kind of works for writing flash. IMPORTANT ISSUE - the memory usage output given by the linker for program size used DOES NOT equal the actual flash space used when programming. INVESTIGATE: did I set a memory space that doesn't lie on a page boundary? or do I just need to increase the flash space allocated to the bootloader

bootloader/clubdance_v2_bootloader.X/nbproject/configurations.xml

@@ -20,6 +20,7 @@
         </logicalFolder>
       </logicalFolder>
       <itemPath>../../common_src/system.c</itemPath>
+      <itemPath>../../common_src/memory.h</itemPath>
     </logicalFolder>
     <logicalFolder name="HeaderFiles"
                    displayName="Header Files"
@@ -38,6 +39,7 @@
       <itemPath>../src/usb_events.c</itemPath>
       <itemPath>../src/main.c</itemPath>
       <itemPath>../src/bootloader.c</itemPath>
+      <itemPath>../src/VectorRemap.asm</itemPath>
     </logicalFolder>
     <logicalFolder name="ExternalFiles"
                    displayName="Important Files"
@@ -140,10 +142,10 @@
         <property key="code-model-rom" value="default,-1C00-7FFF"/>
         <property key="create-html-files" value="false"/>
         <property key="data-model-ram" value=""/>
-        <property key="data-model-size-of-double" value="24"/>
+        <property key="data-model-size-of-double" value="32"/>
-        <property key="data-model-size-of-double-gcc" value="short-double"/>
+        <property key="data-model-size-of-double-gcc" value="no-short-double"/>
-        <property key="data-model-size-of-float" value="24"/>
+        <property key="data-model-size-of-float" value="32"/>
-        <property key="data-model-size-of-float-gcc" value="short-float"/>
+        <property key="data-model-size-of-float-gcc" value="no-short-float"/>
         <property key="display-class-usage" value="false"/>
         <property key="display-hex-usage" value="false"/>
         <property key="display-overall-usage" value="true"/>
@@ -178,6 +180,7 @@
                   value="Press to browse for a specific firmware version"/>
         <property key="ToolFirmwareOption.UseLatestFirmware" value="true"/>
         <property key="debugoptions.useswbreakpoints" value="false"/>
+        <property key="firmware.download.all" value="false"/>
         <property key="hwtoolclock.frcindebug" value="false"/>
         <property key="memories.aux" value="false"/>
         <property key="memories.bootflash" value="true"/>

bootloader/src/VectorRemap.asm

@@ -0,0 +1,35 @@
+;/*******************************************************************************
+;Copyright 2016 Microchip Technology Inc. (www.microchip.com)
+;
+;Licensed under the Apache License, Version 2.0 (the "License");
+;you may not use this file except in compliance with the License.
+;You may obtain a copy of the License at
+;
+;    http://www.apache.org/licenses/LICENSE-2.0
+;
+;Unless required by applicable law or agreed to in writing, software
+;distributed under the License is distributed on an "AS IS" BASIS,
+;WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;See the License for the specific language governing permissions and
+;limitations under the License.
+;
+;To request to license the code under the MLA license (www.microchip.com/mla_license), 
+;please contact mla_licensing@microchip.com
+;*******************************************************************************/
+
+    ;//High priority interrupt vector remapping
+    PSECT HiVector,class=CODE,delta=1,abs
+    org 0x08
+    goto 0x1C08     ;Resides at 0x0008 (hardware high priority interrupt vector), and causes PC to jump to 0x1C08 upon a high priority interrupt event
+
+
+    ;//Low priority interrupt vector remapping, as well as bootloader mode absolute
+    ;//entry point (located at 0x001C).
+    PSECT LoVector,class=CODE,delta=1,abs
+    org	    0x18
+    goto    0x1C18  ;Resides at 0x0018 (hardware low priority interrupt vector), and causes PC to jump to 0x1C18 upon a low priority interrupt event
+    goto    0x30    ;Resides at 0x001C  //Serves as absolute entry point from application program into the bootloader mode
+
+
+
+    end

bootloader/src/bootloader.c

@@ -152,8 +152,8 @@ unsigned char BufferedDataIndex;
 uint24_t ProgrammedPointer;
 unsigned char ConfigsLockValue;
 
-USB_VOLATILE USB_HANDLE txHandle = 0;
+USB_VOLATILE USB_HANDLE txHandle;
-USB_VOLATILE USB_HANDLE rxHandle = 0;
+USB_VOLATILE USB_HANDLE rxHandle;
 
 void WriteFlashBlock(void);
 void WriteConfigBits(void);
@@ -173,7 +173,8 @@ void UserInit(void)
     ConfigsLockValue = 1;
     
