Hi Darwin, On Mon, 26 May 2014 09:11:35 -0700, Darwin Rambo <dra...@broadcom.com> wrote:
> Hi Albert, > > The previous stage bootloader (which I had no control over) wanted it's > header to be aligned to a 512 byte MMC block boundary, presumably since > this allowed DMA operations without copy/shifting. At the same time, I > didn't want to hack a header into start.S because I didn't want to carry > another downstream patch. So I investigated if I could shift u-boot's > base address as a feature that would allow an aligned header to be used > without the start.S patch. > > I know that a custom header patch to start.S would work, and that a > header plus padding will also work. But I found out that you can align > the base on certain smaller offsets if you keep the relocation offset at > nice boundaries like 0x1000 and if the relocation offset is a multiple > of the maximum alignment requirements of the image. > > The original patch I submitted didn't handle an end condition properly, > was ARM64-specific (wasn't tested on other architectures), and because > the patch was NAK'd, I didn't bother to submit a v2 patch and consider > the idea to be dead. I'm happy to abandon the patch. I hope this helps. Thanks. If I understand correctly, your target has a requirement for storing the image on a 512-byte boundary. But how does this affect the loading of the image into RAM, where the requirement is only that the vectors table be 32-bytes aligned? I mean, if you store the image in MMC at offset 0x200 (thus satisfying the 512-byte boundary requirement) and load it to, say, offset 0x10020 in RAM, how is it a problem for your target? If my example above inadequately represents the issue, then can you please provide a similar but adequate example, a failure case scenario, so that I can hve a correct understanding of the problem? > Best regards, > Darwin Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
