Hi, Thank you all for your responses. I got the answer I was looking for: > Hello Rajat, > > Indeed, the i386 is for 32bits kernels, and x86_64 for 64 bits ones. If you > generate the configurations using "make ARCH=x86 defconfig" and "make > ARCH=i386 defconfig", you can easily compare the resulting configurations : > > .config from i386_defconfig : > # > # Automatically generated file; DO NOT EDIT. > # Linux/i386 3.17.0-rc1 Kernel Configuration # # CONFIG_64BIT is not set > CONFIG_X86_32=y CONFIG_X86=y CONFIG_INSTRUCTION_DECODER=y > CONFIG_OUTPUT_FORMAT="elf32-i386" > CONFIG_ARCH_DEFCONFIG="arch/x86/configs/i386_defconfig" > ... > > .config from x86_64_defconfig : > # > # Automatically generated file; DO NOT EDIT. > # Linux/x86 3.17.0-rc1 Kernel Configuration # CONFIG_64BIT=y > CONFIG_X86_64=y CONFIG_X86=y CONFIG_INSTRUCTION_DECODER=y > CONFIG_OUTPUT_FORMAT="elf64-x86-64" > CONFIG_ARCH_DEFCONFIG="arch/x86/configs/x86_64_defconfig" > ... > > As you can see, i386 is the 32 bits variant of the x86 architecture. There are of > course many more differences between these two configurations. > > Regards, > > Hubert Thanks all again, Rajat > -----Original Message----- > From: Valdis.Kletnieks@xxxxxx [mailto:Valdis.Kletnieks@xxxxxx] > Sent: Tuesday, September 09, 2014 7:28 AM > To: Matthias Brugger > Cc: Rajat Jain; linux-newbie@xxxxxxxxxxxxxxx; kernelnewbies > Subject: Re: x86_64_defconfig and i386_defconfig: What is the difference? > > On Tue, 09 Sep 2014 16:06:07 +0200, Matthias Brugger said: > > > > Can someone tell me if the i386 one is to be used when we want to > > > build for a 32bit machine and the x86_64 is to be used for 64 bit machine? > > > > You can build the kernel with any architecture for any architecture. > > This is called cross-compiling. The homepage [0] should explain you > > how to do that. > > Right, but you still need to use a .config appropriate for the target machine, > which is what I think Rajat was asking about. > > A defconfig is usually only known verified to boot on a few (possibly one) > examples of that architecture hardware. For embedded ARM, it may be one > specific development board or hardware device. For x86, I think they try to > keep it "will probably kind of sort of boot on generic PC hardware with a > common distro, but anything fancylike a webcam or better graphics than "vga > tty emulation" may not work". > > A defconfig is pretty much just a proof of concept starting point for an actual > working config for a given hardware system. -- To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs
