cross-compiling SDL for uclinux

Dear all,

after cross-compiling sdl-1.2.5,then cross-compile the demos of test
directory,
but only the file testtypes can be compiled successfully.
when cross-compiling SDL-1.2.5, I use option --enable-static
--disable-shared.

there are some errors as follows:
testhread.tmp:In fucntion 'ThreadFunc':
testhread.tmp(.text+0x78):undefined reference to 'SDL_ThreadID'
testhread.tmp(.text+0x108):undefined reference to 'SDL_Delay'
testhread.tmp:In fucntion 'killed':
testhread.tmp(.text+0x1ac):undefined reference to 'SDL_Delay'
testhread.tmp:In fucntion 'main':
testhread.tmp(.text+0x220):undefined reference to 'SDL_Init'
testhread.tmp(.text+0x23c):undefined reference to 'SDL_GetError'
testhread.tmp(.text+0x2a0):undefined reference to 'SDL_Quit'
testhread.tmp(.text+0x2dc):undefined reference to 'SDL_CreateThread'
testhread.tmp(.text+0x304):undefined reference to 'SDL_GetError'
testhread.tmp(.text+0x368):undefined reference to 'SDL_Delay'
testhread.tmp(.text+0x3bc):undefined reference to 'SDL_WaitThread'
testhread.tmp(.text+0x3f4):undefined reference to 'SDL_CreateThread'
testhread.tmp(.text+0x41c):undefined reference to 'SDL_GetError'
testhread.tmp(.text+0x480):undefined reference to 'SDL_Delay'
testhread.tmp(.text+0x4bc):undefined reference to 'SDL_KillThread'
testhread.tmp(.text+0x51c):undefined reference to 'SDL_CreateThread'
testhread.tmp(.text+0x544):undefined reference to 'SDL_GetError'

how to solve it then?

Regards,
Andy