sonicyang opened a new pull request #973: URL: https://github.com/apache/incubator-nuttx/pull/973
## Summary If the user chooses to enable SSE related function in config, the OS will check and initialize the FPU during boot. During the setup of FPU, the LDMXCSR instruction takes a 32 bit memory address, containing the FPU setting. The FPU setting is hardcoded and placed in the binary image. However, this is conducted after the kernel's lower memoey mapping was revoked, causing a page fault. Using the high address of the hardcoded FPU setting is not possible because the kernel is mapped above 4GB space (32bit). The proposed fix it by revoking the lower 128MB mapping at a later stage of booting, after the setup procedure is conducted. ## Impact No more instant crash during boot with SSE/AVX enabled. ## Testing Should boot on bochs/qemu with ostest ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
