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From: cinap_lenrek@felloff.net
To: 9front@9front.org
Subject: Re: [9front] PXE booting Rpi
Date: Thu, 08 Apr 2021 16:21:24 +0200	[thread overview]
Message-ID: <C29503CCF8278A13D18E31A9E975356E@felloff.net> (raw)
In-Reply-To: <B5B48522-4D77-45DE-A2DD-FE29EB0B3258@me.com>

you have to distinguish the bcm and bcm64 kernels.

in bcm64, a arm64 kernel, device tree is passed in R0.

the devicetree support was implemented for raspberry pi 4 as the
newer firmware didnt provide atags. and we also need devicetree
now as they move the pci windows around in physical memory depending
on the model (cm4, pi400).

in the 32 bit bcm kernel, the ATAGS where always located at a fixed
memory location 0x100. devicetree was not used. it is possible
that this assumption doesnt hold anymore and now atags are at
a variable address passed in R2 as you say?

note, i didnt come up with this logic. and didnt pay too much
attention on the 32 bit bcm kernels and their newer firmware
incarnations.

it might be confusinbg as bcm/bootargs.c is shared between
the bcm and bcm64 kernels.

--
cinap

  reply	other threads:[~2021-04-08 14:28 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-10 14:05 Daniel Morandini
2021-03-10 17:20 ` cinap_lenrek
2021-03-12 10:36   ` Daniel Morandini
2021-03-25 10:55     ` Daniel Morandini
2021-03-25 18:49       ` Noam Preil
2021-03-25 21:49         ` Noam Preil
2021-04-07  8:39         ` Daniel Morandini
2021-04-08 14:21           ` cinap_lenrek [this message]
2021-04-08 15:45             ` Daniel Morandini
2021-04-08 16:12               ` cinap_lenrek
2021-04-11 12:11                 ` cinap_lenrek
2021-04-12  9:04                   ` Daniel Morandini
2021-04-12 10:14                     ` cinap_lenrek
2021-04-12 16:48                       ` Daniel Morandini
2021-04-15 21:15                         ` cinap_lenrek
2021-04-19  7:53                           ` Daniel Morandini
2021-04-19 16:20                             ` Daniel Morandini

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