Cross Compiler Binary Execute Error

Question

I just built a cross compiler using crosstools "mips-unknown-linux-gnu-gcc" and I compiled a hello world program. The compilation went fine using the command: "mips-unknown-linux-gnu-g++ hello.cpp -o hello" but when I run the command "./hello" I get the following error:

babbage-dasnyder 50% mips-unknown-linux-gnu-g++ hello.cpp -o hello
babbage-dasnyder 51% ./hello
./hello: Exec format error. Wrong Architecture.

Why is this? Did I make the wrong cross-compiler? I'm running this on a linux machine.

Just as a note, crosstools did say it could run a trivial program:

+ /home/seas/grad/dasnyder/opt/crosstool/gcc-3.4.5-glibc-2.3.6/mips-unknown-linux-gnu/bin/mips-unknown-linux-gnu-gcc -static hello.c -o mips-unknown-linux-gnu-hello-static
+ /home/seas/grad/dasnyder/opt/crosstool/gcc-3.4.5-glibc-2.3.6/mips-unknown-linux-gnu/bin/mips-unknown-linux-gnu-gcc hello.c -o mips-unknown-linux-gnu-hello
+ test -x /home/seas/grad/dasnyder/opt/crosstool/gcc-3.4.5-glibc-2.3.6/mips-unknown-linux-gnu/bin/mips-unknown-linux-gnu-g++
+ cat
+ /home/seas/grad/dasnyder/opt/crosstool/gcc-3.4.5-glibc-2.3.6/mips-unknown-linux-gnu/bin/mips-unknown-linux-gnu-g++ -static hello2.cc -o mips-unknown-linux-gnu-hello2-static
+ /home/seas/grad/dasnyder/opt/crosstool/gcc-3.4.5-glibc-2.3.6/mips-unknown-linux-gnu/bin/mips-unknown-linux-gnu-g++ hello2.cc -o mips-unknown-linux-gnu-hello2
+ echo testhello: C compiler can in fact build a trivial program.
testhello: C compiler can in fact build a trivial program.
+ test '' = 1
+ test '' = 1
+ test '' = 1
+ test 1 = ''
+ echo Done.
Done.

Answer 1

Just as a note, crosstools did say it could run a trivial program:

testhello: C compiler can in fact build a trivial program.

When you cross-compile to a different architecture, you are generating instructions for the new architecture and thus you may not be able to run these instructions on your current architecture. You are cross-compiling to be able to compile the code on a more powerful machine and then transfer it to the device for testing. If you are wanting to test the code directly on your machine you need to compile with your native architecture's compiler.