Added untested support for erasing a specific portion of the SIMM

(in 256 KB increments). Won't be able to test it until I implement it in
the control software as well, but I think it should work.

external_mem.c

@@ -256,6 +256,91 @@ void ExternalMem_EraseChips(uint8_t chipsMask)
 	ExternalMem_WaitCompletion(chipsMask);
 }
 
+bool ExternalMem_EraseSectors(uint32_t address, uint32_t length, uint8_t chipsMask)
+{
+	bool result = false;
+
+	// Make sure the area requested to be erased is on 64 KB boundaries.
+	// True, the 2 MB SIMM doesn't require 64 KB boundaries, but I'm going to
+	// keep it to 2 MB boundaries to simplify everything.
+#define ERASABLE_SECTOR_SIZE	(64*1024UL*1024UL)
+	if ((address & ERASABLE_SECTOR_SIZE) ||
+		(length & ERASABLE_SECTOR_SIZE))
+	{
+		return false;
+	}
+
+	// We're good to go. Let's do it.
+
+	if (curChipType == ChipType8BitData_4MBitSize)
+	{
+#define SECTOR_SIZE_4MBIT	(128)
+		// This chip sucks because you have to erase each sector with its own
+		// complete erase unlock command, which can take a while. At least
+		// individual erase operations are much faster on this chip...
+		while (length)
+		{
+			// Start the erase command
+			ExternalMem_UnlockChips(chipsMask);
+			ExternalMem_WriteCycle(0x55555555UL, 0x80808080UL);
+			ExternalMem_UnlockChips(chipsMask);
+
+			// Now provide a sector address, but only one. Then the whole
+			// unlock sequence has to be done again after this sector is done.
+			ExternalMem_WriteCycle(address, 0x20202020UL);
+
+			address += SECTOR_SIZE_4MBIT;
+			length -= SECTOR_SIZE_4MBIT;
+
+			// Wait for completion of this individual erase operation before
+			// we can start a new erase operation.
+			ExternalMem_WaitCompletion(chipsMask);
+		}
+
+		result = true;
+	}
+	else if (curChipType == ChipType8Bit16BitData_16MBitSize)
+	{
+#define SECTOR_SIZE_16MBIT	(64*1024UL*1024UL)
+		// This chip is nicer because it can take all the sector addresses at
+		// once and then do the final erase operation in one fell swoop.
+
+		// Start the erase command
+		ExternalMem_UnlockChips(chipsMask);
+		ExternalMem_WriteCycle(0xAAAAAAAAUL, 0x80808080UL);
+		ExternalMem_UnlockChips(chipsMask);
+
+		// Now provide as many sector addresses as needed to erase.
+
+		// The first address is a bit of a special case because the boot sector
+		// actually has finer granularity for sector sizes.
+		if (address == 0)
+		{
+			ExternalMem_WriteCycle(0x00000000UL, 0x30303030UL);
+			ExternalMem_WriteCycle(0x00004000UL, 0x30303030UL);
+			ExternalMem_WriteCycle(0x00006000UL, 0x30303030UL);
+			ExternalMem_WriteCycle(0x00008000UL, 0x30303030UL);
+			address += SECTOR_SIZE_16MBIT;
+			length -= SECTOR_SIZE_16MBIT;
+		}
+
+		// The remaining sectors can use a more generic algorithm
+		while (length)
+		{
+			ExternalMem_WriteCycle(address, 0x30303030UL);
+			address += SECTOR_SIZE_16MBIT;
+			length -= SECTOR_SIZE_16MBIT;
+		}
+
+		// Wait for completion of the entire erase operation
+		ExternalMem_WaitCompletion(chipsMask);
+
+		result = true;
+	}
+
+	return result;
+}
+
 void ExternalMem_WaitCompletion(uint8_t chipsMask)
 {
 	// Mark the chips not requested as already completed,
@@ -408,3 +493,8 @@ void ExternalMem_SetChipType(ChipType type)
 {
 	curChipType = type;
 }
+
+ChipType ExternalMem_GetChipType(void)
+{
+	return curChipType;
+}

external_mem.h

@@ -94,6 +94,7 @@ void ExternalMem_IdentifyChips(struct ChipID *chips);
 
