Hi,
There are a few things I do not understand about this addition. I brief review
of the code seems OK but I am struggling to understand the requirements driving
this addition. Can a ticket please be created with the requirements and a real
world use case of how it would be used and what problem(s) it solves?
I also think dev/io.h and dev/iopacket.c are too generic for something thing
that appears to be specific to a specific use case.
Chris
On 15/1/2024 8:45 pm, Sebastian Huber wrote:
> The I/O packet processor provides a simple mechanism to exchange
> reliable and in-order data through transmitting and receiving one
> character at a time.
>
> The I/O packet processor does not buffer data. The processor uses a
> stop-and-wait automatic repeat request method. There is at most one packet
> in transmission. The data transfer is done using a single character input
> and output method. The protocol uses 12-bit sequence numbers, so a host
> could use a sliding window method to increase throughput. All integers and
> data are base64url encoded. A 24-bit CRC is used to ensure the data
> integrity. The '{' character starts a packet. The '}' character terminates
> a packet. The '#' character prefixes a 24-bit CRC value. The ':' character
> separates fields. The '+' character prefixes data fields. The following
> packets are defined:
>
> * hello: {<12-bit seq><12-bit ack>:H#<24-bit CRC>}
>
> * acknowledge: {<12-bit seq><12-bit ack>:A#<24-bit CRC>}
>
> * reject: {<12-bit seq><12-bit ack>
> :R:<12-bit seq of rejected packet>#<24-bit CRC>}
>
> * jump: {<12-bit seq><12-bit ack>:J:<64-bit address>#<24-bit CRC>}
>
> * load: {<12-bit seq><12-bit ack>:L:<64-bit load address>
> <64-bit load size in bytes>#<24-bit CRC>+<data to load>#<24-bit CRC>}
>
> * signal: {<12-bit seq><12-bit ack>:S:<64-bit signal number>:
> <64-bit signal value>#<24-bit CRC>}
>
> * channel: {<12-bit seq><12-bit ack>:C:<64-bit channel number>
> <64-bit data size in bytes>#<24-bit CRC>+<channel data>#<24-bit CRC>}
>
> The intended use case are boot loaders and test runners. For example, test
> runners may interface with an external test server performing equipment
> handling on request using the I/O packet processor.
>
> Use _IO_Packet_initialize() to initialize the I/O packet processor. Use
> _IO_Packet_process() to drive the packet processing. You can enqueue
> packets for transmission with _IO_Packet_enqueue(). You can reliably send
> signals with _IO_Packet_send(). You can reliably transmit and receive
> channel data with _IO_Packet_channel_push() and
> _IO_Packet_channel_exchange().
>
> A simple boot loader could be implemented like this:
>
> #include <bsp.h>
> #include <rtems/bspIo.h>
> #include <rtems/counter.h>
> #include <rtems/dev/io.h>
>
> static void output_char( IO_Packet_control *self, uint8_t ch )
> {
> (void) self;
> rtems_putc( ch );
> }
>
> static IO_Packet_status event_handler(
> IO_Packet_control *self,
> IO_Packet_event_control *ctrl,
> IO_Packet_event evt
> )
> {
> (void) ctrl;
>
> switch ( evt ) {
> case IO_PACKET_EVENT_JUMP:
> _IO_Packet_send_acknowledge( self );
> bsp_restart( _IO_Packet_get_jump_address( self ) );
> break;
> case IO_PACKET_EVENT_LOAD_END:
> _IO_Packet_send_acknowledge( self );
> break;
> case IO_PACKET_EVENT_OUTPUT_END:
> rtems_putc( '\n' );
> break;
> default:
> break;
> }
>
> return IO_PACKET_SUCCESSFUL;
> }
>
> static uint32_t clock_monotonic( IO_Packet_control *self )
> {
> (void) self;
> return rtems_counter_read();
> }
>
> static void Init( rtems_task_argument arg )
> {
> IO_Packet_control self;
> IO_Packet_event_control event;
>
> (void) arg;
> _IO_Packet_initialize( &self, 0, NULL, output_char, clock_monotonic );
> _IO_Packet_prepend_event_handler( &self, &event, event_handler );
>
> while ( true ) {
> _IO_Packet_process( &self, getchark() );
> }
> }
>
> Matthew Joyce (1):
> dev/io: Add base64 decoder
>
> Sebastian Huber (3):
> dev/io: Make base64 encoding tables public
> dev/io: Add a CRC-24Q implementation
> dev/io: Add packet processor
>
> cpukit/dev/iobase64.c | 24 +-
> cpukit/dev/iobase64decode.c | 166 +++
> cpukit/dev/iocrc24q.c | 148 +++
> cpukit/dev/iopacket.c | 837 ++++++++++++++++
> cpukit/include/rtems/dev/io.h | 941 ++++++++++++++++++
> spec/build/cpukit/librtemscpu.yml | 3 +
> .../build/testsuites/unit/unit-no-clock-0.yml | 3 +
> testsuites/unit/tc-io-base64-decode.c | 180 ++++
> testsuites/unit/tc-io-packet.c | 617 ++++++++++++
> 9 files changed, 2912 insertions(+), 7 deletions(-)
> create mode 100644 cpukit/dev/iobase64decode.c
> create mode 100644 cpukit/dev/iocrc24q.c
> create mode 100644 cpukit/dev/iopacket.c
> create mode 100644 testsuites/unit/tc-io-base64-decode.c
> create mode 100644 testsuites/unit/tc-io-packet.c
>
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