path: root/plat/rpi
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authorAndre Przywara <andre.przywara@arm.com>2019-07-22 00:04:40 +0100
committerAndre Przywara <andre.przywara@arm.com>2019-09-25 11:45:35 +0100
commit2b19e2f361ac9be69f0f19ed7a25b1a038d91fc3 (patch)
tree53adea83023fdf64de110658e36ff616f6d0b574 /plat/rpi
parentf67fa69cb6937a7fc559bbec4a7acce5edefa888 (diff)
rpi4: Reserve resident BL31 region from non-secure world
The GPU firmware loads the armstub8.bin (BL31) image at address 0, the beginning of DRAM. As this holds the resident PSCI code and the SMP pens, the non-secure world should better know about this, to avoid accessing memory owned by TF-A. This is particularly criticial as the Raspberry Pi 4 does not feature a secure memory controller, so overwriting code is a very real danger. Use the newly introduced function to add a node into reserved-memory node, where non-secure world can check for regions to be excluded from its mappings. Reserve the first 512KB of memory for now. We can refine this later if need be. Change-Id: I00e55e70c5c02615320d79ff35bc32b805d30770 Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Diffstat (limited to 'plat/rpi')
1 files changed, 4 insertions, 0 deletions
diff --git a/plat/rpi/rpi4/rpi4_bl31_setup.c b/plat/rpi/rpi4/rpi4_bl31_setup.c
index e1b6c89764..8dfadf7306 100644
--- a/plat/rpi/rpi4/rpi4_bl31_setup.c
+++ b/plat/rpi/rpi4/rpi4_bl31_setup.c
@@ -245,6 +245,10 @@ static void rpi4_prepare_dtb(void)
+ /* Reserve memory used by Trusted Firmware. */
+ if (fdt_add_reserved_memory(dtb, "atf@0", 0, 0x80000))
+ WARN("Failed to add reserved memory nodes to DT.\n");
ret = fdt_pack(dtb);
if (ret < 0)
ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);