     USBEnableEndpoint(HID_EP, USB_IN_ENABLED|USB_OUT_ENABLED|USB_HANDSHAKE_ENABLED|USB_DISALLOW_SETUP);
-    rxHandle = HIDRxPacket(HID_EP, (char *)&PacketFromPC, USB_PACKET_SIZE);
+    rxHandle = HIDRxPacket(HID_EP, (uint8_t *)&PacketFromPC, USB_PACKET_SIZE);
+    txHandle = 0;
 }
 
 /******************************************************************************
@@ -219,7 +220,7 @@ void ProcessIO(void)
         {
             //We received a new command from the host.  Copy the OUT packet from 
             //the host into a local buffer for processing.
-            rxHandle = HIDRxPacket(HID_EP, (char *)&PacketFromPC, USB_PACKET_SIZE); //Also re-arms the OUT endpoint to be able to receive the next packet
+            rxHandle = HIDRxPacket(HID_EP, (uint8_t *)&PacketFromPC, USB_PACKET_SIZE); //Also re-arms the OUT endpoint to be able to receive the next packet
             //HIDRxReport((char *)&PacketFromPC, USB_PACKET_SIZE);     //Also re-arms the OUT endpoint to be able to receive the next packet
             BootState = NOT_IDLE;   //Set flag letting state machine know it has a command that needs processing.
             
@@ -263,7 +264,7 @@ void ProcessIO(void)
                     //Init pad bytes to 0x00...  Already done after we received the QUERY_DEVICE command (just after calling HIDRxReport()).
 
                     //Now send the packet to the USB host software, assuming the USB endpoint is available/ready to accept new data.
-                    txHandle = HIDTxPacket(HID_EP, (char *)&PacketToPC, USB_PACKET_SIZE);
+                    txHandle = HIDTxPacket(HID_EP, (uint8_t *)&PacketToPC, USB_PACKET_SIZE);
                     BootState = IDLE;
                 }
                 break;
@@ -279,7 +280,6 @@ void ProcessIO(void)
                 //First erase main program flash memory
                 for(ErasePageTracker = START_PAGE_TO_ERASE; ErasePageTracker < (unsigned int)(MAX_PAGE_TO_ERASE + 1); ErasePageTracker++)
                 {
-                    ClearWatchdog();
                     #ifdef __XC8__
                         TBLPTRU = 0x00;
                         TBLPTRH = (uint8_t)((uint24_t)ErasePageTracker >> 2);
@@ -390,7 +390,7 @@ void ProcessIO(void)
                 //data over so it can get sent to the USB host software.
                 if(!HIDTxHandleBusy(txHandle))
                 {
-                    HIDTxPacket(HID_OUT_EP, (char *)&PacketToPC, USB_PACKET_SIZE);
+                    txHandle = HIDTxPacket(HID_EP, (uint8_t *)&PacketToPC, USB_PACKET_SIZE);
                     BootState = IDLE;
                 }
                 break;
@@ -428,7 +428,7 @@ void ProcessIO(void)
                 //Now actually command USB to send the packet to the host                   
                 if(!HIDTxHandleBusy(txHandle))
                 {
-                    HIDTxPacket(HID_OUT_EP, (char *)&PacketToPC, USB_PACKET_SIZE);
+                    txHandle = HIDTxPacket(HID_EP, (uint8_t *)&PacketToPC, USB_PACKET_SIZE);
                     BootState = IDLE;   //Packet will be sent, go back to idle state ready for next command from host
                 }       
                 break;
@@ -509,7 +509,6 @@ void SignFlash(void)
         if((i % WRITE_BLOCK_SIZE) == 0)
         {
             //The write latches are full, time to program the block.
-            ClearWatchdog();
             EECON1 = 0xA4;  //Write to flash on next WR = 1 operation
             UnlockAndActivate(CORRECT_UNLOCK_KEY);
         }    
@@ -574,8 +573,10 @@ void WriteFlashBlock(void)      //Use to write blocks of data to flash.
     static unsigned char CorrectionFactor;
 
     static const uint8_t* pROM;
+    
+    uint24_t romPtrAddress = ProgrammedPointer - BufferedDataIndex;
 
-    pROM = (const uint8_t*)((uint8_t)ProgrammedPointer - BufferedDataIndex);
+    pROM = (const uint8_t*)romPtrAddress;
     TBLPTRU = 0x00;
     TBLPTRH = (uint8_t)((uint16_t)pROM >> 8);
     TBLPTRL = (uint8_t)pROM;
@@ -776,18 +777,6 @@ void UnlockAndActivate(unsigned char UnlockKey)
     EECON1bits.WREN = 0;    //Good practice now to clear the WREN bit, as further protection against any accidental activation of self write/erase operations.
 }
 
