, 2, 0xff, 0, 0x80, 0 }, {
//		(Endpoint){ sizeof (Endpoint), Endpoint::Type, 1, BULK, max_packet_size_bulk, 0 },
//		(Endpoint){ sizeof (Endpoint), Endpoint::Type, 0x81, BULK, max_packet_size_bulk, 0 }
//	}
// }

void Udc::init ():
	// Initialize the globals.  My method of compiling doesn't do that properly.
	device_descriptor = (Device){ sizeof (Device), Device::Type, 0x200, 0, 0, 0, max_packet_size0, 0xfffe, 0x0002, 0x100, 1, 2, 0, 1 }
	config_descriptor = (my_config){
		(Configuration){ sizeof (Configuration), Configuration::Type, sizeof (my_config), 1, 1, 0, 0xc0, 1 },
		(Interface){ sizeof (Interface), Interface::Type, 0, 0, 2, 0xff, 0, 0x80, 0 }, {
			(Endpoint){ sizeof (Endpoint), Endpoint::Type, 1, BULK, max_packet_size_bulk, 0 },
			(Endpoint){ sizeof (Endpoint), Endpoint::Type, 0x81, BULK, max_packet_size_bulk, 0 }
		}
	 }
	s_langs = (String <1>){ sizeof (String <1>), String <1>::Type, { 0x0409 } }
	s_manufacturer = (String <6>){ sizeof (String <6>), String <6>::Type, { 's', 'h', 'e', 'v', 'e', 'k' } }
	s_product = (String <16>){ sizeof (String <16>), String <16>::Type, { 'I', 'r', 'i', 's', ' ', 'o', 'n', ' ', 'N', 'a', 'n', 'o', 'N', 'o', 't', 'e' } }
	have_caller = false
	log_buffer_size = 0
	log_buffer_start = 0
	cmd_code = ~0
	cmd_arg = 0

	// Use the space which is reserved for the framebuffer, because it will not be in use.
	// Normally a normal new page should be allocated here, but new isn't implemented at this point.
	page = (unsigned *)LCD_FRAMEBUFFER_BASE
	p = page
	buffer_page = Iris::my_memory.create_page ()
	buffer_page.set_flags (Iris::Page::FRAME | Iris::Page::PAYING)
	Iris::my_memory.map (buffer_page, (unsigned)page)

	// Disconnect from the bus and don't try to get high-speed.
	UDC_POWER = 0
	UDC_TESTMODE = 0
	UDC_INDEX = 0
	state = IDLE
	configuration = 0
	size = 0
	// exit suspend mode by reading the interrupt register.
	cpm_start_udc ()
	// reset all pending endpoint interrupts.
	unsigned i = UDC_INTRUSB
	i = UDC_INTRIN
	i = UDC_INTROUT
	// enable interrupt on bus reset.
	UDC_INTRUSBE = UDC_INTR_RESET
	// enable interrupts on endpoint 0.
	UDC_INTRINE = 1 << 0
	// and on out endpoint 1.
	UDC_INTROUTE = 1 << 1
	// Wait a while.
	for unsigned w = 0; w < 10000; ++w:
		Iris::schedule ()
	// Connect to the host.
	UDC_POWER = UDC_POWER_SOFTCONN

bool Udc::vendor (Setup *s, unsigned cmd):
	if !(s->request_type & 0x80):
		kdebug ("data to device without size\n")
		Iris::panic (0)
		return true
	if s->request == 10:
		static unsigned b[2]
		ptr = (char *)b
		size = s->length < 8 ? s->length : 8
		if cmd_code != ~0:
			b[0] = cmd_code
			b[1] = cmd_arg
			if cmd_code == Iris::Directory::LOCK_RO || cmd_code == Iris::Directory::UNLOCK_RO:
				caller.invoke ()
				Iris::free_cap (caller)
				Iris::free_cap (caller_arg)
				have_caller = false
				//kdebug ("(un)lock response\n")
			cmd_code = ~0
		else:
			if log_buffer_start == log_buffer_size:
				b[0] = ~1
				b[1] = 0
			else:
				b[0] = ~0
				b[1] = (log_buffer[log_buffer_start++] & 0xff) * 0x01010101
			if log_buffer_start == log_buffer_size:
				log_buffer_start = 0
				log_buffer_size = 0
	else:
		static char const *name = "Reboot"
		ptr = name
		size = s->length < 6 ? s->length : 6
		rebooting = true
	state = TX
	return true

void Udc::send (unsigned code, unsigned narg, Iris::Cap reply, Iris::Cap arg):
	if cmd_code != ~0:
		kdebug ("new code sent while old one wasn't finished.\n")
		Iris::panic (0)
	cmd_code = code
	cmd_arg = narg
	caller = reply
	caller_arg = arg
	have_caller = true

