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author | Andrew Waterman <andrew@sifive.com> | 2018-11-27 15:13:26 -0800 |
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committer | Andrew Waterman <andrew@sifive.com> | 2018-11-27 15:16:04 -0800 |
commit | c7a81b2be5e210da2134b29aeb8e0fda1893cedd (patch) | |
tree | 2e0bfeda63441dbd573ad2c901d09e3a3f04e1a2 /src/machine.tex | |
parent | 83a0c2261cec419415f1e7c37c07479f79613185 (diff) | |
download | riscv-isa-manual-c7a81b2be5e210da2134b29aeb8e0fda1893cedd.zip riscv-isa-manual-c7a81b2be5e210da2134b29aeb8e0fda1893cedd.tar.gz riscv-isa-manual-c7a81b2be5e210da2134b29aeb8e0fda1893cedd.tar.bz2 |
Misc. address translation clarifications
Courtesy @gameboo in #205
Diffstat (limited to 'src/machine.tex')
-rw-r--r-- | src/machine.tex | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/machine.tex b/src/machine.tex index 1768a5c..8f7ab7e 100644 --- a/src/machine.tex +++ b/src/machine.tex @@ -638,13 +638,13 @@ widest supported width not wider than the new MXLEN. \subsection{Memory Privilege in {\tt mstatus} Register} -The MPRV (Modify PRiVilege) bit modifies the privilege level at which -loads and stores execute in all privilege modes. When MPRV=0, -translation and protection behave as normal. When MPRV=1, load and -store memory addresses are translated and protected as though the -current privilege mode were set to MPP. Instruction -address-translation and protection are unaffected. MPRV is hardwired -to 0 if U-mode is not supported. +The MPRV (Modify PRiVilege) bit modifies the privilege level at which loads +and stores execute in all privilege modes. When MPRV=0, loads and stores +behave as normal, using the translation and protection mechanisms of the +current privilege mode. When MPRV=1, load and store memory addresses are +translated and protected as though the current privilege mode were set to MPP. +Instruction address-translation and protection are unaffected by the setting +of MPRV. MPRV is hardwired to 0 if U-mode is not supported. The MXR (Make eXecutable Readable) bit modifies the privilege with which loads access virtual memory. When MXR=0, only loads from pages marked readable (R=1 |