11 files changed, 880 insertions, 0 deletions

diff --git a/quantum/serial_link/protocol/byte_stuffer.c b/quantum/serial_link/protocol/byte_stuffer.c
new file mode 100644
index 000000000..2c87d64c2
--- /dev/null
+++ b/quantum/serial_link/protocol/byte_stuffer.c
@@ -0,0 +1,142 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "serial_link/protocol/byte_stuffer.h"
+#include "serial_link/protocol/frame_validator.h"
+#include "serial_link/protocol/physical.h"
+#include <stdbool.h>
+
+// This implements the "Consistent overhead byte stuffing protocol"
+// https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing
+// http://www.stuartcheshire.org/papers/COBSforToN.pdf
+
+typedef struct byte_stuffer_state {
+    uint16_t next_zero;
+    uint16_t data_pos;
+    bool long_frame;
+    uint8_t data[MAX_FRAME_SIZE];
+}byte_stuffer_state_t;
+
+static byte_stuffer_state_t states[NUM_LINKS];
+
+void init_byte_stuffer_state(byte_stuffer_state_t* state) {
+    state->next_zero = 0;
+    state->data_pos = 0;
+    state->long_frame = false;
+}
+
+void init_byte_stuffer(void) {
+    int i;
+    for (i=0;i<NUM_LINKS;i++) {
+        init_byte_stuffer_state(&states[i]);
+    }
+}
+
+void byte_stuffer_recv_byte(uint8_t link, uint8_t data) {
+    byte_stuffer_state_t* state = &states[link];
+    // Start of a new frame
+    if (state->next_zero == 0) {
+        state->next_zero = data;
+        state->long_frame = data == 0xFF;
+        state->data_pos = 0;
+        return;
+    }
+
+    state->next_zero--;
+    if (data == 0) {
+        if (state->next_zero == 0) {
+            // The frame is completed
+            if (state->data_pos > 0) {
+                validator_recv_frame(link, state->data, state->data_pos);
+            }
+        }
+        else {
+            // The frame is invalid, so reset
+            init_byte_stuffer_state(state);
+        }
+    }
+    else {
+        if (state->data_pos == MAX_FRAME_SIZE) {
+            // We exceeded our maximum frame size
+            // therefore there's nothing else to do than reset to a new frame
+            state->next_zero = data;
+            state->long_frame = data == 0xFF;
+            state->data_pos = 0;
+        }
+        else if (state->next_zero == 0) {
+            if (state->long_frame) {
+                // This is part of a long frame, so continue
+                state->next_zero = data;
+                state->long_frame = data == 0xFF;
+            }
+            else {
+                // Special case for zeroes
+                state->next_zero = data;
+                state->data[state->data_pos++] = 0;
+            }
+        }
+        else {
+            state->data[state->data_pos++] = data;
+        }
+    }
+}
+
+static void send_block(uint8_t link, uint8_t* start, uint8_t* end, uint8_t num_non_zero) {
+    send_data(link, &num_non_zero, 1);
+    if (end > start) {
+        send_data(link, start, end-start);
+    }
+}
+
+void byte_stuffer_send_frame(uint8_t link, uint8_t* data, uint16_t size) {
+    const uint8_t zero = 0;
+    if (size > 0) {
+        uint16_t num_non_zero = 1;
+        uint8_t* end = data + size;
+        uint8_t* start = data;
+        while (data < end) {
+            if (num_non_zero == 0xFF) {
+                // There's more data after big non-zero block
+                // So send it, and start a new block
+                send_block(link, start, data, num_non_zero);
+                start = data;
+                num_non_zero = 1;
+            }
+            else {
+                if (*data == 0) {
+                    // A zero encountered, so send the block
+                    send_block(link, start, data, num_non_zero);
+                    start = data + 1;
+                    num_non_zero = 1;
+                }
+                else {
+                    num_non_zero++;
+                }
+                ++data;
+            }
+        }
+        send_block(link, start, data, num_non_zero);
+        send_data(link, &zero, 1);
+    }
+}
diff --git a/quantum/serial_link/protocol/byte_stuffer.h b/quantum/serial_link/protocol/byte_stuffer.h
new file mode 100644
index 000000000..97e896856
--- /dev/null
+++ b/quantum/serial_link/protocol/byte_stuffer.h
@@ -0,0 +1,37 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_BYTE_STUFFER_H
+#define SERIAL_LINK_BYTE_STUFFER_H
