ff4e6c35c9
Our fdtw_read_cells() implementation goes to great lengths to sanity-check every parameter and result, but leaves a big hole open: The size of the storage the value pointer points at needs to match the number of cells given. This can't be easily checked at compile time, since we lose the size information by using a void pointer. Regardless the current usage of this function is somewhat wrong anyways, since we use it on single-element, fixed-length properties only, for which the DT binding specifies the size. Typically we use those functions dealing with a number of cells in DT context to deal with *dynamically* sized properties, which depend on other properties (#size-cells, #clock-cells, ...), to specify the number of cells needed. Another problem with the current implementation is the use of ambiguously sized types (uintptr_t, size_t) together with a certain expectation about their size. In general there is no relation between the length of a DT property and the bitness of the code that parses the DTB: AArch64 code could encounter 32-bit addresses (where the physical address space is limited to 4GB [1]), while AArch32 code could read 64-bit sized properties (/memory nodes on LPAE systems, [2]). To make this more clear, fix the potential issues and also align more with other DT users (Linux and U-Boot), introduce functions to explicitly read uint32 and uint64 properties. As the other DT consumers, we do this based on the generic "read array" function. Convert all users to use either of those two new functions, and make sure we never use a pointer to anything other than uint32_t or uint64_t variables directly. This reveals (and fixes) a bug in plat_spmd_manifest.c, where we write 4 bytes into a uint16_t variable (passed via a void pointer). Also we change the implementation of the function to better align with other libfdt users, by using the right types (fdt32_t) and common variable names (*prop, prop_names). [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi#n874 [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/ecx-2000.dts Change-Id: I718de960515117ac7a3331a1b177d2ec224a3890 Signed-off-by: Andre Przywara <andre.przywara@arm.com> |
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| plat | ||
| services | ||
| tools | ||
| .checkpatch.conf | ||
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| license.rst | ||
| readme.rst | ||
readme.rst
Trusted Firmware-A
Trusted Firmware-A (TF-A) is a reference implementation of secure world software for Arm A-Profile architectures (Armv8-A and Armv7-A), including an Exception Level 3 (EL3) Secure Monitor. It provides a suitable starting point for productization of secure world boot and runtime firmware, in either the AArch32 or AArch64 execution states.
TF-A implements Arm interface standards, including:
- Power State Coordination Interface (PSCI)
- Trusted Board Boot Requirements CLIENT (TBBR-CLIENT)
- SMC Calling Convention
- System Control and Management Interface (SCMI)
- Software Delegated Exception Interface (SDEI)
The code is designed to be portable and reusable across hardware platforms and software models that are based on the Armv8-A and Armv7-A architectures.
In collaboration with interested parties, we will continue to enhance TF-A with reference implementations of Arm standards to benefit developers working with Armv7-A and Armv8-A TrustZone technology.
Users are encouraged to do their own security validation, including penetration testing, on any secure world code derived from TF-A.
More Info and Documentation
To find out more about Trusted Firmware-A, please view the full documentation that is available through trustedfirmware.org.
Copyright (c) 2013-2019, Arm Limited and Contributors. All rights reserved.