abbfb31a02
up_addrenv_va_to_pa() is declared in include/nuttx/arch.h but implemented only by armv7-a, so no arm64 port can map a virtual address to a physical one. A driver whose device addresses memory physically has nothing to call. The translation is asked of the MMU with AT S1E1R rather than walked in software, so it answers for whatever is actually mapped: any granule size, block or page, at any level, and it cannot drift from the tables in use. PAR_EL1 is one register per CPU, so nothing may run between the translation and reading the result. Interrupts are banked with it, so masking them locally is sufficient and SMP needs nothing further. Returns zero for an address that is not mapped for a privileged read, which is what the declaration in arch.h specifies. Note this differs from the armv7-a implementation, which returns the virtual address unchanged. Signed-off-by: Royyan Zahir <royzah@gmail.com> |
||
|---|---|---|
| .github | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
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.