 // Erases the chips requested
 void ExternalMem_EraseChips(uint8_t chipsMask);
+bool ExternalMem_EraseSectors(uint32_t address, uint32_t length, uint8_t chipsMask);
 
 // Writes a byte to the chips requested at the specified address
 void ExternalMem_WriteByteToChips(uint32_t address, uint32_t data, uint8_t chipsMask);
@@ -107,5 +108,6 @@ uint8_t ExternalMem_Write(uint32_t startAddress, uint32_t *buf, uint32_t len, ui
 
 // Tells which flash command protocol to use
 void ExternalMem_SetChipType(ChipType type);
+ChipType ExternalMem_GetChipType(void);
 
 #endif /* EXTERNAL_MEM_H_ */

programmer_protocol.h

@@ -45,7 +45,8 @@ typedef enum ProgrammerCommand
     SetSIMMTypePLCC32_2MB,
     SetSIMMTypeLarger,
     SetVerifyWhileWriting,
-    SetNoVerifyWhileWriting
+    SetNoVerifyWhileWriting,
+    ErasePortion
 } ProgrammerCommand;
 
 // After a command is sent, the programmer will always respond with
@@ -166,4 +167,21 @@ typedef enum ComputerBootloaderEraseWriteRequest
 	ComputerBootloaderCancel
 } ComputerBootloaderEraseWriteRequest;
 
+// -------------------------  ERASE PORTION OF CHIP PROTOCOL  -------------------------
+// If the command is ErasePortion, the programmer will reply CommandReplyOK.
+// Next, the program will send the beginning position to erase as a 4-byte little
+// endian integer, followed by the length to erase as a 4-byte little endian
+// integer. The programmer will reply with ProgrammerErasePortionOK to signify
+// that the erase is beginning, followed by ProgrammerErasePortionFinished when
+// everything is done.
+// The length and position to erase must be on 256 KB boundaries and shouldn't
+// go past the end of the selected type of chip. If any error occurs, it will
+// reply with ProgrammerErasePortionError instead.
+typedef enum ProgrammerErasePortionOfChipReply
+{
+	ProgrammerErasePortionOK = 0,
+	ProgrammerErasePortionError,
+	ProgrammerErasePortionFinished
+};
+
 #endif /* PROGRAMMER_PROTOCOL_H_ */

usb_serial/usb_serial.c

@@ -34,6 +34,7 @@
 #define MAX_CHIP_SIZE				(2UL * 1024UL * 1024UL)
 #define READ_CHUNK_SIZE_BYTES		1024UL
 #define WRITE_CHUNK_SIZE_BYTES		1024UL
+#define ERASE_SECTOR_SIZE_BYTES		(256UL * 1024UL)
 #if ((READ_CHUNK_SIZE_BYTES % 4) != 0)
 #error Read chunk size should be a multiple of 4 bytes
 #endif
@@ -54,7 +55,8 @@ typedef enum ProgrammerCommandState
 	ReadingChipsReadLength,
 	ReadingChips,
 	ReadingChipsUnableSendError,
-	WritingChips
+	WritingChips,
+	ErasePortionReadingPosLength
 } ProgrammerCommandState;
 static ProgrammerCommandState curCommandState = WaitingForCommand;
 
@@ -66,6 +68,8 @@ static uint8_t readLengthByteIndex;
 static int16_t writePosInChunk = -1;
 static uint16_t curWriteIndex = 0;
 static bool verifyDuringWrite = false;
+static uint32_t erasePosition;
+static uint32_t eraseLength;
 
 // Private functions
 void USBSerial_HandleWaitingForCommandByte(uint8_t byte);
@@ -74,6 +78,7 @@ void USBSerial_HandleReadingChipsReadLengthByte(uint8_t byte);
 void USBSerial_SendReadDataChunk(void);
 void USBSerial_HandleWritingChipsByte(uint8_t byte);
 void USBSerial_ElectricalTest_Fail_Handler(uint8_t index1, uint8_t index2);
+void USBSerial_HandleErasePortionReadPosLengthByte(uint8_t byte);
 
