所有错误及警告文档：Documentation – Arm Developer
优先在arm官网搜索官方回答：https://developer.arm.com/documentation/

错误ERROR

ERROR L104: MULTIPLE PUBLIC DEFINITIONS

  1. *** ERROR L104: MULTIPLE PUBLIC DEFINITIONS
  2.     SYMBOL:  UART_CONFIG
  3.     MODULE:  .\Objects\Buzzer.obj (BUZZER)

重复定义的公共函数或变量，全局搜索提示给的UART_CONFIG，看哪里重复了，改个名字，或加个static

警告WARNING

WARNING L7: MODULE NAME NOT UNIQUE

  1. *** WARNING L7: MODULE NAME NOT UNIQUE
  2.     MODULE:  .\Objects\Conf_tny.obj (?RTX51_TINY_KERNAL)

模块名不唯一，多个模块中声明了相同的模块名。或是对模块编译顺序进行调整。本例是关于?RTX51_TINY_KERNAL的变异警告，可以将Conf_tny.A51文件所在目录OS提到最上边即可。（也可直接删掉OS目录及模块）
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WARNING L15: MULTIPLE CALL TO SEGMENT

  1. *** WARNING L15: MULTIPLE CALL TO SEGMENT
  2.     SEGMENT: ?PR?PRINTF?PRINTF
  3.     CALLER1: ?PR?BR_UART2?MAIN
  4.     CALLER2: ?PR?ULTRASONIC?MAIN

多处调用代码块警告，忽略即可：
Options for Target ->BL51 Misc -> Warnings|Disable Warning Numbers 添加15，多个忽略Number用逗号,分隔

WARNING L16: UNCALLED SEGMENT

  1. *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS
  2.     SEGMENT: ?PR?_PRINTSTRING1?UART

有声明的函数未调用，忽略即可：
Options for Target ->BL51 Misc -> Warnings|Disable Warning Numbers 添加16，多个忽略Number用逗号,分隔
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