+
+#include <stdint.h>
+
+#define MAX_FRAME_SIZE 1024
+#define NUM_LINKS 2
+
+void init_byte_stuffer(void);
+void byte_stuffer_recv_byte(uint8_t link, uint8_t data);
+void byte_stuffer_send_frame(uint8_t link, uint8_t* data, uint16_t size);
+
+#endif
diff --git a/quantum/serial_link/protocol/frame_router.c b/quantum/serial_link/protocol/frame_router.c
new file mode 100644
index 000000000..04b8c2e75
--- /dev/null
+++ b/quantum/serial_link/protocol/frame_router.c
@@ -0,0 +1,69 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "serial_link/protocol/frame_router.h"
+#include "serial_link/protocol/transport.h"
+#include "serial_link/protocol/frame_validator.h"
+
+static bool is_master;
+
+void router_set_master(bool master) {
+   is_master = master;
+}
+
+void route_incoming_frame(uint8_t link, uint8_t* data, uint16_t size){
+    if (is_master) {
+        if (link == DOWN_LINK) {
+            transport_recv_frame(data[size-1], data, size - 1);
+        }
+    }
+    else {
+        if (link == UP_LINK) {
+            if (data[size-1] & 1) {
+                transport_recv_frame(0, data, size - 1);
+            }
+            data[size-1] >>= 1;
+            validator_send_frame(DOWN_LINK, data, size);
+        }
+        else {
+            data[size-1]++;
+            validator_send_frame(UP_LINK, data, size);
+        }
+    }
+}
+
+void router_send_frame(uint8_t destination, uint8_t* data, uint16_t size) {
+    if (destination == 0) {
+        if (!is_master) {
+            data[size] = 1;
+            validator_send_frame(UP_LINK, data, size + 1);
+        }
+    }
+    else {
+        if (is_master) {
+            data[size] = destination;
+            validator_send_frame(DOWN_LINK, data, size + 1);
+        }
+    }
+}
diff --git a/quantum/serial_link/protocol/frame_router.h b/quantum/serial_link/protocol/frame_router.h
new file mode 100644
index 000000000..712250ff3
--- /dev/null
+++ b/quantum/serial_link/protocol/frame_router.h
@@ -0,0 +1,38 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_FRAME_ROUTER_H
+#define SERIAL_LINK_FRAME_ROUTER_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define UP_LINK 0
+#define DOWN_LINK 1
+
+void router_set_master(bool master);
+void route_incoming_frame(uint8_t link, uint8_t* data, uint16_t size);
+void router_send_frame(uint8_t destination, uint8_t* data, uint16_t size);
+
+#endif
diff --git a/quantum/serial_link/protocol/frame_validator.c b/quantum/serial_link/protocol/frame_validator.c
new file mode 100644
index 000000000..474f80ee8
--- /dev/null
+++ b/quantum/serial_link/protocol/frame_validator.c
@@ -0,0 +1,121 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "serial_link/protocol/frame_validator.h"
+#include "serial_link/protocol/frame_router.h"
+#include "serial_link/protocol/byte_stuffer.h"
+#include <string.h>
+
+const uint32_t poly8_lookup[256] =
+{
+ 0, 0x77073096, 0xEE0E612C, 0x990951BA,
+ 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
+ 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
+ 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
+ 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
+ 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+ 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
+ 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
+ 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
+ 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
+ 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
+ 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+ 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
+ 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+ 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
+ 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
+ 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
+ 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+ 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
+ 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
+ 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
+ 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
+ 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
+ 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+ 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
+ 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
