[BUG] U-Boot qemu_arm64_defconfig CONFIG_CUSTOM_SYS_INIT_SP_ADDR collides with TF-A RMM granules

[Yuvraj Sakshith]

Hi folks,

I have been experimenting with ARMv9 on QEMU.

Here is my configuration:
	QEMU (8.2.2)
	TF-A built with ENABLE_RME
	U-Boot in Normal World (qemu_arm64_defconfig) + Linux Kernel Image passed to QEMU
	TF-RMM built into TF-A

As mentioned in arm-trusted-firmware/plat/qemu/include/qemu_pas_def.h, TF-A reserves a region of
24MB starting from 0x40100000 for the RMM in L1 GPTs.

When control switches to normal world, U-Boot sets up its stack to CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x40200000.

During u-boot/arch/arm/lib/crt0_64.S:_main(), control jumps to u-boot/common/init/board_init.c:board_init_f_alloc_reserve().
I am not exactly sure what this method indends to do, but from the comments I understand it carves out some memory for the
"globals". This eventually ends up pushing the stack pointer to 0x401fde70. Which is inside the RMM PAS initialised by TF-A.

Post this, I get a Granule Protection Fault and the machine hangs up.

I wanted to know how this can be fixed and if my configuration is wrong.

Please let me know if there is any extra info that I need to provide for inspection.

R,
Yuvraj Sakshith