path: root/docs/firmware-design.rst
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authorDavid Cunado <david.cunado@arm.com>2017-10-20 11:30:57 +0100
committerDavid Cunado <david.cunado@arm.com>2017-11-15 22:42:05 +0000
commit91089f360aaa38408d96a02136456dbde4f34eaf (patch)
tree33301c2c73797b1f5ae3582070e314895d2319e1 /docs/firmware-design.rst
parente83769c07bb09b7727a36389c9dd92096860637e (diff)
Move FPEXC32_EL2 to FP Context
The FPEXC32_EL2 register controls SIMD and FP functionality when the lower ELs are executing in AArch32 mode. It is architecturally mapped to AArch32 system register FPEXC. This patch removes FPEXC32_EL2 register from the System Register context and adds it to the floating-point context. EL3 only saves / restores the floating-point context if the build option CTX_INCLUDE_FPREGS is set to 1. The rationale for this change is that if the Secure world is using FP functionality and EL3 is not managing the FP context, then the Secure world will save / restore the appropriate FP registers. NOTE - this is a break in behaviour in the unlikely case that CTX_INCLUDE_FPREGS is set to 0 and the platform contains an AArch32 Secure Payload that modifies FPEXC, but does not save and restore this register Change-Id: Iab80abcbfe302752d52b323b4abcc334b585c184 Signed-off-by: David Cunado <david.cunado@arm.com>
Diffstat (limited to 'docs/firmware-design.rst')
1 files changed, 0 insertions, 1 deletions
diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 7cc197096b..c0ece0ba80 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -1144,7 +1144,6 @@ The sample crash output is shown below.
cntv_ctl_el0 :0x0000000000000000
cntv_cval_el0 :0x0000000000000000
cntkctl_el1 :0x0000000000000000
- fpexc32_el2 :0x0000000004000700
sp_el0 :0x0000000004010780
Guidelines for Reset Handlers