There is no 3.71 SDK.
Simple explanation:
Module Info:

Quote:PSP_MODULE_INFO("App Name", PSP_MODULE_USER, 1, 1);

PSP_MAIN_THREAD_ATTR:

Quote:PSP_MAIN_THREAD_ATTR(PSP_THREAD_ATTR_USER);

PSP's Heap size allowed for your application:

Quote:PSP_HEAP_SIZE_KB(20480);

Add there to your makefile:

Quote:BUILD_PRX=1
PSP_FW_VERSION=371

You cannot make any kernel calls! If you want to use kernel functions, you must create a separated prx in kernel mode and run the function from there.