// license:BSD-3-Clause // copyright-holders:smf /* * x76f100.c * * Secure SerialFlash * * The X76F100 is a Password Access Security Supervisor, containing one 896-bit Secure SerialFlash array. * Access to the memory array can be controlled by two 64-bit passwords. These passwords protect read and * write operations of the memory array. * */ #include "emu.h" #include "x76f100.h" #include #include #define VERBOSE_LEVEL ( 0 ) inline void ATTR_PRINTF( 3, 4 ) x76f100_device::verboselog( int n_level, const char *s_fmt, ... ) { if( VERBOSE_LEVEL >= n_level ) { va_list v; char buf[32768]; va_start( v, s_fmt ); vsprintf( buf, s_fmt, v ); va_end( v ); logerror( "%s: x76f100(%s) %s", machine().describe_context(), tag(), buf ); } } // device type definition DEFINE_DEVICE_TYPE(X76F100, x76f100_device, "x76f100", "X76F100 Secure SerialFlash") x76f100_device::x76f100_device( const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock ) : device_t( mconfig, X76F100, tag, owner, clock ), device_nvram_interface(mconfig, *this), m_region(*this, DEVICE_SELF), m_cs( 0 ), m_rst( 0 ), m_scl( 0 ), m_sdaw( 0 ), m_sdar( 0 ), m_state( STATE_STOP ), m_shift( 0 ), m_bit( 0 ), m_byte( 0 ), m_command( 0 ), m_password_retry_counter( 0 ), m_is_password_accepted( false ) { } void x76f100_device::device_start() { std::fill( std::begin( m_write_buffer ), std::end( m_write_buffer ), 0 ); save_item( NAME( m_cs ) ); save_item( NAME( m_rst ) ); save_item( NAME( m_scl ) ); save_item( NAME( m_sdaw ) ); save_item( NAME( m_sdar ) ); save_item( NAME( m_state ) ); save_item( NAME( m_shift ) ); save_item( NAME( m_bit ) ); save_item( NAME( m_byte ) ); save_item( NAME( m_command ) ); save_item( NAME( m_password_retry_counter ) ); save_item( NAME( m_is_password_accepted ) ); save_item( NAME( m_write_buffer ) ); save_item( NAME( m_response_to_reset ) ); save_item( NAME( m_write_password ) ); save_item( NAME( m_read_password ) ); save_item( NAME( m_data ) ); } void x76f100_device::device_reset() { std::fill( std::begin( m_write_buffer ), std::end( m_write_buffer ), 0 ); m_cs = 0; m_rst = 0; m_scl = 0; m_sdaw = 0; m_sdar = 0; m_state = STATE_STOP; m_shift = 0; m_bit = 0; m_byte = 0; m_command = 0; m_password_retry_counter = 0; m_is_password_accepted = false; } void x76f100_device::write_cs(int state) { if( m_cs != state ) { verboselog( 2, "cs=%d\n", state ); } if( m_cs != 0 && state == 0 ) { /* enable chip */ m_state = STATE_STOP; } if( m_cs == 0 && state != 0 ) { /* disable chip */ m_state = STATE_STOP; /* high impendence? */ m_sdar = 0; } m_cs = state; } void x76f100_device::write_rst(int state) { if( m_rst != state ) { verboselog( 2, "rst=%d\n", state ); } if( m_rst == 0 && state != 0 && m_cs == 0 ) { verboselog( 1, "goto response to reset\n" ); m_state = STATE_RESPONSE_TO_RESET; m_bit = 0; m_byte = 0; } m_rst = state; } uint8_t *x76f100_device::password() { if( ( m_command & 0xe1 ) == COMMAND_READ ) { return m_read_password; } return m_write_password; } void x76f100_device::password_ok() { m_password_retry_counter = 0; if( ( m_command & 0x81 ) == COMMAND_READ ) { m_state = STATE_READ_DATA; } else if( ( m_command & 0x81 ) == COMMAND_WRITE ) { m_state = STATE_WRITE_DATA; } else { /* TODO: */ } } int x76f100_device::data_offset() { int block_offset = ( m_command >> 1 ) & 0x0f; int offset = ( block_offset * sizeof( m_write_buffer ) ) + m_byte; // Technically there are 4 bits assigned to sector values but since the data array is only 112 bytes, // it will try reading out of bounds when the sector is 14 (= starts at 112) or 15 (= starts at 120). // TODO: Verify what happens on real hardware when reading/writing sectors 14 and 15 if( offset >= sizeof ( m_data ) ) return -1; return offset; } void x76f100_device::write_scl(int