[U-Boot] passing board description structure when loading OS image

Wolfgang Denk wd at denx.de
Mon Sep 8 22:27:56 CEST 2014


Dear Ivan,

In message <CAF10W3y1mYmnqMeWRAJzEogoaayNGkHTbakCT7LZ2qrjtJvLEA at mail.gmail.com> you wrote:
> 
> Is there any special reason to not pass the board description
> structure to OS when loading OS image ? u-boot does not pass

Passing a binary data structure like bd_t is an extremely ugly, error
prone and risky way to transfer information between independent
software units.  This design originates from v2.2 PPC Linux kernels,
i. e. way over 15 years ago.  It was broken by then (but was the nly
thing we had), and there is zero reason to use it nowadays.

> bd_t pointer to any images not loaded with "bootm". We cannot
> convert our image to u-boot format and we want to access board
> description structure. Could you please say if there are any options
> to get bd_t except for direct u-boot patching ?

Such hardware related information should be passed in the device tree.

Best regards,

Wolfgang Denk

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