-//Helper function to reduce code size when built with C18.  The ClrWdt() is an
-//inline assembly macro, and on the C18 compiler, if you execute an inline asm
-//instruction in a C function, it prevents the compiler from implementing
-//optimizations to that particular function (since the compiler doesn't know what
-//the user did in the inline asm).  Therefore, inline asm is more efficient if
-//implemented outside of large C functions, when using C18.
-void ClearWatchdog(void)
-{
-    ClrWdt();
-}
-
-
 //Note: The ClrWdt() and "_asm tblrdpostinc _endasm" are inline assembly language
 //instructions.  The ClearWatchdog() and  TableReadPostIncrement() functions are 
 //theoretically extraneous, since the operations being accomplished could be

bootloader/src/bootloader.h

@@ -29,9 +29,6 @@
 
 void UserInit(void);
 void ProcessIO(void);
-void ClearWatchdog(void);
-void DisableUSBandExecuteLongDelay(void);
-
 
 //Vector remapping/absolute address constants
 #define REMAPPED_APPLICATION_RESET_VECTOR       0x1C00

bootloader/src/main.c

@@ -9,22 +9,75 @@
 #include "usb.h"
 #include "bootloader.h"
 
-void main(void) {
+/* Private prototypes */
-    //UserInit();
+void main(void);
+void BootMain(void);
+
+const unsigned int FlashSignatureWord __at(APP_SIGNATURE_ADDRESS) = APP_SIGNATURE_VALUE;
+
+void main(void)
+{
+    //BootMain();
+    /**
+     * TODO: implement hardware IO-based method for forcing entry into bootloader
+     */
     
+    // normal operation: verify the firmware signature is valid. if it isn't enter
+    // bootloader (fw update) mode so valid firmware can be flashed
+//DoFlashSignatureCheck:
+    //Check if the application region flash signature is valid
+    if(*(const unsigned int*)APP_SIGNATURE_ADDRESS == APP_SIGNATURE_VALUE)
+    {
+        //The flash signature was valid, implying the previous
+        //erase/program/verify operation was a success.
+
+        //Also make sure the first WORD of program memory in the app space
+        //is not blank, meaning there is an application image programmed into the device.
+        if(*(const unsigned int*)REMAPPED_APPLICATION_RESET_VECTOR != 0xFFFF)
+        {
+            //Go ahead and jump out of bootloader mode into the application run mode
+            #asm
+                goto REMAPPED_APPLICATION_RESET_VECTOR
+            #endasm
+        }
+    }
+    //else the application image is missing or corrupt.  In this case, we
+    //need to stay in the bootloader mode, so the user has the ability to
+    //try (again) to re-program a valid application image into the device.
+    
+    BootMain();
+}
+
+void BootMain(void) __at(0x30)
+{
+    //Make sure interrupts are disabled for this code (could still be on,
+    //if the application firmware jumped into the bootloader via software methods)
+    INTCON = 0x00;
+
+    //Clear the stack pointer, in case the user application jumped into 
+    //bootloader mode with excessive junk on the call stack
+    STKPTR = 0x00;  
+
+    // End of the important parts of the C initializer.  This bootloader firmware does not use
+    // any C initialized user variables (idata memory sections).  Therefore, the above is all
+    // the initialization that is required.
+
     // initialize the USB framework
     USBDeviceInit();
     USBDeviceAttach();
     
+    // initialize the bootloader
+    UserInit();
+    
+    //Execute main loop
     while(1)
     {
+        //Need to call USBDeviceTasks() periodically.  This function takes care of
+        //processing non-USB application related USB packets (ex: "Chapter 9" 
+        //packets associated with USB enumeration)
         USBDeviceTasks();
         
-        // do nothing if: not connected to USB host, or the host put us in suspend state
+        ProcessIO();        //This is where all the actual bootloader related data transfer/self programming takes
-        if((USBGetDeviceState() < CONFIGURED_STATE) | USBIsDeviceSuspended())
+                            //place see ProcessIO() function in the BootPIC[xxxx].c file.
-            continue;
+    }//end while    
-
+}
-        // run application specific tasks
-        ProcessIO();
-    }
-}