+ 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
+ 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
+ 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
+ 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+ 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
+ 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
+ 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
+ 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
+ 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
+ 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+ 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
+ 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
+ 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+ 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
+ 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
+ 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+ 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
+ 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
+ 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
+ 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+ 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
+ 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+ 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
+ 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
+ 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
+ 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
+ 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
+ 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+ 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
+ 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
+ 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
+ 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
+ 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
+ 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+ 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
+ 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+ 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
+ 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
+};
+
+static uint32_t crc32_byte(uint8_t *p, uint32_t bytelength)
+{
+    uint32_t crc = 0xffffffff;
+    while (bytelength-- !=0) crc = poly8_lookup[((uint8_t) crc ^ *(p++))] ^ (crc >> 8);
+    // return (~crc); also works
+    return (crc ^ 0xffffffff);
+}
+
+void validator_recv_frame(uint8_t link, uint8_t* data, uint16_t size) {
+    if (size > 4) {
+        uint32_t frame_crc;
+        memcpy(&frame_crc, data + size -4, 4);
+        uint32_t expected_crc = crc32_byte(data, size - 4);
+        if (frame_crc == expected_crc) {
+            route_incoming_frame(link, data, size-4);
+        }
+    }
+}
+
+void validator_send_frame(uint8_t link, uint8_t* data, uint16_t size) {
+    uint32_t crc = crc32_byte(data, size);
+    memcpy(data + size, &crc, 4);
+    byte_stuffer_send_frame(link, data, size + 4);
+}
diff --git a/quantum/serial_link/protocol/frame_validator.h b/quantum/serial_link/protocol/frame_validator.h
new file mode 100644
index 000000000..4a910d510
--- /dev/null
+++ b/quantum/serial_link/protocol/frame_validator.h
@@ -0,0 +1,34 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_FRAME_VALIDATOR_H
+#define SERIAL_LINK_FRAME_VALIDATOR_H
+
+#include <stdint.h>
+
+void validator_recv_frame(uint8_t link, uint8_t* data, uint16_t size);
+// The buffer pointed to by the data needs 4 additional bytes
+void validator_send_frame(uint8_t link, uint8_t* data, uint16_t size);
+
+#endif
diff --git a/quantum/serial_link/protocol/physical.h b/quantum/serial_link/protocol/physical.h
new file mode 100644
index 000000000..425e06cdd
--- /dev/null
+++ b/quantum/serial_link/protocol/physical.h
@@ -0,0 +1,30 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_PHYSICAL_H
+#define SERIAL_LINK_PHYSICAL_H
+
+void send_data(uint8_t link, const uint8_t* data, uint16_t size);
+
+#endif
diff --git a/quantum/serial_link/protocol/transport.c b/quantum/serial_link/protocol/transport.c
new file mode 100644
index 000000000..ff795fe20
--- /dev/null
+++ b/quantum/serial_link/protocol/transport.c
@@ -0,0 +1,128 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "serial_link/protocol/transport.h"
+#include "serial_link/protocol/frame_router.h"
+#include "serial_link/protocol/triple_buffered_object.h"
+#include <string.h>
+
+#define MAX_REMOTE_OBJECTS 16
+static remote_object_t* remote_objects[MAX_REMOTE_OBJECTS];
+static uint32_t num_remote_objects = 0;
+
+void reinitialize_serial_link_transport(void) {
+    num_remote_objects = 0;
+}
+
+void add_remote_objects(remote_object_t** _remote_objects, uint32_t _num_remote_objects) {
+    unsigned int i;
+    for(i=0;i<_num_remote_objects;i++) {
+        remote_object_t* obj = _remote_objects[i];
+        remote_objects[num_remote_objects++] = obj;
+        if (obj->object_type == MASTER_TO_ALL_SLAVES) {
+            triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer;
+            triple_buffer_init(tb);
+            uint8_t* start = obj->buffer + LOCAL_OBJECT_SIZE(obj->object_size);
+            tb = (triple_buffer_object_t*)start;
+            triple_buffer_init(tb);
+        }
+        else if(obj->object_type == MASTER_TO_SINGLE_SLAVE) {
+            uint8_t* start = obj->buffer;
+            unsigned int j;
+            for (j=0;j<NUM_SLAVES;j++) {
+                triple_buffer_object_t* tb = (triple_buffer_object_t*)start;
+                triple_buffer_init(tb);
+                start += LOCAL_OBJECT_SIZE(obj->object_size);
+            }
+            triple_buffer_object_t* tb = (triple_buffer_object_t*)start;
+            triple_buffer_init(tb);
+        }
+        else {
+            uint8_t* start = obj->buffer;
+            triple_buffer_object_t* tb = (triple_buffer_object_t*)start;
+            triple_buffer_init(tb);
+            start += LOCAL_OBJECT_SIZE(obj->object_size);
+            unsigned int j;
+            for (j=0;j<NUM_SLAVES;j++) {
+                tb = (triple_buffer_object_t*)start;
+                triple_buffer_init(tb);
+                start += REMOTE_OBJECT_SIZE(obj->object_size);
+            }
+        }
+    }
+}
+
+void transport_recv_frame(uint8_t from, uint8_t* data, uint16_t size) {
+    uint8_t id = data[size-1];
+    if (id < num_remote_objects) {
+        remote_object_t* obj = remote_objects[id];
+        if (obj->object_size == size - 1) {
+            uint8_t* start;
+            if (obj->object_type == MASTER_TO_ALL_SLAVES) {
+                start = obj->buffer + LOCAL_OBJECT_SIZE(obj->object_size);
+            }
+            else if(obj->object_type == SLAVE_TO_MASTER) {
+                start = obj->buffer + LOCAL_OBJECT_SIZE(obj->object_size);
+                start += (from - 1) * REMOTE_OBJECT_SIZE(obj->object_size);
+            }
+            else {
+                start = obj->buffer + NUM_SLAVES * LOCAL_OBJECT_SIZE(obj->object_size);
+            }
+            triple_buffer_object_t* tb = (triple_buffer_object_t*)start;
+            void* ptr = triple_buffer_begin_write_internal(obj->object_size, tb);
+            memcpy(ptr, data, size - 1);
+            triple_buffer_end_write_internal(tb);
+        }
+    }
+}
+
+void update_transport(void) {
+    unsigned int i;
+    for(i=0;i<num_remote_objects;i++) {
+        remote_object_t* obj = remote_objects[i];
+        if (obj->object_type == MASTER_TO_ALL_SLAVES || obj->object_type == SLAVE_TO_MASTER) {
+            triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer;
+            uint8_t* ptr = (uint8_t*)triple_buffer_read_internal(obj->object_size + LOCAL_OBJECT_EXTRA, tb);
+            if (ptr) {
+                ptr[obj->object_size] = i;
+                uint8_t dest = obj->object_type == MASTER_TO_ALL_SLAVES ? 0xFF : 0;
+                router_send_frame(dest, ptr, obj->object_size + 1);
+            }
+        }
+        else {
+            uint8_t* start = obj->buffer;
+            unsigned int j;
+            for (j=0;j<NUM_SLAVES;j++) {
+                triple_buffer_object_t* tb = (triple_buffer_object_t*)start;
+                uint8_t* ptr = (uint8_t*)triple_buffer_read_internal(obj->object_size + LOCAL_OBJECT_EXTRA, tb);
+                if (ptr) {
+                    ptr[obj->object_size] = i;
+                    uint8_t dest = j + 1;
+                    router_send_frame(dest, ptr, obj->object_size + 1);
+                }
+                start += LOCAL_OBJECT_SIZE(obj->object_size);
+            }
+        }
+    }
+}
diff --git a/quantum/serial_link/protocol/transport.h b/quantum/serial_link/protocol/transport.h
new file mode 100644
index 000000000..2c5d890b2
--- /dev/null
