Simple network device - netcard

.github/workflows/build.yml

@@ -18,6 +18,11 @@ jobs:
         curl -L -o libpcut.deb https://github.com/vhotspur/pcut/releases/download/v0.0.1/libpcut_0.0.1_amd64.deb
         sudo apt-get install ./libpcut.deb
 
+        sudo wget "https://d3s.mff.cuni.cz/f/teaching/nswi200/202526/pkg/ubuntu-24.04/mffd3s-binutils-riscv32-unknown-elf_2.45_amd64.deb"
+        sudo apt-get install ./mffd3s-binutils-riscv32-unknown-elf_2.45_amd64.deb
+        sudo wget "https://d3s.mff.cuni.cz/f/teaching/nswi200/202526/pkg/ubuntu-24.04/mffd3s-gcc-riscv32-unknown-elf_15.2.0_amd64.deb"
+        sudo apt-get install ./mffd3s-gcc-riscv32-unknown-elf_15.2.0_amd64.deb
+
     - name: configure
       run: ./configure
 

Makefile.in

@@ -37,6 +37,7 @@ distclean: clean
 test:
 	make -C . rvtest
 	bats tests/system/
+	make -C tests/devices test
 
 rvtest:
 	@echo "\nUnit tests:"

doc/reference/devices.rst

@@ -1019,3 +1019,118 @@ Commands
     Print a help on the command specified or a list of available commands.
 ``info``
     Print configuration information (number of columns, number of rows, assigned register address).
+
+
+
+
+Network card device ``dnetcard``
+-----------------------------------
+
+The device simulates a network card that has ability to send and receive packets
+using DMA for data transfers between the card and memory.
+
+Network card has optional logs which can be turned on using `verbose` variable: ``set verbose``.
+This helps to detect some mistakes as connection failure with TCP.
+
+Both DMA buffers have size of 1500, because that is a common MTU.
+
+Supported protocols are UDP and simplified TCP. UDP protocol is fully supported.
+Simplified TCP means, that the device sends only TCP data packets to/from the guest.
+If the guest initiates a connection by sending a packet to a new address,
+the device starts a connection which can be used to transfer the data.
+If the connection can not be established, then both TX and ERR interrupts are raised signaling an error with sending packet.
+Other features of the TCP protocol are not supported.
+
+Initialization parameters: ``address`` ``intno``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+``address``
+   Physical address of the networking card register.
+``intno``
+   DMA Interrupt number.
+
+Registers
+^^^^^^^^^
+
+.. csv-table:: ``dnetcard`` programming registers
+   :header: Offset, Size, Name, Operation, Description
+   :widths: auto
+
+    "+0",4,"TX buffer address (lower 32 bits)",read,"Get the current physical address of the TX DMA buffer (lower 32 bits)"
+    ,,,write,"Set the physical address of the TX DMA buffer (lower 32 bits)
+
+    * performing a send operation will send IP packet stored in this buffer
+    "
+    "+4",4,"TX buffer address (higher 4 bits)","read/write","Higher 4 bits for TX DMA physical address. See description of TX buffer address (lower 32 bits) for further details."
+    "+8",4,"RX buffer address (lower 32 bits)",read,"Get the current physical address of the RX DMA buffer (lower 32 bits)"
+    ,,,write,"Set the physical address of the RX DMA buffer (lower 32 bits)
+
+    * performing a receive operationg will receive incoming IP packet into this buffer
+    * writing to this buffer while receiving is enabled results in an error
+    "
+    "+12",4,"RX buffer address (higher 4 bits)","read/write","Higher 4 bits for RX DMA physical address. See description of RX buffer address (lower 32 bits) for further details."
+    "+16",4,"status/command",read,"
+    Get a bitfield representing the current status of the device:
+
+    .. csv-table::
+        :header: 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5,4,3,2,1,0
+
+        r1,e_i,rx_i,tx_i,rec,r0
+
+    ``r0``, ``r1``
+        (reserved)
+    ``e_i``
+        0: no error
+
+        1: error interrupt pending because the previous operation cause an error
+
+        when combined with tx_i: dnetcard could not send IP packet (used in simplified TCP)
+    ``rx_i``
+        0: no error
+
+        1: rx interrupt pending because received packet in RX buffer
+
+        data receiving is set off so that new RX address can be set
+    ``tx_i``
+        0: no error
+
+        1: tx interrupt pending because finished sending packet from TX buffer
+    ``rec``
+        0: dnetcard does not receive any data
+
+        1: dnetcard is ready for receiving
+    "
+    ,,,write,"
+    Set a bitfield representing requested operation:
+
+    .. csv-table::
+        :header: 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5,4,3,2,1,0
+
+        r0,e_ack,rx_ack,tx_ack,rec,s
+
+    ``r0``
+        (reserved)
+    ``e_ack``
+        if set to 1 then the error interrupt is deasserted
+    ``rx_ack``
+        if set to 1 then the rx interrupt is deasserted
+    ``tx_ack``
+        if set to 1 then the tx interrupt is deasserted
+    ``rec``
+        if set to 1 then dnetcard receving is switched (on/off depeding on previous state)
+    ``s``
+        if set to 1 then a send operation is initiated (reading the data from TX DMA buffer)
+    "
+    "+20",4,"IP address","read/write","IP address assigned to the device by the guest. It must be set before the device can be used. This address must be used in outgoing packets and will be used in incoming packets."
+
+Commands
+^^^^^^^^
+
+``help [cmd]``
+   Print a help on the command specified or a list of available commands.
+``info``
+   Print the device information.
+``stat``
+   Print device statistics.
+``listen <port> <protocol - STCP or UDP> [<visibility - local (default) or public>]``
+   Listen on port with specified protocol. If listenning locally (default), MSIM listens on localhost. If listenning publicly, MSIM listens on some IP address of the host.

doc/reference/internal_variables.rst

@@ -9,6 +9,8 @@ Following internal variables are available:
 
 ``trace``
    Enable trace mode
+``verbose``
+   Enable verbose mode for devices e.g. dnetcard
 ``iaddr``
    Enable addresses in disassembler
 ``iopc``

src/Makefile.in

@@ -56,6 +56,7 @@ SOURCES = \
 	device/dcycle.c \
 	device/dkeyboard.c \
 	device/dlcd.c \
+	device/dnetcard.c \
 	device/dnomem.c \
 	device/dorder.c \
 	device/dprinter.c \

src/device/device.c

@@ -28,6 +28,7 @@
 #include "device.h"
 #include "dkeyboard.h"
 #include "dlcd.h"
+#include "dnetcard.h"
 #include "dnomem.h"
 #include "dorder.h"
 #include "dprinter.h"
@@ -42,7 +43,7 @@
 #undef XLEN
 
 /** Count of device types */
-#define DEVICE_TYPE_COUNT 13
+#define DEVICE_TYPE_COUNT 14
 
 /* Implemented peripheral list */
 const device_type_t *device_types[DEVICE_TYPE_COUNT] = {
@@ -58,7 +59,8 @@ const device_type_t *device_types[DEVICE_TYPE_COUNT] = {
     &dnomem,
     &ddisk,
     &dtime,
-    &dlcd
+    &dlcd,
+    &dnetcard
 };
 
 /* List of all devices */