[Buildroot] [PATCH v2 0/2] Linux as BL33 in TF-A

[Jakob Kastelic]

This patch series allows one to run Linux directly from Arm Trusted Firmware
(TF-A) without U-Boot or another SPL (sometimes referred to as "falcon mode").

In my original submission, the patch introduced the new TF-A build option.
Arnout Vandecappelle suggested to also include a Qemu-based defconfig in which
this new flag can be tested. This patch series also includes the new defconfig.

Note that TF-A documentation talks about a ARM_LINUX_KERNEL_AS_BL33 option which
is intended for a similar purpose. However, on AArch32, that flag can only be
used with SP_MIN, which is not supported on all platforms. (For example, in the
present defconfig we use OP-TEE.)

The new flag applies only to AArch32 since I do not have a means of testing it
on AArch64.

For a consideration of alternative approaches, refer to the write-up here:
https://embd.cc/linux-tfa-bl33-qemu

Jakob Kastelic (2):
  boot/arm-trusted-firmware: optional Linux as BL33
  configs/qemu_arm_vexpress_tz_falcon_defconfig: new

 DEVELOPERS                                    |  3 ++
 .../qemu/arm-vexpress-tz-falcon/patch-dts.sh  | 21 +++++++++++
 board/qemu/arm-vexpress-tz-falcon/readme.txt  | 28 +++++++++++++++
 boot/arm-trusted-firmware/Config.in           | 21 +++++++++++
 .../arm-trusted-firmware.mk                   |  8 +++++
 configs/qemu_arm_vexpress_tz_falcon_defconfig | 36 +++++++++++++++++++
 6 files changed, 117 insertions(+)
 create mode 100755 board/qemu/arm-vexpress-tz-falcon/patch-dts.sh
 create mode 100644 board/qemu/arm-vexpress-tz-falcon/readme.txt
 create mode 100644 configs/qemu_arm_vexpress_tz_falcon_defconfig

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2.39.5