How to change to the nios2-elf-gcc compiler ?

http://www.alterawiki.com/wiki/dasuboot

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The default compiler is nios2-elf-gcc, which comes with nios2eds.

If you want to use nios2-linux-gnu-gcc to build u-boot, you may set,

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I dont change the compiler to the "nios2-linux-gnu-" "nios2-linux-uclibc-"only use the

"nios2-elf-gcc" compiler, then run like this

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make my_nios2_config

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# make my_nios2_config
make: nios2-elf-gcc: Command not found
/bin/sh: nios2-elf-gcc: command not found
dirname: missing operand
Try `dirname --help' for more information.
/bin/sh: nios2-elf-gcc: command not found
dirname: missing operand
Try `dirname --help' for more information.
Configuring for my_nios2 board...
# 

Is nios2-linux-uclibc-gcc instead of the nios2-elf-gcc compiler to be the default compiler in the nios2-linux-20100621 tarball ?

# nios2-linux-uclibc-gcc -v
Reading specs from /home/nios2-linux/toolchain-build/build/nios2/lib/gcc/nios2-linux-uclibc/3.4.6/specs
Configured with: /home/nios2-linux/toolchain-build/../gcc3/configure --prefix=/home/nios2-linux/toolchain-build/build/nios2 --target=nios2-linux-uclibc --enable-languages=c,c++ --disable-__cxa_atexit --enable-target-optspace --with-gnu-ld --disable-shared --disable-nls --enable-threads --enable-multilib --enable-cxx-flags=-static
Thread model: posix
gcc version 3.4.6

Does it mean using the "nios2-linux-uclibc" is right, "nios2-elf-gcc" is wrong ?

PS: I use the "nios2-linux-uclibc"compiler compiling the u-boot successfully,but there's no u-boot.elf file!

Using the "nios2-elf-gcc" compiler maybe generates the u-boot.elf?