state) { if( m_scl != state ) { verboselog( 2, "scl=%d\n", state ); } if( m_cs == 0 ) { switch( m_state ) { case STATE_STOP: break; case STATE_RESPONSE_TO_RESET: if( m_scl != 0 && state == 0 ) { if( m_bit == 0 ) { m_shift = m_response_to_reset[m_byte]; verboselog( 1, "<- response_to_reset[%d]: %02x\n", m_byte, m_shift ); } m_sdar = m_shift & 1; m_shift >>= 1; m_bit++; if( m_bit == 8 ) { m_bit = 0; m_byte++; if( m_byte == sizeof( m_response_to_reset ) ) { m_byte = 0; } } } break; case STATE_LOAD_COMMAND: case STATE_LOAD_PASSWORD: case STATE_VERIFY_PASSWORD: case STATE_WRITE_DATA: // FIXME: Processing on the rising edge of the clock causes sda to change state while clock is high // which is not allowed. Also need to ensure that only valid device-id's and commands // are acknowledged. if( m_scl == 0 && state != 0 ) { if( m_bit < 8 ) { verboselog( 2, "clock\n" ); m_shift <<= 1; if( m_sdaw != 0 ) { m_shift |= 1; } m_bit++; } else { m_sdar = 0; switch( m_state ) { case STATE_LOAD_COMMAND: m_command = m_shift; verboselog( 1, "-> command: %02x\n", m_command ); /* TODO: verify command is valid? */ m_state = STATE_LOAD_PASSWORD; break; case STATE_LOAD_PASSWORD: verboselog( 1, "-> password: %02x\n", m_shift ); m_write_buffer[m_byte++] = m_shift; if( m_byte == sizeof( m_write_buffer ) ) { m_state = STATE_VERIFY_PASSWORD; // Perform the password acceptance check before verify password because // password verify ack is spammed and will quickly overflow the // retry counter. This becomes an issue with System 573 games that use the // X76F100 as an install cartridge. The boot process first tries to use the // game cartridge password and if not accepted will try the install cartridge // password and then enter installation mode if accepted. m_is_password_accepted = memcmp( password(), m_write_buffer, sizeof( m_write_buffer ) ) == 0; if( !m_is_password_accepted ) { m_password_retry_counter++; if( m_password_retry_counter >= 8 ) { std::fill( std::begin( m_read_password ), std::end( m_read_password ), 0 ); std::fill( std::begin( m_write_password ), std::end( m_write_password ), 0 ); std::fill( std::begin( m_data ), std::end( m_data ), 0 ); m_password_retry_counter = 0; } } } break; case STATE_VERIFY_PASSWORD: verboselog( 1, "-> verify password: %02x\n", m_shift ); /* TODO: this should probably be handled as a command */ if( m_shift == COMMAND_ACK_PASSWORD ) { /* TODO: this should take 10ms before it returns ok. */ if( m_is_password_accepted ) { password_ok(); } else { m_sdar = 1; } } break; case STATE_WRITE_DATA: verboselog( 2, "-> data: %02x\n", m_shift ); m_write_buffer[m_byte++] = m_shift; if( m_byte == sizeof( m_write_buffer ) ) { if( m_command == COMMAND_CHANGE_WRITE_PASSWORD ) { std::copy( std::begin( m_write_buffer ), std::end( m_write_buffer ), std::begin( m_write_password ) ); } else if( m_command == COMMAND_CHANGE_READ_PASSWORD ) { std::copy( std::begin( m_write_buffer ), std::end( m_write_buffer ), std::begin( m_read_password ) ); } else { for( m_byte = 0; m_byte < sizeof( m_write_buffer ); m_byte++ ) { int offset = data_offset(); if( offset != -1 ) { verboselog( 1, "-> data[%03x]: %02x\n", offset, m_write_buffer[m_byte] ); m_data[offset] = m_write_buffer[m_byte]; } else { verboselog( 1, "-> attempted to write %02x out of bounds\n", m_write_buffer[m_byte] ); break; } } } m_byte = 0; verboselog( 1, "data flushed\n" ); } break; } m_bit = 0; m_shift = 0; } } break; case STATE_READ_DATA: // FIXME: Processing on the rising edge of the clock causes sda to change state while clock is high // which is not allowed. if( m_scl == 0 && state != 0 ) { if( m_bit < 8 ) { if( m_bit == 0 ) { int offset; switch( m_state ) { case STATE_READ_DATA: offset = data_offset(); if( offset != -1 ) { m_shift = m_data[offset]; verboselog( 1, "<- data[%02x]: %02x\n", offset, m_shift ); } else { m_shift = 0; verboselog( 1, "<- attempted to read out of bounds\n" ); } break; } } m_sdar = ( m_shift >> 7 ) & 1; m_shift <<= 1; m_bit++; } else { m_bit = 0; m_sdar = 0; if( m_sdaw == 0 ) { verboselog( 2, "ack <-\n" ); m_byte++; } else { verboselog( 2, "nak <-\n" ); } } } break; } } m_scl = state; } void x76f100_device::write_sda(int state) { if( m_sdaw != state ) { verboselog( 2, "sdaw=%d\n", state ); } if( m_cs == 0 && m_scl != 0 ) { if( m_sdaw == 0 && state != 0 ) { verboselog( 1, "goto stop\n" ); m_state = STATE_STOP; m_sdar = 0; } if( m_sdaw != 0 && state == 0 ) { switch( m_state ) { case STATE_STOP: verboselog( 1, "goto start\n" ); m_state = STATE_LOAD_COMMAND; break; case STATE_LOAD_PASSWORD: /* TODO: this will be the 0xc0 command, but it's not handled as a command yet. */ verboselog( 1, "goto start\n" ); break; case STATE_READ_DATA: verboselog( 1, "continue reading??\n" ); // verboselog( 1, "goto load address\n" ); // m_state = STATE_LOAD_ADDRESS; break; default: verboselog( 1, "skipped start (default)\n" ); break; } m_bit = 0; m_byte = 0; m_shift = 0; m_sdar = 0; } } m_sdaw = state; } int x76f100_device::read_sda() { if( m_cs != 0 ) { verboselog( 2, "not selected\n" ); return 1; } verboselog( 2, "sdar=%d\n", m_sdar ); return m_sdar; } void x76f100_device::nvram_default() { m_response_to_reset[0] = 0x19; m_response_to_reset[1] = 0x00; m_response_to_reset[2] = 0xaa; m_response_to_reset[3] = 0x55, memset( m_write_password, 0, sizeof( m_write_password ) ); memset( m_read_password, 0, sizeof( m_read_password ) ); memset( m_data, 0, sizeof( m_data ) ); int expected_size = sizeof( m_response_to_reset ) + sizeof( m_write_password ) + sizeof( m_read_password ) + sizeof( m_data ); if (!m_region.found()) { logerror( "x76f100(%s) region not found\n", tag() ); } else if( m_region->bytes() != expected_size ) { logerror("x76f100(%s) region length 0x%x expected 0x%x\n", tag(), m_region->bytes(), expected_size ); } else { uint8_t *region = m_region->base(); memcpy( m_response_to_reset, region, sizeof( m_response_to_reset )); region += sizeof( m_response_to_reset ); memcpy( m_write_password, region, sizeof( m_write_password )); region += sizeof( m_write_password ); memcpy( m_read_password, region, sizeof( m_read_password )); region += sizeof( m_read_password ); memcpy( m_data, region, sizeof( m_data )); region += sizeof( m_data ); } } bool x76f100_device::nvram_read( util::read_stream &file ) { std::error_condition err; size_t actual; std::tie( err, actual ) = read( file, m_response_to_reset, sizeof( m_response_to_reset ) ); if( err || ( sizeof( m_response_to_reset ) != actual ) ) return false; std::tie( err, actual ) = read( file, m_write_password, sizeof( m_write_password ) ); if( err || ( sizeof( m_write_password ) != actual ) ) return false; std::tie( err, actual ) = read( file, m_read_password, sizeof( m_read_password ) ); if( err || ( sizeof( m_read_password ) != actual ) ) return false; std::tie( err, actual ) = read( file, m_data, sizeof( m_data ) ); if( err || ( sizeof( m_data ) != actual ) ) return false; return true; } bool x76f100_device::nvram_write( util::write_stream &file ) { std::error_condition err; size_t actual; std::tie( err, actual ) = write( file, m_response_to_reset, sizeof( m_response_to_reset ) ); if ( err ) return false; std::tie( err, actual ) = write( file, m_write_password, sizeof( m_write_password ) ); if ( err ) return false; std::tie( err, actual ) = write( file, m_read_password, sizeof( m_read_password ) ); if ( err ) return false; std::tie( err, actual ) = write( file, m_data, sizeof( m_data ) ); if ( err ) return false; return true; }