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https://github.com/brain-hackers/u-boot-brain
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22191ac353
After enabling TrustZone various parts of the CAAM silicon become inaccessible to non TrustZone contexts. The job-ring registers are designed to allow non TrustZone contexts like Linux to still submit jobs to CAAM even after TrustZone has been enabled. The default job-ring permissions after the BootROM look like this for job-ring zero. ms=0x00008001 ls=0x00008001 The MS field is JRaMIDR_MS (job ring MID most significant). Referring to "Security Reference Manual for i.MX 7Dual and 7Solo Applications Processors, Rev. 0, 03/2017" section 8.10.4 we see that JROWN_NS controls whether or not a job-ring is accessible from non TrustZone. Bit 15 (TrustZone) is the logical inverse of bit 3 hence the above value of 0x8001 shows that JROWN_NS=0 and TrustZone=1. Clearly then as soon as TrustZone becomes active the job-ring registers are no longer accessible from Linux, which is not what we want. This patch explicitly sets all job-ring registers to JROWN_NS=1 (non TrustZone) by default and to the Non-Secure MID 001. Both settings are required to successfully assign a job-ring to non-secure mode. If a piece of TrustZone firmware requires ownership of job-ring registers it can unset the JROWN_NS bit itself. This patch in conjunction with a modification of the Linux kernel to skip HWRNG initialisation makes CAAM usable to Linux with TrustZone enabled. Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Peng Fan <peng.fan@nxp.com> Cc: Alex Porosanu <alexandru.porosanu@nxp.com> Cc: Ruchika Gupta <ruchika.gupta@nxp.com> Cc: Aneesh Bansal <aneesh.bansal@nxp.com> Link: https://github.com/OP-TEE/optee_os/issues/1408 Link: https://tinyurl.com/yam5gv9a Tested-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> |
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| .. | ||
| desc_constr.h | ||
| desc.h | ||
| error.c | ||
| fsl_blob.c | ||
| fsl_hash.c | ||
| fsl_hash.h | ||
| fsl_rsa.c | ||
| jobdesc.c | ||
| jobdesc.h | ||
| jr.c | ||
| jr.h | ||
| Kconfig | ||
| Makefile | ||
| rsa_caam.h | ||
| sec.c | ||