1653db7ddc
With CONFIG_PAGING enabled and the RISC-V SV39 MMU active, the page fault handler incorrectly tracked page table levels: `ptprev` pointed to the L1 page table while `ptlevel` indicated L2. This inconsistency caused faulty virtual address resolution. This commit fixes the traversal logic to ensure consistent level tracking across all three page table levels (L1–L3), enabling reliable page fault handling and on-demand paging. Additional changes: - Set PGT_L3_SIZE to 2048 to enable mapping up to 8MB of address space. - Update knsh_paging config to avoid crashes caused by excessive memory alignment requirements. - Add knsh64_paging config to verify this commit works as expected. Signed-off-by: liang.huang <liang.huang@houmo.ai>
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.