Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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22 lines
943 B
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.. SPDX-License-Identifier: GPL-2.0
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DeviceTree Booting
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------------------
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There is one single 32bit entry point to the kernel at code32_start,
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the decompressor (the real mode entry point goes to the same 32bit
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entry point once it switched into protected mode). That entry point
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supports one calling convention which is documented in
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Documentation/arch/x86/boot.rst
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The physical pointer to the device-tree block is passed via setup_data
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which requires at least boot protocol 2.09.
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The type filed is defined as
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#define SETUP_DTB 2
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This device-tree is used as an extension to the "boot page". As such it
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does not parse / consider data which is already covered by the boot
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page. This includes memory size, reserved ranges, command line arguments
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or initrd address. It simply holds information which can not be retrieved
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otherwise like interrupt routing or a list of devices behind an I2C bus.
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