Booting Linux Kernel without bootloader

Parav Pandit paravpandit at
Wed Aug 2 13:49:07 EST 2006

--- Milton Miller <miltonm at> wrote:

> On Tue Jul 25 2006 05:30:39 PM CDT,  Clint Thomas 
> wrote:
> > Basically, the system I want linux running on does
> not require the
> > initialization of hardware that U-boot provides,
> or at least it does not
> > need it to boot the linux kernel. I want to load
> an uncompressed linux
> > kernel into memory and start the execution of the
> kernel, without using
> > any kind of bootloader. Is this possible? Or does
> linux need some kind
> > of firmware or other software to tell it to start
> executing? Thanks for
> > any info you might have.
> To run a powerpc (not ppc, which will be removed)
> kernel, in addition to the uncompressed kernel you
> will need to supply a device tree structure, point
> r3 to it, zero r5, and set r4 to the load address
> (zero as you have described).  See
> Documentation/powerpc/booting-without-of.txt for
> details.  Then arrange for you processor to start
> executing at address 0.  Note that /vmlinux has an
> elf header, you can use objcopy to remove it or
> adjust r4 and your start point; the kernel will copy
> itself to 0, clear bss and set up the stack. The
> device tree structure must be placed above the bss
> space in memory, not just the initialized data.  

Linux kernel does the bss cleaning after
start_kernel() even though boot loader does it. So one
step less.


> milton
> _______________________________________________
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> Linuxppc-embedded at

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