+++ b/quantum/serial_link/protocol/transport.h
@@ -0,0 +1,152 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_TRANSPORT_H
+#define SERIAL_LINK_TRANSPORT_H
+
+#include "serial_link/protocol/triple_buffered_object.h"
+#include "serial_link/system/serial_link.h"
+
+#define NUM_SLAVES 8
+#define LOCAL_OBJECT_EXTRA 16
+
+// master -> slave = 1 local(target all), 1 remote object
+// slave -> master = 1 local(target 0), multiple remote objects
+// master -> single slave (multiple local, target id), 1 remote object
+typedef enum {
+    MASTER_TO_ALL_SLAVES,
+    MASTER_TO_SINGLE_SLAVE,
+    SLAVE_TO_MASTER,
+} remote_object_type;
+
+typedef struct {
+    remote_object_type object_type;
+    uint16_t object_size;
+    uint8_t buffer[] __attribute__((aligned(4)));
+} remote_object_t;
+
+#define REMOTE_OBJECT_SIZE(objectsize) \
+    (sizeof(triple_buffer_object_t) + objectsize * 3)
+#define LOCAL_OBJECT_SIZE(objectsize) \
+    (sizeof(triple_buffer_object_t) + (objectsize + LOCAL_OBJECT_EXTRA) * 3)
+
+#define REMOTE_OBJECT_HELPER(name, type, num_local, num_remote) \
+typedef struct { \
+    remote_object_t object; \
+    uint8_t buffer[ \
+        num_remote * REMOTE_OBJECT_SIZE(sizeof(type)) + \
+        num_local * LOCAL_OBJECT_SIZE(sizeof(type))]; \
+} remote_object_##name##_t;
+
+#define MASTER_TO_ALL_SLAVES_OBJECT(name, type) \
+    REMOTE_OBJECT_HELPER(name, type, 1, 1) \
+    remote_object_##name##_t remote_object_##name = { \
+        .object = { \
+            .object_type = MASTER_TO_ALL_SLAVES, \
+            .object_size = sizeof(type), \
+        } \
+    }; \
+    type* begin_write_##name(void) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer; \
+        return (type*)triple_buffer_begin_write_internal(sizeof(type) + LOCAL_OBJECT_EXTRA, tb); \
+    }\
+    void end_write_##name(void) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer; \
+        triple_buffer_end_write_internal(tb); \
+        signal_data_written(); \
+    }\
+    type* read_##name(void) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        uint8_t* start = obj->buffer + LOCAL_OBJECT_SIZE(obj->object_size);\
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)start; \
+        return (type*)triple_buffer_read_internal(obj->object_size, tb); \
+    }
+
+#define MASTER_TO_SINGLE_SLAVE_OBJECT(name, type) \
+    REMOTE_OBJECT_HELPER(name, type, NUM_SLAVES, 1) \
+    remote_object_##name##_t remote_object_##name = { \
+        .object = { \
+            .object_type = MASTER_TO_SINGLE_SLAVE, \
+            .object_size = sizeof(type), \
+        } \
+    }; \
+    type* begin_write_##name(uint8_t slave) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        uint8_t* start = obj->buffer;\
+        start += slave * LOCAL_OBJECT_SIZE(obj->object_size); \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)start; \
+        return (type*)triple_buffer_begin_write_internal(sizeof(type) + LOCAL_OBJECT_EXTRA, tb); \
+    }\
+    void end_write_##name(uint8_t slave) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        uint8_t* start = obj->buffer;\
+        start += slave * LOCAL_OBJECT_SIZE(obj->object_size); \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)start; \
+        triple_buffer_end_write_internal(tb); \
+        signal_data_written(); \
+    }\
+    type* read_##name() { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        uint8_t* start = obj->buffer + NUM_SLAVES * LOCAL_OBJECT_SIZE(obj->object_size);\
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)start; \
+        return (type*)triple_buffer_read_internal(obj->object_size, tb); \
+    }
+
+#define SLAVE_TO_MASTER_OBJECT(name, type) \
+    REMOTE_OBJECT_HELPER(name, type, 1, NUM_SLAVES) \
+    remote_object_##name##_t remote_object_##name = { \
+        .object = { \
+            .object_type = SLAVE_TO_MASTER, \
+            .object_size = sizeof(type), \
+        } \
+    }; \
+    type* begin_write_##name(void) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer; \
+        return (type*)triple_buffer_begin_write_internal(sizeof(type) + LOCAL_OBJECT_EXTRA, tb); \
+    }\
+    void end_write_##name(void) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)obj->buffer; \
+        triple_buffer_end_write_internal(tb); \
+        signal_data_written(); \
+    }\
+    type* read_##name(uint8_t slave) { \
