John Devereux wrote:> Les Cargill <lcargill99@comcast.com> writes: > >> prashanthgr.1992 wrote: >>> Hi all, >>> I am new to Embedded design industry. >> >> Get out while you can. >> >>> I have some questions regarding C and bootloader. >>> 1. What is the use of pointers, function pointers, structures, structure >>> pointer, array of structures, array of pointers, unions with respect to >>> embedded programming? >> >> Yes! >> >>> 2. Why we need bootloader? What is the use of bootloader although we ve >>> debuggers for programming? >> >> You don't need it since you use debugger. >> >>> 3. Why PBL and SBL?? Why not a single memory? >>> >> >> Some memory is more equal than other. > > Vladimir, come back, we need you... >Very much so :) -- Les Cargill
Bootloader
Started by ●February 4, 2014
Reply by ●February 8, 20142014-02-08
Reply by ●February 8, 20142014-02-08
prashanthgr.1992, you need help on the ground. The non-snark version: prashanthgr.1992 wrote:> Hi all, > I am new to Embedded design industry. > I have some questions regarding C and bootloader. > 1. What is the use of pointers, function pointers, structures, structure > pointer, array of structures, array of pointers, unions with respect to > embedded programming?Those are just elements of 'C' programming and not constrained to embedded.> 2. Why we need bootloader? What is the use of bootloader although we ve > debuggers for programming?Supposedly, you really cannot ship a product with a debugger attached. A boot loader "loads" a program at "boot" time. Examples might be LILO or U-Boot. your question as asked leads to a lot of questions. http://stackoverflow.com/questions/15696258/what-is-bootloader-and-startup-code-in-the-embedded-systems> 3. Why PBL and SBL?? Why not a single memory? >Beats me. Sounds specific to an architecture.> > > --------------------------------------- > Posted through http://www.EmbeddedRelated.com >-- Les Cargill
Reply by ●February 8, 20142014-02-08
David Brown wrote:> On 04/02/14 19:51, Tim Wescott wrote: >> On Tue, 04 Feb 2014 12:19:29 -0600, prashanthgr.1992 wrote: >> >>> 2. Why we need bootloader? What is the use of bootloader although we ve >>> debuggers for programming? >> >> You don't _need_ a bootloader, per se. Often if you've got some really >> big software load (like linux with applications, or VxWorks, etc.) a >> bootloader makes your life easy. >> >> A shippable product does not have a debugger attached to it, any more >> than your average 18 year old kid still has an umbilical cord. >> > > I made a shipping product with a debugger still attached. I used an > FTDI 2232C chip with one channel connected to the microcontroller's UART > (for normal PC to board communication while running), and the other as a > JTAG-style connection (BDM, to be accurate) to the microcontroller. > While it didn't support full debugging, it supported "programming over > the debugger" from the PC for downloading and updating the software. It > worked very well, and is a method I could well use again - especially > for ARM chips with OpenOCD running on the PC side. > >Do you mean "shipped" as in "run at a test site" or "as production"? Having an end customer run a debugger at boot time*, or even at update time seems troublesome. *not that you said you did that; it's a bit ambiguous. Even on stuff with 68000 or Codlfire-in-68000, long as there's FLASH memory for program storage, I've mainly seen people write program loaders over a 232 port for going on 25 years now. Even better; have a filesystem in FLASH. -- Les Cargill
