I am using Keil µVision3 for simulating an ARM processor. To use CodeSourcery toolchain I set * GNU-Tool-Prefix: arm-none-linux-gnueabi- * Cygnus Folder: C:\Program Files\CodeSourcery\Sourcery G++\ But when I build the target, I receive the following message: Build target 'MCBSTM32' assembling STM32F10x.s... --- Error: failed to execute 'arm-none-linux-gnueabiarm-none-linux-gnueabiarm-none-linux-gnueabiarm-none-linux-gnueabi-ar' Target not created In fact, GNU-Tool_Prefix is concatenated 3 times before 'ar'. What is the reason for this problem?