Linux pci Initialization

1. Function call Sequence

(Gdb) bt

#0 pci_arch_init () at arch/x86/pci/init. c: 13
#1 0xc1001255 in do_one_initcall (fn = 0xc17a3afa <pci_arch_init>) at init/main. c: 758
#2 0xc176c963 in do_initcils (unused = <value optimized out>) at init/main. c: 788
#3 do_basic_setup (unused = <value optimized out>) at init/main. c: 806
#4 kernel_init (unused = <value optimized out>) at init/main. c: 898
#5 0xc1001_e in ?? () At arch/x86/kernel/entry_32.S: 1009
#6 0x00000000 in ?? ()

Static void _ init do_initcils (void)
{
Initcall_t * fn;

For (fn = _ early_initcall_end; fn <_ initcall_end; fn ++)
Do_one_initcall (* fn );
}

The definition in vmlinux. lds is as follows:

_ Early_initcall_end = .; *(. initcall0.init )*(. initcall0s. init )*(. initcall1.init )*(. initcall1s. init )*(. initcall2.init )*(. initcall2s. init )*(. initcall3.init )*(. initcall3s. init )*(. initcall4.init )*(. initcall4s. init )*(. initcall5.init )*(. initcall5s. init)
* (. Initcallrootfs. init) * (. initcall6.init) * (. initcall6s. init) * (. initcall7.init) * (. initcall7s. init) _ initcall_end =.

That is to say, the do_initcils function calls all the Code placed in these sections.

The pci_arch_init function is defined

Static _ init int pci_arch_init (void)
{

}
Arch_initcall (pci_arch_init );

# Define arch_initcall (FN) _ define_initcall ("3", FN, 3)

# DEFINE _ define_initcall (Level, FN, ID )\
Static initcall_t _ initcall _ # FN # ID _ used \
_ Attribute _ (_ Section _ (". initcall" level ". init") = FN

This definition defines the _ initcall_pci_arch_init_init3 function pointer in the section. initcall3.init. Its value is pci_arch_init.