Hi sandeep, On Sun, Jul 24, 2011 at 9:18 PM, sandeep kumar <coolsandyforyou@xxxxxxxxx> wrote: > Hi all, > In Android target mobiles there is a facility called "Ramdump", where the > entire Ram image is copied to a file > as the kernel goes to panic. > > Ramdump is implemented like this > 1) As the panic() function is called target will be reset. > 2) Bootloader boots up in specific mode, where it enables the USB driver in > uploading mode. > 3) Through USB entire RAM content is copied to a file in the host computer. > 4) This file is parsed through different tools and we can get the logs info > wat exactly happened just before kernel panic happend. > > > Now here is the interesting part, > While the mobile's RAM image is being uploaded to host computer, our > bootloader is still running in the mobile's RAM. > How can it copy its own running region. > > This triggered me the following questions, > > 1) When bootloader runs, will it run in a specific reserved region of RAM or > it takes entire RAM? Some do - it depends on the processor. Some processors have a bunch of internal static RAM that the bootloader runs out of. > 2) When it hands over the control to kernel, will it relinquish the entire > RAM or certain part of RAM is reserved for it? Not sure. > 3) Does kernel use the entire RAM while running? It depends on how things are configured. > 4) When the kernel is running, is ther any chance that, control again be > taken back to bootloader?(coz i saw in bootloader code kernel is being > called, > > after that code also some code is there,some printks and error handling > stuff) I don't think that the kernel ever gives control back to the bootloader. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
