The structures are available in the apps space but not kernel space,
unless you include a convoluted path to get from the board directory
(out-of-tree in my case). I have been trying to include to my board
stuff as I thought that's were it would belong, consistent with other
image boot, arch-specific functions. The file is not in the usual
apps/include directory: it is a sub-directory of the nxboot app
directory, so I was think to split it so not everything in the current
nxboot.h needs to be available to the kernel space, just the minimum.
But still needs a "../.." type header inclusion which is not nice.
Karel emailed me (direct, not to list: perhaps just a mistake) saying:
if you are trying to implement image loading to RAM by bootloader I
would suggest you to think about adding this mode possibly to the NXBoot itself.
Our use case (me and Michal Lenc) is to boot image from program flash and
perform update over external storage (such as SPI NOR); thus loading to RAM is
not provided at the moment. But if implemented correctly it could make sense to
have loading to RAM as well.
My use case is similar but different: I have a partitioned NOR-flash
that has the 3x NXboot slots. An update would usually be via the "user
app" to get the new image into a specific "slot" partition...but I am
also looking at the worst case, of when an upgrade goes horribly wrong
and the user needs to recover somehow. I am also in the process of
developing an option for NXboot to call an external handler in this
situation to allow prompts to the user to insert USB sticks or whatever.
I will do this as an "example app" to demonstrate the principle.
If I was to add "load to RAM" to NXboot that would probably be a
good/better thing. But I don't know how generic that could be, across
many many architectures. I'll have to ponder that - took me a while to
get the right assembly code for my arch (SAMA5D2). I may need to think
laterally here!
On 29/04/2025 20:24, Michal Lenc wrote:
Hi Tim,
If I remember correctly, these structures are public now, you should
be able to include <nxboot.h> from your application.
Best regards,
Michal
On 4/29/25 19:48, Tim Hardisty wrote:
I am adding enhancements to my custom image booting software (that
copies the image from flash to internal SDRAM).
As part of that I would like, via PR, to expose /struct
nxboot_img_header/ and it's associated /struct nxboot_hdr_version/
and /struct nxboot_img_version/ via a public header file
(apps/include/nxboot/nxboot.h).
It will allow me to get the actual image size for copying rather than
the entire "slot" size, as well as to be able to extract the image
version information for use by my app.
Can anyone see any problems with this?
