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manish12
Joined: 18 Jan 2009 Posts: 15
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what is bootloader ?? |
Posted: Sun Jan 18, 2009 8:22 am |
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i am new to this term bootloader ?
but well exp with mcs pic atmel avr.
i am new to pic18f series .
thank you ?
bootloader =/= firmware?
thank you. |
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asmallri
Joined: 12 Aug 2004 Posts: 1635 Location: Perth, Australia
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Posted: Sun Jan 18, 2009 8:38 am |
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Bootloader is firmware you put into a PIC. The firmware then allows an application program to be loaded into the PIC via serial port, Ethernet, SD/MMC card or some other interface depending on the bootloader.
Bootloaders enable you to upgrade software remotely, ship new software to customers to upgrade images in the field, or simple to enable you to develop and test new software without having to have a programmer attached to the PIC. _________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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manish12
Joined: 18 Jan 2009 Posts: 15
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how i can burn these two on same pic |
Posted: Sun Jan 18, 2009 9:00 pm |
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how i can burn these two on same pic ?
they are at diff location ? |
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asmallri
Joined: 12 Aug 2004 Posts: 1635 Location: Perth, Australia
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Re: how i can burn these two on same pic |
Posted: Sun Jan 18, 2009 9:52 pm |
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manish12 wrote: | how i can burn these two on same pic ?
they are at diff location ? |
Yes they might be in completely different areas of memory or they could be contiguous. Generally, but not always, bootloaders are designed to be transparent to the application program. You program the bootloader into the PIC and, from then on, use the bootloader to program the PIC. When manufacturing a product, you want to avoid the second step and build an image that includes both the bootloader and the PIC. If the bootloader and PIC were developed with the same development platform, this may be straight forward. Otherwise you need to use a script that can combine the two hex files to product a single image.
For low volume products that have a high shelf life between sales, you might produce it only with the bootloader and then add the production image at final platform testing before shipment. This is the step when platform specific configuration would normally have to be done anyway such as assigning a MAC address, serial number, customer specific identifier etc.
It is not uncommon to do both. That is, build a common image knowing full well the application part will be changed as soon as the system is deployed. _________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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FvM
Joined: 27 Aug 2008 Posts: 2337 Location: Germany
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Posted: Mon Jan 19, 2009 12:20 am |
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Quote: | It is not uncommon to do both. That is, build a common image knowing full well the application part will be changed as soon as the system is deployed. |
Yes, that's the ususal way. As an additional requirement, a bootloader should allow safe recovery from all kinds of update failures. The bootloader should never be overwritten during update and involve hardware write protection for the bootloader flash area (if possible with a device family). |
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