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| author | Andrew Waterman <andrew@sifive.com> | 2024-01-28 16:14:25 -0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-01-28 16:14:25 -0800 |
| commit | 86ff22d64be34bf880290f74b57190a7d3bca0f1 (patch) | |
| tree | f4f85a7aa9c1594859ecc979cf923ffa3073d824 /src/priv-preface.adoc | |
| parent | 72ff2f6468c7f7de209ce7e037a5303a18235ce6 (diff) | |
| parent | 9a7dd2fe29011587954560b5dcf1875477b27ad8 (diff) | |
| download | riscv-isa-manual-86ff22d64be34bf880290f74b57190a7d3bca0f1.zip riscv-isa-manual-86ff22d64be34bf880290f74b57190a7d3bca0f1.tar.gz riscv-isa-manual-86ff22d64be34bf880290f74b57190a7d3bca0f1.tar.bz2 | |
Merge pull request #1204 from riscv/mxl-read-only
Redefine MXL to be read-only
Diffstat (limited to 'src/priv-preface.adoc')
| -rw-r--r-- | src/priv-preface.adoc | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/priv-preface.adoc b/src/priv-preface.adoc index 5e857d9..ff153ce 100644 --- a/src/priv-preface.adoc +++ b/src/priv-preface.adoc @@ -31,7 +31,14 @@ _Draft_ + *Ratified* |=== -The following compatible changes have been made to the Machine ISA since +The following changes have been made since version 1.12, which, while +not strictly backwards compatible, are not anticipated to cause software +portability problems in practice: + +* Redefined `misa`.MXL to be read-only, making MXLEN a constant. +* Added the constraint that SXLEN≥UXLEN. + +Additionally, the following compatible changes have been made to the Machine ISA since version 1.12: * Transliterated the document from LaTeX into AsciiDoc. @@ -44,8 +51,7 @@ in `menvcfg` and `henvcfg`. * Clarified that "platform- or custom-use" interrupts are actually "platform-use interrupts", where the platform can choose to make some custom. * Clarified semantics of explicit accesses to CSRs wider than XLEN bits. -* Clarified that MXLEN≥SXLEN, and added the constraint that -SXLEN≥UXLEN. +* Clarified that MXLEN≥SXLEN. * Clarified that WFI is not a HINT instruction. * Clarified that VS-stage page-table accesses set G-stage A/D bits. * Clarified ordering rules when PBMT=IO is used on main-memory regions. |