Solve undefined reference to`__ aeabi_ Uidivmod 'and undefined reference to`__ aeabi_ Uidiv 'error

Write your own bare metal driver , Division is used , The following error occurred when linking :

The compiler used is :

Later, I searched the Internet for the reason , Because the compiler does not support division , But no solution was found . After looking at the code, it is really practical to divide , Remove the division and connect normally . Then I thought about it , Before compiling the kernel and compiling u_boot It's all from this compiler , They must have division , How they do it ？

So I took a look u_boot Of Makefile, I feel dizzy , There are so many things , Later, I compiled it , See this :

u_boot At link time , Specifies the path and... Of the yellow color -lgcc Options (-l Next is the name of the link library )

Go to the specified directory and see the following :

There's a libgcc.a Static library , The compiler supports soft floating point , Guess the implementation of soft floating point should be looking for a static library .

In their own Makefile These things are added to it , Continue to compile the connection, and the following error message appears :

The lack of "raise Symbol ", stay u_boot Search in source code "raise" as follows :

It's a function , Nothing , I wrote such an empty function in my code , Compile and pass .

Makefile as follows :

summary :

    ARMv4t Of ARM The core does not support floating-point operations , In order to support floating-point operation , The compiler uses the soft floating-point method , But the corresponding division library support is required , When connecting, you need to specify its path and library name .

    A classic saying : stay IT industry , Have a problem , As long as it is solved all the time , One day it will be solved .