I recommend you ask your question on Texas Instruments E2E website e2e.ti.com <http://e2e.ti.com/>
I’m not sure anyone here would have this level of detailed knowledge. Regards, John > On Aug 16, 2016, at 2:22 PM, val <[email protected]> wrote: > > Hi, all. My question is that: > > I need to make use a Rom code's raw mode of reading its payloads from both SD > cards and eMMC. > My question is whether the CH (Configuration Header) needed in this case? > TI's TRM on Sitara am335x states CH must be located at the sector #0, > and says it might be void (only containing a _disabled_ CHSETTINGS item), > but it is very unclear with respect of its size and offsets. and also it's > not clear whether it's needed at all. > Quote: > "The raw mode is detected by reading sectors #0, #256, #512, #768. > The content of these sectors is then verified for presence of a TOC structure > as described in Section 26.1.9." > > But section 26.1.9 even doesn't mention CH, just a GP header. > And the TRM on Sitara 572x states CH is optional for GP devices. > > I mean, if I place my binary into LBA #0 (first sector) with the only GP > header attached and no CH, > would the Rom code load it? > > I can't use MBR/FAT mode, because there is GPT and PMBR there. > > I wanted to learn this, and before bothering you, I checked eMMC content on > BBB, > since TI's TRM states for embedded memories ROM code doesn't use MBR/FAT mode. > So on eMMC there should be a valid example of CH with TOC in the first > sector. But on BBB, somehow, > and it is clearly seen, the FAT/MBR is used and there is no any TOC at all > (first bytes > of the first sector are filled with zeros up to the Partition records). TRM > states if the first > 4 bytes are 0x00 or 0xFF this device is considererd as not containig the > image to load: > Quote > "The detection of whether an image is present or not on a selected device > depends on the first few bytes. > On a GP Device type a booting image is considered to be present when the > first four bytes of the sector is > not equal to 0000 0000h or FFFF FFFFh." > > Maybe there are some knowledgeable people here, > tell me please, is CH needed (for the Romcode) in the raw mode for GP memory > booting and > what its minimal content is? Because I cannot let it occupy the entire 512 > byte, only part > of the code block (first 440 bytes) of the Protective MBR may be used. > > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/0908e47d-6d81-46a0-baf9-260e7e9794a6%40googlegroups.com > > <https://groups.google.com/d/msgid/beagleboard/0908e47d-6d81-46a0-baf9-260e7e9794a6%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/93D9AE87-1D27-4629-B70A-A162BD5B4458%40gmail.com. For more options, visit https://groups.google.com/d/optout.
