Git会忽略所有文件，除了子目录中的某些文件

Question

I'm developing some source codes in ASM but I don't want to save the binaries and obj files, all folders are a new "projects", everything is ok but when I made some changes in Ubuntu not take any changes. Eg.

/
  |- HelloWorld/
    |- hello.asm
    |- hello.o
    |- hello
  |- SomeProject/
    |- some.asm
    |- some.o
    |- some
  |- CProject/
    |- project.c
    |- project.o
    |- project

My .gitignore is:

# Ignore all ASM Binaries
*

# Except source codes files in root
!*.c
!*.asm
!*.sh
!*.gitignore
!*.md
!*.txt
# And source code files in subdirectories
!**/*.c
!**/*.asm
!**/*.sh
!**/*.gitignore
!**/*.md
!**/*.txt

Also tried:

!*/*.txt
!/**/*.txt
!/*/*.txt
!**/*.txt

Answer 1

Resolved, .gitignore:

# Ignore all files
*

# Ignore all files in subdirectories
#**/**

# Unignore all with extensions
!*.*

# Unignore all files in subdirectories
/*
!/*.asm
!/*.c
!/*.sh
!/*.md
!/*.txt
!/*/
/*/**

!/**/*.asm
!/**/*.c
!/**/*.sh
!/**/*.md
!/**/*.txt

# Except source code files
!.gitignore
!*.readme
!*.c
!*.asm
!*.sh
!*.md
!*.txt