kumquat-buildroot/board/qemu/arm-vexpress-tz/linux.fragment

### Enable OP-TEE
CONFIG_TEE=y
CONFIG_OPTEE=y
configs/qemu_arm_vexpress_tz: Armv7-A emulation with TrustZone services This change introduces a Qemu board for an Armv7-A target executing with OP-TEE secure world services. The target Linux based normal world embeds the standard minimal filesystem with OP-TEE non-secure components embedded files from OP-TEE test, examples and benchmark packages. qemu_arm_vexpress_tz_defconfig differs from qemu_arm_vexpress_defconfig. Supporting both secure and non-secure worlds on the Arm target mandates a secure world, here OP-TEE OS, and a bootloader to boot both worlds, here TF-A (boot/arm-trusted-firmware). Here non-secure Linux kernel is booted through U-boot TF-A bootloader (BL1/BL2) => OP-TEE (BL32) => U-boot (BL33). \| Executes as secure \| Secure \| Execs as Non-secure \| Loads BL32/BL33 in RAM \| Jumps to BL33 \| Always booted after \| Jumps to BL32 once done \| as Non-secure \| secure world inits Vexpress and vexpress-tz defconfigs also differs in that Qemu emulates a Cortex-A9 in the former and a Cortex-A15 in the later. Cortex-A15 is the Armv7-A CPU used in upstream TF-A and OP-TEE OS packages hence selected here. Defconfig adds a fragment to the Linux kernel native configuration to enable OP-TEE driver support. Defconfig adds a fragment to the U-Boot native configuration set boot command, enable semihosting and remove U-Boot persistent environment storage support. The defconfig also enables build of the Qemu emulator in case the system installed Qemu does not yet support CPU TrustZone secure state. Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org> [Arnout, with the help of Peter: correct spelling mistakes in readme, fix U-Boot version to 2019.01, download tarball of TF-A instead of git] Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> 2019-03-22 10:58:16 +01:00			`### Enable OP-TEE`
			`CONFIG_TEE=y`
			`CONFIG_OPTEE=y`