2009/2/1 Denys Vlasenko <[email protected]>: > On Saturday 31 January 2009 07:18, loody wrote: >> > Dear all: >> > I am porting kernel on my arm platform and I wrote a userspace >> > program, hello world. >> > But I cannot see the "hello world". >> > >> > my environment is: >> > 1. uclinux.dist 2008 >> > 2. and I put my source code under user and compile it. >> > 3. I use arm-linux-2006 to compile kernel >> > 4. I use arm-linux-2007 to compile my hello world. >> hi: >> I have one question about my problem. >> Can I replace the kernel execute command, "/init", as "/hello"; that >> means the first user space program is hello, not standard int. >> Is that the problem which make printt not workable? >> >> I have no idea whether kernel has to do something in "init" such that >> "hello" can call printf to show message. > > [f]printf ultimately results in write() syscalls performed on > open file descriptors. > > If you have trouble verifying that your userspace programs > are able to execute, start with this test program: > > int main() { > write(1, "Hello\n", 6); > for (;;) > continue; > } > > Compile it and run as init. You should see "Hello" > message. If you don't, your toolchain is producing broken > executables. > -- > vda >
Hi: I have search the calls.S in arch/arm/kernel, but I cannot find the sys call, write, you mention. ( I use arm platform, so I search the syscalls implemented by arm) Is it a wrap function? If so, I guess I should include some header to do so. But I have no idea what header I can use. appreciate your help, miloody -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
