mame/src/devices/machine/x76f041.cpp
2015-12-20 05:39:25 +01:00

541 lines
12 KiB
C++

// license:BSD-3-Clause
// copyright-holders:smf
/*
* x76f041.c
*
* Secure SerialFlash
*
* The X76F041 is a Password Access Security Supervisor, containing four 128 x 8 bit SecureFlash arrays.
* Access can be controlled by three 64-bit programmable passwords, one for read operations, one for write
* operations and one for device configuration.
*
* The data sheet has an incorrect diagrams for sequential read with password, there shouldn't be an extra address after the 0xc0 command.
*
*/
#include "emu.h"
#include "machine/x76f041.h"
#define VERBOSE_LEVEL ( 0 )
inline void ATTR_PRINTF( 3, 4 ) x76f041_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: x76f041(%s) %s", machine().describe_context(), tag(), buf );
}
}
// device type definition
const device_type X76F041 = &device_creator<x76f041_device>;
x76f041_device::x76f041_device( const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock )
: device_t( mconfig, X76F041, "Xicor X76F041 Flash", tag, owner, clock, "x76f041", __FILE__ ),
device_nvram_interface(mconfig, *this),
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_address( 0 )
{
}
void x76f041_device::device_start()
{
memset( m_write_buffer, 0, sizeof( m_write_buffer ) );
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_address ) );
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_configuration_password ) );
save_item( NAME( m_configuration_registers ) );
save_item( NAME( m_data ) );
}
WRITE_LINE_MEMBER( x76f041_device::write_cs )
{
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;
}
WRITE_LINE_MEMBER( x76f041_device::write_rst )
{
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 *x76f041_device::password()
{
switch( m_command & 0xe0 )
{
case COMMAND_WRITE:
return m_write_password;
case COMMAND_READ:
return m_read_password;
default:
return m_configuration_password;
}
}
void x76f041_device::password_ok()
{
switch( m_command & 0xe0 )
{
case COMMAND_WRITE:
m_state = STATE_WRITE_DATA;
break;
case COMMAND_READ:
m_state = STATE_READ_DATA;
break;
case COMMAND_WRITE_USE_CONFIGURATION_PASSWORD:
m_state = STATE_WRITE_DATA;
break;
case COMMAND_READ_USE_CONFIGURATION_PASSWORD:
m_state = STATE_READ_DATA;
break;
case COMMAND_CONFIGURATION:
switch( m_address )
{
case CONFIGURATION_PROGRAM_WRITE_PASSWORD:
break;
case CONFIGURATION_PROGRAM_READ_PASSWORD:
break;
case CONFIGURATION_PROGRAM_CONFIGURATION_PASSWORD:
break;
case CONFIGURATION_RESET_WRITE_PASSWORD:
break;
case CONFIGURATION_RESET_READ_PASSWORD:
break;
case CONFIGURATION_PROGRAM_CONFIGURATION_REGISTERS:
m_state = STATE_WRITE_CONFIGURATION_REGISTERS;
m_byte = 0;
break;
case CONFIGURATION_READ_CONFIGURATION_REGISTERS:
m_state = STATE_READ_CONFIGURATION_REGISTERS;
m_byte = 0;
break;
case CONFIGURATION_MASS_PROGRAM:
break;
case CONFIGURATION_MASS_ERASE:
break;
default:
break;
}
}
}
void x76f041_device::load_address()
{
/* todo: handle other bcr bits */
int bcr;
m_address = m_shift;
verboselog( 1, "-> address: %02x\n", m_address );
if( ( m_command & 1 ) == 0 )
{
bcr = m_configuration_registers[ CONFIG_BCR1 ];
}
else
{
bcr = m_configuration_registers[ CONFIG_BCR2 ];
}
if( ( m_address & 0x80 ) != 0 )
{
bcr >>= 4;
}
if( ( ( m_command & 0xe0 ) == COMMAND_READ && ( bcr & BCR_Z ) != 0 && ( bcr & BCR_T ) != 0 ) ||
( ( m_command & 0xe0 ) == COMMAND_WRITE && ( bcr & BCR_Z ) != 0 ) )
{
/* todo: find out when this is really checked. */
verboselog( 1, "command not allowed\n" );
m_state = STATE_STOP;
m_sdar = 0;
}
else if( ( ( m_command & 0xe0 ) == COMMAND_WRITE && ( bcr & BCR_X ) == 0 ) ||
( ( m_command & 0xe0 ) == COMMAND_READ && ( bcr & BCR_Y ) == 0 ) )
{
verboselog( 1, "password not required\n" );
password_ok();
}
else
{
verboselog( 1, "send password\n" );
m_state = STATE_LOAD_PASSWORD;
m_byte = 0;
}
}
int x76f041_device::data_offset()
{
int block_offset = ( ( m_command & 1 ) << 8 ) + m_address;
// TODO: confirm block_start doesn't wrap.
