Most of the time they use u-boot as a reference and then customize the u-boot to make their proprietary BL.
Thanks, Parth On Fri, Jan 28, 2011 at 1:43 PM, Tim Bird <[email protected]> wrote: > On 01/28/2011 01:20 PM, Earlence wrote: > > so what exactly is used and how do i get its code? > > Arun is wrong. See my answers below. > > > On Jan 28, 8:24�am, "Arun K. Singh" <[email protected]> wrote: > >> It has to be u-boot or a proprietary enhancement of same at best... > >> implementing a proprietary boot loader for Linux doesn't make much > >> sense ... > >> > >> Best Regards, > >> Arun K. Singhwww.crazydaks.com > >> > >> On Fri, Jan 28, 2011 at 12:38 PM, Earlence <[email protected]> > wrote: > >>> 1. What bootloader is used for the Linux kernel on android phones? > The bootloader for all Android phones that > I know of are proprietary, and are developed by the respective > phone manufacturer (or chip vendor) > . > >>> 2. where can I get its source code? > I don't think you can. > > >>> 3. Is it vendor specific and closed source? > Yes, see above. > > >>> 4. If so, how do these guys on XDA manage to replace it with another > >>> bootloader? > I'm not sure that they do. The bootloaders in the Android phones > I've worked with support booting from one of 2 flash partitions > ('boot' or 'recovery'). > > I believe (but I'm not sure) that the XDA guys utilize the recovery > partition to install a secondary bootloader (or linux image) to provide > features for this systems (like backups, upgrades, re-flashing, etc.) > > What is in the recovery partition normally is a special program > (not Linux or Android) that allows for reflashing. Many people > don't understand that this is a separate program from the first-stage > bootloader. > > You might want to ask the XDA guys for more information about what > they did. > > >>> 5. Keeping the above point in mind, is it possible to use an open > >>> source bootloader like LK or UBoot on an unlocked device? > I don't know. It depends on how the device is unlocked. > If the phone manufacturer put the initial bootloader in ROM, > then no. Also, some vendors utilize signing, making > changing the bootloader very difficult. > > -- Tim > > > ============================= > Tim Bird > Architecture Group Chair, CE Linux Forum > Senior Staff Engineer, Sony Network Entertainment > ============================= > > -- > unsubscribe: > [email protected]<android-kernel%[email protected]> > website: http://groups.google.com/group/android-kernel > -- unsubscribe: [email protected] website: http://groups.google.com/group/android-kernel