bool Udc::get_descriptor (unsigned type, unsigned idx, unsigned len):
	switch type:
		case Configuration::Type:
			if idx != 0:
				return false
			ptr = reinterpret_cast <char const *> (&config_descriptor)
			size = (len < sizeof (config_descriptor) ? len : sizeof (config_descriptor))
			break
		case Device::Type:
			if idx != 0:
				return false
			ptr = reinterpret_cast <char const *> (&device_descriptor)
			size = (len < sizeof (device_descriptor) ? len : sizeof (device_descriptor))
			break
		case Device_Qualifier::Type:
			//if idx != 0:
			//	return false
			//ptr = reinterpret_cast <char const *> (&device_qualifier_descriptor)
			//size = (len < sizeof (device_qualifier_descriptor) ? len : sizeof (device_qualifier_descriptor))
			//break
			return false
		// The 6 is an arbitrary number, except that String <6> is instantiated already.
		case String <6>::Type:
			switch idx:
				case 0:
					ptr = reinterpret_cast <char const *> (&s_langs)
					size = (len < sizeof (s_langs) ? len : sizeof (s_langs))
					break
				case 1:
					ptr = reinterpret_cast <char const *> (&s_manufacturer)
					size = (len < sizeof (s_manufacturer) ? len : sizeof (s_manufacturer))
					break
				case 2:
					ptr = reinterpret_cast <char const *> (&s_product)
					size = (len < sizeof (s_product) ? len : sizeof (s_product))
					break
				default:
					return false
			break
		default:
			return false
	state = TX
	return true

bool Udc::handle_setup (Setup *s, unsigned cmd):
	switch s->request_type:
		case STANDARD_TO_DEVICE:
			switch s->request:
				case SET_ADDRESS:
					UDC_FADDR = s->value
					break
				case SET_CONFIGURATION:
					if s->value >= 2:
						return false
					configuration = s->value
					break
				case SET_INTERFACE:
					if s->value != 0:
						return false
					break
				default:
					return false
			UDC_OUTMAXP = 64
			UDC_OUTCSR = UDC_OUTCSR_CDT | UDC_OUTCSR_FF
			UDC_OUTCSR = UDC_OUTCSR_CDT | UDC_OUTCSR_FF
			break
		case STANDARD_FROM_DEVICE:
			switch s->request:
				case GET_STATUS:
					ptr = "\0\0"
					size = (s->length < 2 ? s->length : 2)
					state = TX
					break
				case GET_DESCRIPTOR:
					return get_descriptor ((s->value >> 8) & 0xff, s->value & 0xff, s->length)
				case GET_CONFIGURATION:
					ptr = &configuration
					size = (s->length < 1 ? s->length : 1)
					state = TX
					break
				case GET_INTERFACE:
					ptr = "\0"
					size = (s->length < 1 ? s->length : 1)
					state = TX
					break
				default:
					return false
			break
		case VENDOR_TO_DEVICE:
		case VENDOR_FROM_DEVICE:
			return vendor (s, cmd)
		default:
			return false
	return true

void Udc::irq_usb (unsigned cmd):
	// Reset.
	//Iris::debug ("usb reset\n")
	state = IDLE

void Udc::irq_in (unsigned cmd):
	// Interrupt on endpoint 0.
	unsigned csr = UDC_CSR0
	if csr & UDC_CSR0_SENTSTALL:
		csr &= ~(UDC_CSR0_SENTSTALL | UDC_CSR0_SENDSTALL)
		state = IDLE
	if csr & UDC_CSR0_SETUPEND:
		csr |= UDC_CSR0_SVDSETUPEND
		state = IDLE
	switch state:
		case IDLE:
			if rebooting:
				Iris::reboot ()
			if !(csr & UDC_CSR0_OUTPKTRDY):
				return
			union { unsigned d[2]; Setup s; } packet
			packet.d[0] = UDC_FIFO (0)
			packet.d[1] = UDC_FIFO (0)
			if !(packet.s.request_type & 0x80) && packet.s.length > 0:
				// More data will follow; delay handling of packet.
				state = RX
				UDC_CSR0 = csr | UDC_CSR0_SVDOUTPKTRDY
				rx_request = packet.s.request
				return
			UDC_CSR0 = csr | UDC_CSR0_DATAEND | UDC_CSR0_SVDOUTPKTRDY
			if !handle_setup (&packet.s, cmd):
				csr |= UDC_CSR0_SENDSTALL
				break
			if size == 0:
				return
			// Fall through.
		case TX:
			unsigned i
			for i = 0; (size & ~3) > 0 && i < max_packet_size0; i += 4, size -= 4:
				UDC_FIFO (0) = *(unsigned *)ptr
				ptr += 4
			for ; size > 0 && i < max_packet_size0; ++i, --size:
				UDC_FIFO8 (0) = *ptr++
			if i == max_packet_size0:
				csr |= UDC_CSR0_INPKTRDY
			else:
				state = IDLE
				csr |= UDC_CSR0_INPKTRDY | UDC_CSR0_DATAEND
			break
		case RX:
			// The protocol that is used doesn't allow large packets, so being here always means the entire packet is received.
			switch rx_request & 0xff:
				case Iris::Directory::GET_SIZE & 0xff:
					if !have_caller:
						kdebug ("received dir size from server without a caller waiting\n")
						Iris::panic (0)
					unsigned size_l = UDC_FIFO (0)
					unsigned size_h = UDC_FIFO (0)
					caller.invoke (Iris::Num (size_l, size_h))
					Iris::free_cap (caller)
					Iris::free_cap (caller_arg)
					have_caller = false
					//kdebug ("get_size response\n")
					break
				case Iris::Directory::GET_NAME & 0xff:
					if !have_caller:
						kdebug ("received filename from server without a caller waiting\n")
						Iris::panic (0)
					unsigned n[4]
					for unsigned i = 0; i < 4; ++i:
						n[i] = UDC_FIFO (0)
					caller.invoke (Iris::Num (n[0], n[1]), Iris::Num (n[2], n[3]))
					Iris::free_cap (caller)
					Iris::free_cap (caller_arg)
					//kdebug ("get_name response\n")
					have_caller = false
					break
				case Iris::String::GET_SIZE & 0xff:
					if !have_caller:
						kdebug ("received string size from server without a caller waiting\n")
						Iris::panic (0)
					unsigned size_l = UDC_FIFO (0)
					unsigned size_h = UDC_FIFO (0)
					caller.invoke (Iris::Num (size_l, size_h))
					Iris::free_cap (caller)
					Iris::free_cap (caller_arg)
					have_caller = false
					//kdebug ("get_filesize response\n")
					break
				case Iris::String::GET_CHARS & 0xff:
					if !have_caller:
						kdebug ("received string char data from server without a caller waiting\n")
						Iris::panic (0)
					unsigned n[4]
					for unsigned i = 0; i < 4; ++i:
						n[i] = UDC_FIFO (0)
					caller.invoke (Iris::Num (n[0], n[1]), Iris::Num (n[2], n[3]))
					Iris::free_cap (caller)
					Iris::free_cap (caller_arg)
					have_caller = false
					//kdebug ("get_chars response\n")
					break
				default:
					kdebug ("invalid vendor request: ")
					kdebug_num (rx_request)
					kdebug ("\n")
					Iris::panic (0)
			UDC_CSR0 = csr | UDC_CSR0_DATAEND | UDC_CSR0_SVDOUTPKTRDY
			state = IDLE
			break
	UDC_CSR0 = csr

void Udc::irq_out (unsigned cmd):
	// Interrupt on OUT endpoint 1.
	UDC_INDEX = 1
	if !have_caller:
		kdebug ("received bulk data from server without a caller waiting\n")
		Iris::panic (0)
	unsigned size = UDC_OUTCOUNT
	unsigned csr = UDC_OUTCSR
	//Iris::debug ("handling bulk interrupt for %x with %d bytes.\n", csr, size)
	csr &= ~UDC_OUTCSR_OUTPKTRDY
	for unsigned i = 0; i < size; i += 4:
		*p++ = UDC_FIFO (1)
	if p - page == PAGE_SIZE >> 2:
		buffer_page.share (caller_arg, Iris::Page::FORGET)
		buffer_page.set_flags (Iris::Page::FRAME)
		caller.invoke ()
		Iris::free_cap (caller)
		Iris::free_cap (caller_arg)
		have_caller = false
		//kdebug ("bulk response\n")
		p = page
	UDC_OUTCSR = csr
	UDC_INDEX = 0

void Udc::interrupt (unsigned cmd):
	while true:
		unsigned usb = UDC_INTRUSB
		unsigned in = UDC_INTRIN
		unsigned out = UDC_INTROUT
		if !(usb & 4) && !(in & 1) && !(out & 2):
			break
		//Iris::debug ("interrupt: %d/%d/%d\n", usb, in, out)
		if usb & 4:
			irq_usb (cmd)
		if in & 1:
			irq_in (cmd)
		if out & 2:
			irq_out (cmd)

void Udc::log (unsigned c):
	if log_buffer_size >= sizeof (log_buffer):
		return
	log_buffer[log_buffer_size++] = c

enum pdata:
	LOG = 1
	DIRECTORY
	FILE
	NAME

Iris::Num start ():
	Iris::debug ("udc started")
	map_udc ()
	map_gpio ()
	map_cpm ()
	Udc udc

