Re: [PATCH 1/2] socfpga: correct start vector when not using extra barebox header

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, May 20, 2016 at 11:09:59PM +0000, Trent Piepho wrote:
> The barebox ARM image has a 0x50 byte header that consists of:
> Bytes 0x00 - 0x0a:  Instruction(s) to jump to start of code
> Bytes 0x20 - 0x2f:  Signature and some other data
> The rest of header is basically padding.
> 
> On SocFPGA, the ROM bootloader expects the 2nd stage bootloader
> (barebox) to have a 0x40 byte header with the following fields:
> Bytes 0x40 - 0x4b:  Signature and some other data
> Bytes 0x4c - 0x4f:  Instruction to jump to start of code
> 
> These two headers are compatible, as everything defined in the SocFPGA
> header is at a location that is padding the barebox header.
> 
> socfpga_mkimage has two methods for creating a SocFPGA image.  One method
> prepends an extra 512 byte header to the barebox image, which contains the
> SoCFPGA header described above.  The start vector at 0x4c is hard coded to
> jump to offset 512, where the barebox header's start vector will be.
> 
> socfpga_mkimage can also not prepend this additional header and instead
> modify the barebox header to be SoCFPGA compatible.  But it only writes
> bytes 0x40-0x4b and not the start vector at 0x4c, leaving that word as
> padding.  And so this image will not boot when the ROM bootloader runs it.
> 
> This changes the SoCFPGA header creator to write a correct start vector for
> both methods.  It will create a branch instruction at 0x4c that jumps to the
> start of the barebox image, whether it be at offset 0 or offset 512 (or any
> other location).
> 
> This makes SoCFPGA images without the extra header bootable.
> ---
>  scripts/socfpga_mkimage.c | 29 +++++++++++++++++++++--------
>  1 file changed, 21 insertions(+), 8 deletions(-)

Applied both, thanks

Sascha


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