buxiasen
93a2c4d2eb
arm_dispatch_syscall in armv7-m clobbered r11 with 'mov r11, sp' and the user-space callee-saved register value leaked back through the exception frame when SYS_syscall_return restored the context, resulting in corrupted parameters on subsequent syscalls and system hangs in protected builds. In armv6-m, r4 was used to load g_stublookup (Thumb-1 cannot use ip for indexed addressing) but was not restored before SYS_syscall_return, causing the same class of register corruption. Fix with minimal changes: - armv7-m: remove 'mov r11, sp' to stop clobbering user r11 - armv6-m: restore r4 from the stack frame before SYS_syscall_return Signed-off-by: buxiasen <buxiasen@xiaomi.com>
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.