common_src/memory.h

@@ -0,0 +1,37 @@
+/*************************************************************************
+ * Copyright (C) 2019 by Justin Byers
+ * 
+ * This file is part of clubdance_v2.
+ *
+ * clubdance_v2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * clubdance_v2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with clubdance_v2.  If not, see <https://www.gnu.org/licenses/>.
+ *************************************************************************/
+
+/**
+ * @file memory.
+ * @author Justin Byers
+ * @date August 11, 2019
+ * @brief 
+ *
+ */
+#ifndef MEMORY_
+#define	MEMORY_
+
+#define APP_FW_MEMORY_OFFSET 0x2000
+
+#define BOOTLOADER_ENTRYPOINT 0x001C
+
+#define APP_FW_VERSION_ADDRESS (APP_FW_MEMORY_OFFSET + 0x0016)
+
+#endif	/* MEMORY_ */
+

firmware/clubdance_v2.X/nbproject/configurations.xml

@@ -20,6 +20,7 @@
         </logicalFolder>
       </logicalFolder>
       <itemPath>../../common_src/system.c</itemPath>
+      <itemPath>../../common_src/memory.h</itemPath>
     </logicalFolder>
     <logicalFolder name="HeaderFiles"
                    displayName="Header Files"
@@ -99,7 +100,7 @@
         <property key="default-bitfield-type" value="true"/>
         <property key="default-char-type" value="true"/>
         <property key="define-macros" value="LINK_FOR_BOOTLOADER"/>
-        <property key="disable-optimizations" value="true"/>
+        <property key="disable-optimizations" value="false"/>
         <property key="extra-include-directories"
                   value="..\src;..\..\common_src\framework\usb\inc"/>
         <property key="favor-optimization-for" value="-speed,+space"/>
@@ -107,14 +108,14 @@
         <property key="garbage-collect-functions" value="true"/>
         <property key="identifier-length" value="255"/>
         <property key="local-generation" value="false"/>
-        <property key="operation-mode" value="free"/>
+        <property key="operation-mode" value="pro"/>
         <property key="opt-xc8-compiler-strict_ansi" value="false"/>
         <property key="optimization-assembler" value="true"/>
-        <property key="optimization-assembler-files" value="true"/>
+        <property key="optimization-assembler-files" value="false"/>
         <property key="optimization-debug" value="false"/>
         <property key="optimization-invariant-enable" value="false"/>
         <property key="optimization-invariant-value" value="16"/>
-        <property key="optimization-level" value="-O0"/>
+        <property key="optimization-level" value="-Os"/>
         <property key="optimization-speed" value="false"/>
         <property key="optimization-stable-enable" value="false"/>
         <property key="pack-struct" value="true"/>
@@ -129,7 +130,7 @@
       </HI-TECH-COMP>
       <HI-TECH-LINK>
         <property key="additional-options-checksum" value=""/>
-        <property key="additional-options-code-offset" value="1400"/>
+        <property key="additional-options-code-offset" value="1C00"/>
         <property key="additional-options-command-line" value=""/>
         <property key="additional-options-errata" value=""/>
         <property key="additional-options-extend-address" value="false"/>
@@ -140,7 +141,7 @@
         <property key="calibrate-oscillator-value" value="0x3400"/>
         <property key="clear-bss" value="true"/>
         <property key="code-model-external" value="wordwrite"/>
-        <property key="code-model-rom" value="default,-0-13FF,-1406-1407,-1416-1417"/>
+        <property key="code-model-rom" value="default,-0-1BFF,-1C06-1C07,-1C16-1C17"/>
         <property key="create-html-files" value="false"/>
         <property key="data-model-ram" value=""/>
         <property key="data-model-size-of-double" value="32"/>
@@ -251,6 +252,7 @@
         <archiverTool>
         </archiverTool>
         <loading>
+          <loadableFile>../../bootloader/clubdance_v2_bootloader.X/dist/default/production/clubdance_v2_bootloader.X.production.hex</loadableFile>
           <useAlternateLoadableFile>false</useAlternateLoadableFile>
           <parseOnProdLoad>false</parseOnProdLoad>
           <alternateLoadableFile></alternateLoadableFile>

firmware/src/main.c

@@ -22,16 +22,17 @@
  * @date 6 Aug 2019
  * @brief USB interface to 6-sensor DDR pads.
  */
+const unsigned int VersionWord __at(0x1C16) = 0x0100;
 #pragma warning disable 1510
 
 #include "usb.h"
 #include "padhal.h"
 #include "dancepad.h"
 
-#ifdef LINK_FOR_BOOTLOADER
+//#ifdef LINK_FOR_BOOTLOADER
 // only define this if building fw to be used with the bootloader
-const unsigned int VersionWord __at(0x1416) = 0x0100;
+
-#endif
+//#endif
 
 void main(void)
 {