modify the prototype of up_putc(): remove the return value
The architecture code does not care about the return value of up_putc(), so removing it saves two statements:
Before: After:
de4c: e52de004 push {lr} @ (str lr, [sp, #-4]!) | de4c: e52de004 push {lr} @ (str lr, [sp, #-4]!)
de50: e24dd014 sub sp, sp, #20 | de50: e24dd014 sub sp, sp, #20
de54: e58d0004 str r0, [sp, #4] | de54: e58d0004 str r0, [sp, #4]
de58: e30030f8 movw r3, #248 @ 0xf8 | de58: e30030f8 movw r3, #248 @ 0xf8
de5c: e3423000 movt r3, #8192 @ 0x2000 | de5c: e3423000 movt r3, #8192 @ 0x2000
de60: e58d300c str r3, [sp, #12] | de60: e58d300c str r3, [sp, #12]
de64: e59d1004 ldr r1, [sp, #4] | de64: e59d1004 ldr r1, [sp, #4]
de68: e59d000c ldr r0, [sp, #12] | de68: e59d000c ldr r0, [sp, #12]
de6c: ebfffe66 bl d80c <pl011_putc> | de6c: ebfffe66 bl d80c <pl011_putc>
de70: e59d3004 ldr r3, [sp, #4] | de70: e28dd014 add sp, sp, #20
de74: e1a00003 mov r0, r3 | de74: e49df004 pop {pc} @ (ldr pc, [sp], #4)
de78: e28dd014 add sp, sp, #20 |
de7c: e49df004 pop {pc} @ (ldr pc, [sp], #4) |
Signed-off-by: chao an <anchao@lixiang.com>
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| .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 | ||
| .gitignore | ||
| .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.