st10 disassemble

Several years ago, my company produced a ST10F bootloader for use within our engineering department. As luck would have it, a serious bug has recently been detected in the bootloader, and the author and source code are long gone. I need to disassemble the bootloader binary in order to edit it. Do you know where I might obtain such a tool?

A disassembler for the C166/C167 family is available from Infineon:

http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/public_download.jsp?oid=10000&parent_oid=-8984

http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/public_download.jsp?oid=9999&parent_oid=-8984