From 734704f4a71eb0f50f806ea4cfc103b0af06f28e Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Thu, 20 Feb 2020 17:14:43 +0000 Subject: [PATCH] clarify branches and functions in namespaces --- openpower.mdwn | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/openpower.mdwn b/openpower.mdwn index 6dd224dc4..4c39acd70 100644 --- a/openpower.mdwn +++ b/openpower.mdwn @@ -56,6 +56,21 @@ from OpenPower Foundation. This will allow extending ISA (see ISAMUX/NS) in a clean fashion (including for and by OpenPower Foundation) +## Branches in namespaces + +Branches are fine as it is up to the compiler to decide whether to let the +ISAMUX/NS/escape-sequence countdown run out. + +This is all a software / compiler / ABI issue. + +## Function calls in namespaces + +Storing and restoring the state of the page/subpage CSR should be done by the caller. Or, again, let the countdowns run out. + +If certain alternative configs are expected, they are part of the function ABI which must be spec'd. + +All of this is a software issue (compiler / ABI). + # Compressed, 48, 64, VBLOCK TODO investigate Power VLE (Freescale doc Ref 314-68105) @@ -90,21 +105,6 @@ Store activation length in a CSR. Requirements are to have one instruction in each subpage which resets all the way back to PowerISA default. The other is a "back up stack by 1". -# Branches - -Branches are fine as it is up to the compiler to decide whether to let the -ISAMUX/NS/escape-sequence countdown run out. - -This is all a software / compiler / ABI issue. - -# Function calls. - -Storing and restoring the state of the page/subpage CSR should be done by the caller. Or, again, let the countdowns run out. - -If certain alternative configs are expected, they are part of the function ABI which must be spec'd. - -All of this is a software issue (compiler / ABI). - # RISCV userspace Dual ISA, RV userspace only. Requires PowerISA to be able to context-switch RV registers and CSRs. -- 2.30.2