return ( block_offset & 0x180 ) | ( ( block_offset + m_byte ) & 0x7f );
}
WRITE_LINE_MEMBER( x76f041_device::write_scl )
{
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 )
{
m_sdar = ( m_response_to_reset[ m_byte ] >> m_bit ) & 1;
verboselog( 2, "in response to reset %d (%d/%d)\n", m_sdar, m_byte, m_bit );
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_ADDRESS:
case STATE_LOAD_PASSWORD:
case STATE_VERIFY_PASSWORD:
case STATE_WRITE_DATA:
case STATE_WRITE_CONFIGURATION_REGISTERS:
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_ADDRESS;
break;
case STATE_LOAD_ADDRESS:
load_address();
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;
}
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 == 0xc0 )
{
/* todo: this should take 10ms before it returns ok. */
if( memcmp( password(), m_write_buffer, sizeof( m_write_buffer ) ) == 0 )
{
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 ) )
{
for( m_byte = 0; m_byte < sizeof( m_write_buffer ); m_byte++ )
{
int offset = data_offset();
verboselog( 1, "-> data[ %03x ]: %02x\n", offset, m_write_buffer[ m_byte ] );
m_data[ offset ] = m_write_buffer[ m_byte ];
}
m_byte = 0;
verboselog( 1, "data flushed\n" );
}
break;
case STATE_WRITE_CONFIGURATION_REGISTERS:
verboselog( 1, "-> configuration register[ %d ]: %02x\n", m_byte, m_shift );
/* todo: write after all bytes received? */
m_configuration_registers[ m_byte++ ] = m_shift;
if( m_byte == sizeof( m_configuration_registers ) )
{
m_byte = 0;
}
break;
}
m_bit = 0;
m_shift = 0;
}
}
break;
case STATE_READ_DATA:
case STATE_READ_CONFIGURATION_REGISTERS:
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();
m_shift = m_data[ offset ];
verboselog( 1, "<- data[ %03x ]: %02x\n", offset, m_shift );
break;
case STATE_READ_CONFIGURATION_REGISTERS:
offset = m_byte & 7;
m_shift = m_configuration_registers[ offset ];
verboselog( 1, "<- configuration register[ %d ]: %02x\n", offset, m_shift );
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;
}
WRITE_LINE_MEMBER( x76f041_device::write_sda )
{
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, "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;
}
READ_LINE_MEMBER( x76f041_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 x76f041_device::nvram_default()
{
m_response_to_reset[0] = 0x19;
m_response_to_reset[1] = 0x55;
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_configuration_password, 0, sizeof( m_configuration_password ) );
memset( m_configuration_registers, 0, sizeof( m_configuration_registers ) );
memset( m_data, 0, sizeof( m_data ) );
int expected_bytes = sizeof( m_response_to_reset ) + sizeof( m_write_password ) + sizeof( m_read_password ) +
sizeof( m_configuration_password ) + sizeof( m_configuration_registers ) + sizeof( m_data );
if( !m_region )
{
logerror( "x76f041(%s) region not found\n", tag() );
}
else if( m_region->bytes() != expected_bytes )
{
logerror( "x76f041(%s) region length 0x%x expected 0x%x\n", tag(), m_region->bytes(), expected_bytes );
}
else
{
UINT8 *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_configuration_password, region, sizeof( m_configuration_password ) ); region += sizeof( m_configuration_password );
memcpy( m_configuration_registers, region, sizeof( m_configuration_registers ) ); region += sizeof( m_configuration_registers );
memcpy( m_data, region, sizeof( m_data ) ); region += sizeof( m_data );
}
}
void x76f041_device::nvram_read( emu_file &file )
{
file.read( m_response_to_reset, sizeof( m_response_to_reset ) );
file.read( m_write_password, sizeof( m_write_password ) );
file.read( m_read_password, sizeof( m_read_password ) );
file.read( m_configuration_password, sizeof( m_configuration_password ) );
file.read( m_configuration_registers, sizeof( m_configuration_registers ) );
file.read( m_data, sizeof( m_data ) );
}
void x76f041_device::nvram_write( emu_file &file )
{
file.write( m_response_to_reset, sizeof( m_response_to_reset ) );
file.write( m_write_password, sizeof( m_write_password ) );
file.write( m_read_password, sizeof( m_read_password ) );
file.write( m_configuration_password, sizeof( m_configuration_password ) );
file.write( m_configuration_registers, sizeof( m_configuration_registers ) );
file.write( m_data, sizeof( m_data ) );
}