[U-Boot] ide support for linux, doubts about "IDE" and device tree blob
carlojpisani at gmail.com
Wed Oct 9 11:47:05 UTC 2019
I am a bit confused about two things
1) is the "ide" (disk read/write/boot) module intended to be PCI-MEM
"memory-mapped" oriented concerning the harddrive? or is it PCI_IO
oriented? there are too many layers of code and this makes me confused
2) what is the philosophy about initializing the PCI_bridge? and what
is u-boot supposed to do concerning the device-tree-blog to be passed
to the kernel?
there are pieces of code in the kernel source telling me this
* Older u-boots don't set PCI up properly.
* Update the hardware to match the device tree.
* The prefetch mem region and non-prefetch mem region
* must be contiguous in the host bus.
* As required by the PCI binding, PCI #addr/#size must be 3/2.
* The parent bus must be 1/1.
* Only 32-bit PCI is supported.
* All three region types
* prefetchable mem
* non-prefetchable mem
* must be present
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