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diff --git a/Documentation/riscv/uabi.rst b/Documentation/riscv/uabi.rst deleted file mode 100644 index 8960fac42c..0000000000 --- a/Documentation/riscv/uabi.rst +++ /dev/null @@ -1,48 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -RISC-V Linux User ABI -===================== - -ISA string ordering in /proc/cpuinfo ------------------------------------- - -The canonical order of ISA extension names in the ISA string is defined in -chapter 27 of the unprivileged specification. -The specification uses vague wording, such as should, when it comes to ordering, -so for our purposes the following rules apply: - -#. Single-letter extensions come first, in canonical order. - The canonical order is "IMAFDQLCBKJTPVH". - -#. All multi-letter extensions will be separated from other extensions by an - underscore. - -#. Additional standard extensions (starting with 'Z') will be sorted after - single-letter extensions and before any higher-privileged extensions. - -#. For additional standard extensions, the first letter following the 'Z' - conventionally indicates the most closely related alphabetical - extension category. If multiple 'Z' extensions are named, they will be - ordered first by category, in canonical order, as listed above, then - alphabetically within a category. - -#. Standard supervisor-level extensions (starting with 'S') will be listed - after standard unprivileged extensions. If multiple supervisor-level - extensions are listed, they will be ordered alphabetically. - -#. Standard machine-level extensions (starting with 'Zxm') will be listed - after any lower-privileged, standard extensions. If multiple machine-level - extensions are listed, they will be ordered alphabetically. - -#. Non-standard extensions (starting with 'X') will be listed after all standard - extensions. If multiple non-standard extensions are listed, they will be - ordered alphabetically. - -An example string following the order is:: - - rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux - -Misaligned accesses -------------------- - -Misaligned accesses are supported in userspace, but they may perform poorly. |