On Monday 09 June 2008, Frank Wei wrote:
I'm new to u-boot. Has anybody tried to make 2-step u-boot? I mean a really small u-boot (the first u-boot) possible only needs to initialize the CPU, memory... and load the full featured (the second u-boot) u-boot and the Linux to the RAM. In this way the second u-boot as an application can be updated on the fly.
Could you please share your knowledge here If you have done the job or the similar?
Yes, there already is a framework for a 2-stage U-Boot booting in place. Take a look at the nand_spl (NAND Secondary Program Loader) infrastructure:
nand_spl/* doc/README.nand-boot-ppc440
Here a small (4k) image is build which only inits the basic CPU stuff, RAM and NAND controller. Then a full-blown U-Boot image is loaded from NAND.
Best regards, Stefan
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