Optimize unique serial number reading code for size -- remove atoi/toupper references...

diff --git a/LUFA/Drivers/USB/LowLevel/DevChapter9.c b/LUFA/Drivers/USB/LowLevel/DevChapter9.c
index 4014ed1..feaabce 100644 (file)
--- a/LUFA/Drivers/USB/LowLevel/DevChapter9.c
+++ b/LUFA/Drivers/USB/LowLevel/DevChapter9.c
@@ -182,27 +182,49 @@ static void USB_Device_GetDescriptor(void)
        #if !defined(NO_INTERNAL_SERIAL) && (defined(USB_SERIES_6_AVR) || defined(USB_SERIES_7_AVR))\r
        if (USB_ControlRequest.wValue == ((DTYPE_String << 8) | USE_INTERNAL_SERIAL))\r
        {\r
-               uint8_t SignatureDescriptor[2 + (sizeof(int16_t) * 12)];\r
-\r
-               SignatureDescriptor[0] = sizeof(SignatureDescriptor);\r
-               SignatureDescriptor[1] = DTYPE_String;\r
+               struct\r
+               {\r
+                       USB_Descriptor_Header_t Header;\r
+                       int16_t                 UnicodeString[12];\r
+               } SignatureDescriptor;\r
+\r
+               #if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES)\r
+                       SignatureDescriptor.Header.Size            = sizeof(SignatureDescriptor);\r
+                       SignatureDescriptor.Header.Type            = DTYPE_String;\r
+               #else\r
+                       SignatureDescriptor.Header.bLength         = sizeof(SignatureDescriptor);\r
+                       SignatureDescriptor.Header.bDescriptorType = DTYPE_String;\r
+               #endif\r
                \r
-               uint16_t* SigUnicodeChars = (uint16_t*)&SignatureDescriptor[2];\r
+               uint8_t  SigReadAddress  = 0x0E;                \r
+               bool     OddRead         = false;\r
 \r
-               for (uint8_t SerialByteNum = 0; SerialByteNum < 6; SerialByteNum++)\r
+               for (uint8_t SerialCharNum = 0; SerialCharNum < 12; SerialCharNum++)\r
                {\r
-                       char ConvSigString[3];\r
-\r
-                       itoa(boot_signature_byte_get(0x0E + SerialByteNum), ConvSigString, 16);\r
+                       uint8_t SerialByte = boot_signature_byte_get(SigReadAddress);\r
                        \r
-                       SigUnicodeChars[0] = toupper(ConvSigString[0]);\r
-                       SigUnicodeChars[1] = toupper(ConvSigString[1]);\r
+                       if (OddRead)\r
+                       {\r
+                               SerialByte >>= 4;\r
+                               SigReadAddress++;\r
+                       }\r
+                       else\r
+                       {\r
+                               SerialByte &= 0x0F;\r
+                       }\r
                        \r
-                       SigUnicodeChars += 2;\r
+                       OddRead = !(OddRead);\r
+\r
+                       if (SerialByte < 0x0A)\r
+                         SerialByte += '0';\r
+                       else\r
+                         SerialByte += ('A' - 0x0A);\r
+\r
+                       SignatureDescriptor.UnicodeString[SerialCharNum] = SerialByte;\r
                }\r
                \r
                Endpoint_ClearSETUP();\r
-               Endpoint_Write_Control_Stream_LE(SignatureDescriptor, sizeof(SignatureDescriptor));\r
+               Endpoint_Write_Control_Stream_LE(&SignatureDescriptor, sizeof(SignatureDescriptor));\r
                Endpoint_ClearOUT();\r
 \r
                return;\r