+        remote_object_t* obj = (remote_object_t*)&remote_object_##name; \
+        uint8_t* start = obj->buffer + LOCAL_OBJECT_SIZE(obj->object_size);\
+        start+=slave * REMOTE_OBJECT_SIZE(obj->object_size); \
+        triple_buffer_object_t* tb = (triple_buffer_object_t*)start; \
+        return (type*)triple_buffer_read_internal(obj->object_size, tb); \
+    }
+
+#define REMOTE_OBJECT(name) (remote_object_t*)&remote_object_##name
+
+void add_remote_objects(remote_object_t** remote_objects, uint32_t num_remote_objects);
+void reinitialize_serial_link_transport(void);
+void transport_recv_frame(uint8_t from, uint8_t* data, uint16_t size);
+void update_transport(void);
+
+#endif
diff --git a/quantum/serial_link/protocol/triple_buffered_object.c b/quantum/serial_link/protocol/triple_buffered_object.c
new file mode 100644
index 000000000..e3e8989d3
--- /dev/null
+++ b/quantum/serial_link/protocol/triple_buffered_object.c
@@ -0,0 +1,78 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "serial_link/protocol/triple_buffered_object.h"
+#include "serial_link/system/serial_link.h"
+#include <stdbool.h>
+#include <stddef.h>
+
+#define GET_READ_INDEX() object->state & 3
+#define GET_WRITE_INDEX() (object->state >> 2) & 3
+#define GET_SHARED_INDEX() (object->state >> 4) & 3
+#define GET_DATA_AVAILABLE() (object->state >> 6) & 1
+
+#define SET_READ_INDEX(i) object->state = ((object->state & ~3) | i)
+#define SET_WRITE_INDEX(i) object->state = ((object->state & ~(3 << 2)) | (i << 2))
+#define SET_SHARED_INDEX(i) object->state = ((object->state & ~(3 << 4)) | (i << 4))
+#define SET_DATA_AVAILABLE(i) object->state = ((object->state & ~(1 << 6)) | (i << 6))
+
+void triple_buffer_init(triple_buffer_object_t* object) {
+    object->state = 0;
+    SET_WRITE_INDEX(0);
+    SET_READ_INDEX(1);
+    SET_SHARED_INDEX(2);
+    SET_DATA_AVAILABLE(0);
+}
+
+void* triple_buffer_read_internal(uint16_t object_size, triple_buffer_object_t* object) {
+    serial_link_lock();
+    if (GET_DATA_AVAILABLE()) {
+        uint8_t shared_index = GET_SHARED_INDEX();
+        uint8_t read_index = GET_READ_INDEX();
+        SET_READ_INDEX(shared_index);
+        SET_SHARED_INDEX(read_index);
+        SET_DATA_AVAILABLE(false);
+        serial_link_unlock();
+        return object->buffer + object_size * shared_index;
+    }
+    else {
+        serial_link_unlock();
+        return NULL;
+    }
+}
+
+void* triple_buffer_begin_write_internal(uint16_t object_size, triple_buffer_object_t* object) {
+    uint8_t write_index = GET_WRITE_INDEX();
+    return object->buffer + object_size * write_index;
+}
+
+void triple_buffer_end_write_internal(triple_buffer_object_t* object) {
+    serial_link_lock();
+    uint8_t shared_index = GET_SHARED_INDEX();
+    uint8_t write_index = GET_WRITE_INDEX();
+    SET_SHARED_INDEX(write_index);
+    SET_WRITE_INDEX(shared_index);
+    SET_DATA_AVAILABLE(true);
+    serial_link_unlock();
+}
diff --git a/quantum/serial_link/protocol/triple_buffered_object.h b/quantum/serial_link/protocol/triple_buffered_object.h
new file mode 100644
index 000000000..2e57db3f5
--- /dev/null
+++ b/quantum/serial_link/protocol/triple_buffered_object.h
@@ -0,0 +1,51 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Fred Sundvik
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#ifndef SERIAL_LINK_TRIPLE_BUFFERED_OBJECT_H
+#define SERIAL_LINK_TRIPLE_BUFFERED_OBJECT_H
+
+#include <stdint.h>
+
+typedef struct {
+    uint8_t state;
+    uint8_t buffer[] __attribute__((aligned(4)));
+}triple_buffer_object_t;
+
+void triple_buffer_init(triple_buffer_object_t* object);
+
+#define triple_buffer_begin_write(object) \
+    (typeof(*object.buffer[0])*)triple_buffer_begin_write_internal(sizeof(*object.buffer[0]), (triple_buffer_object_t*)object)
+
+#define triple_buffer_end_write(object) \
+    triple_buffer_end_write_internal((triple_buffer_object_t*)object)
+
+#define triple_buffer_read(object) \
+    (typeof(*object.buffer[0])*)triple_buffer_read_internal(sizeof(*object.buffer[0]), (triple_buffer_object_t*)object)
+
+void* triple_buffer_begin_write_internal(uint16_t object_size, triple_buffer_object_t* object);
+void triple_buffer_end_write_internal(triple_buffer_object_t* object);
+void* triple_buffer_read_internal(uint16_t object_size, triple_buffer_object_t* object);
+
+
+#endif