	//Iris::Cap logcap = Iris::my_receiver.create_capability (LOG)
	//__asm__ volatile ("li $a0, 1\nlw $a1, %0\nbreak" :: "m"(logcap.code): "a0", "a1")
	Iris::Directory dir = Iris::my_receiver.create_capability (DIRECTORY)
	Iris::my_parent.provide_capability <Iris::Directory> (dir.copy ())
	Iris::free_cap (dir)
	udc.init ()
	Iris::register_interrupt (IRQ_UDC)
	// Don't call init_done, because this can be used as bootthread and without a parent this call will not be answered.
	//Iris::my_parent.init_done ()
	unsigned state = 0
	while true:
		Iris::wait ()
		Iris::Cap reply = Iris::get_reply ()
		Iris::Cap arg = Iris::get_arg ()
		//Iris::debug ("udc event, protected: %x\n", Iris::recv.protected_data.l)
		switch Iris::recv.protected_data.l:
			case 0:
				udc.interrupt (state)
				Iris::register_interrupt (IRQ_UDC)
				break
			case LOG:
				udc.log (Iris::recv.data[0].l)
				break
			case DIRECTORY:
				//Iris::debug ("dir request %d\n", Iris::recv.data[0].l)
				switch Iris::recv.data[0].l:
					case Iris::Directory::GET_NAME:
						Iris::Cap name = Iris::my_receiver.create_capability (Iris::Num (NAME, Iris::recv.data[1].l))
						reply.invoke (0, 0, name.copy ())
						Iris::free_cap (name)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
					case Iris::Directory::GET_SIZE:
					case Iris::Directory::LOCK_RO:
					case Iris::Directory::UNLOCK_RO:
						state = Iris::recv.data[0].l
						if Iris::recv.data[1].h != 0:
							Iris::panic (0, "index out of supported range")
						udc.send (Iris::recv.data[0].l, Iris::recv.data[1].l, reply, arg)
						continue
					case Iris::Directory::GET_FILE_RO:
						if Iris::recv.data[1].h != 0:
							kdebug ("index out of supported range\n")
							Iris::panic (0)
						//kdebug ("sending file\n")
						Iris::Cap file = Iris::my_receiver.create_capability (Iris::Num (FILE, Iris::recv.data[1].l))
						reply.invoke (0, 0, file.copy ())
						Iris::free_cap (file)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
					case Iris::Directory::GET_FILE_INFO:
					default:
						reply.invoke (Iris::ERR_INVALID_OPERATION)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
				break
			case FILE:
				//Iris::debug ("file request %d\n", Iris::recv.data[0].l)
				switch Iris::recv.data[0].l:
					case Iris::Block::GET_BLOCK:
						if Iris::recv.data[0].h != PAGE_SIZE << 16:
							Iris::panic (0, "unsupported get_block arguments for boot usb device driver")
						// Fall through.
					case Iris::Block::GET_SIZE:
						udc.send (Iris::recv.data[0].l | ((Iris::recv.data[1].l >> PAGE_BITS) << 16), Iris::recv.protected_data.h, reply, arg)
						continue
					default:
						reply.invoke (Iris::ERR_INVALID_OPERATION)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
				break
			case NAME:
				//Iris::debug ("name request %d\n", Iris::recv.data[0].l)
				switch Iris::recv.data[0].l:
					case Iris::String::GET_SIZE:
						reply.invoke (16)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
					case Iris::String::GET_CHARS:
						state = Iris::recv.data[0].l
						udc.send (Iris::Directory::GET_NAME, Iris::recv.protected_data.h, reply, arg)
						continue
					default:
						reply.invoke (Iris::ERR_INVALID_OPERATION)
						Iris::free_cap (reply)
						Iris::free_cap (arg)
						continue
			default:
				kdebug ("other request:")
				kdebug_num (Iris::recv.protected_data.l)
				kdebug ("\n")
				udc.log ('~')
				char digit[] = "0123456789abcdef"
				for unsigned i = 0; i < 8; ++i:
					udc.log (digit[(Iris::recv.protected_data.l >> (4 * (7 - i))) & 0xf])
				udc.log ('\n')
				break
		reply.invoke ()
		Iris::free_cap (reply)
		Iris::free_cap (arg)