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| -rw-r--r-- | src/supervisor.tex | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/src/supervisor.tex b/src/supervisor.tex index 4a7b5ba..0f5c8bb 100644 --- a/src/supervisor.tex +++ b/src/supervisor.tex @@ -1814,27 +1814,26 @@ have the same meaning as for Sv32. \begin{table}[h] \begin{center} -\begin{tabular}{|c|c||l|} +\begin{tabular}{|c||l|} \hline -C & N & Description \\ +C & Description \\ \hline -0 & 0 & The PTE follows standard address-translation rules \\ -0 & 1 & The PTE follows the rules specified in the Svnapot extension \\ -1 & 0 & {\em Designated for custom use} \\ -1 & 1 & {\em Reserved for standard use} \\ +0 & The PTE follows standard address-translation rules \\ +1 & {\em Designated for custom use} \\ \hline \end{tabular} \end{center} -\caption{Meaning of PTE C and N bits in Sv39.} +\caption{Meaning of PTE C bit in Sv39.} \label{tab:pte_cv_bits} \end{table} -The C and N bits are defined as shown in Table~\ref{tab:pte_cv_bits}. The C -bit is used to indicate that a PTE uses a custom implementation-specific -encoding in the remaining bits other than the V bit. The N bit indicates that -the page represents a naturally-aligned power-of-two range of contiguous -translations, as defined in the Svnapot extension in Chapter~\ref{svnapot}. -Setting the C and N bits simultaneously is reserved for future standard use. +As shown in Table~\ref{tab:pte_cv_bits}, the C bit is used to indicate that a +PTE uses a custom implementation-specific encoding in the remaining bits other +than the V bit. + +If the C bit is not set, the N bit indicates that the page represents a +naturally-aligned power-of-two range of contiguous translations, as defined in +the Svnapot extension in Chapter~\ref{svnapot}. Bits 61--54 are reserved for future standard use and must be zeroed by software for forward compatibility. |