 // Read/write to USB serial macros -- easier than retyping
 // CDC_Device_XXX(&VirtualSerial_CDC_Interface...) every time
@@ -107,6 +112,9 @@ void USBSerial_Check(void)
 			case WritingChips:
 				USBSerial_HandleWritingChipsByte((uint8_t)recvByte);
 				break;
+			case ErasePortionReadingPosLength:
+				USBSerial_HandleErasePortionReadPosLengthByte((uint8_t)recvByte);
+				break;
 			}
 		}
 	}
@@ -227,6 +235,13 @@ void USBSerial_HandleWaitingForCommandByte(uint8_t byte)
 		verifyDuringWrite = false;
 		SendByte(CommandReplyOK);
 		break;
+	case ErasePortion:
+		readLengthByteIndex = 0;
+		eraseLength = 0;
+		erasePosition = 0;
+		curCommandState = ErasePortionReadingPosLength;
+		SendByte(CommandReplyOK);
+		break;
 	// We don't know what this command is, so reply that it was invalid.
 	default:
 		SendByte(CommandReplyInvalid);
@@ -416,6 +431,76 @@ void USBSerial_ElectricalTest_Fail_Handler(uint8_t index1, uint8_t index2)
 	SendByte(index2);
 }
 
+// If we're figuring out the position/length to erase, parse it here.
+void USBSerial_HandleErasePortionReadPosLengthByte(uint8_t byte)
+{
+	// Read in the position and length to erase
+	if (readLengthByteIndex < 4)
+	{
+		erasePosition |= (((uint32_t)byte) << (8*readLengthByteIndex));
+	}
+	else
+	{
+		eraseLength |= (((uint32_t)byte) << (8*(readLengthByteIndex - 4)));
+	}
+
+	if (++readLengthByteIndex >= 8)
+	{
+		ChipType chipType = ExternalMem_GetChipType();
+		bool eraseSuccess = false;
+
+		// Ensure they are both within limits of sector size erasure
+		if (((erasePosition & ERASE_SECTOR_SIZE_BYTES) == 0) &&
+			((eraseLength & ERASE_SECTOR_SIZE_BYTES) == 0))
+		{
+			uint32_t boundary = eraseLength + erasePosition;
+
+			// Ensure they are within the limits of the chip size too
+			if (chipType == ChipType8BitData_4MBitSize)
+			{
+				if (boundary <= (2 * 1024UL * 1024UL))
+				{
+					// OK! We're erasing certain sectors of a 2 MB SIMM.
+					SendByte(ProgrammerErasePortionOK);
+					CDC_Device_Flush(&VirtualSerial_CDC_Interface);
+					if (ExternalMem_EraseSectors(erasePosition/NUM_CHIPS,
+							eraseLength/NUM_CHIPS, ALL_CHIPS))
+					{
+						eraseSuccess = true;
+					}
+				}
+			}
+			else if (chipType == ChipType8Bit16BitData_16MBitSize)
+			{
+				if (boundary <= (8 * 1024UL * 1024UL))
+				{
+					// OK! We're erasing certain sectors of an 8 MB SIMM.
+					SendByte(ProgrammerErasePortionOK);
+					CDC_Device_Flush(&VirtualSerial_CDC_Interface);
+					if (ExternalMem_EraseSectors(erasePosition/NUM_CHIPS,
+							eraseLength/NUM_CHIPS, ALL_CHIPS))
+					{
+						eraseSuccess = true;
+					}
+				}
+			}
+		}
+
+		if (eraseSuccess)
+		{
+			// Not on a sector boundary for erase position and/or length
+			SendByte(ProgrammerErasePortionFinished);
+			curCommandState = WaitingForCommand;
+		}
+		else
+		{
+			// Not on a sector boundary for erase position and/or length
+			SendByte(ProgrammerErasePortionError);
+			curCommandState = WaitingForCommand;
+		}
+	}
+}
+
 // LUFA event handler for when the USB configuration changes.
 void EVENT_USB_Device_ConfigurationChanged(void)
 {