Nightloader/i386/legacy-boot/src-asm/drivers/pci/driver.asm

PCI_CONFIG_ADDRESS_PORT                         equ 0x0cf8
PCI_CONFIG_DATA_PORT                            equ 0x0cfc

PCI_DEVICE_COUNT_OFFSET equ 0xffe
PCI_DEVICE_AREA_OFFSET  equ 0x1000

; [FURTHEST FROM BP]
;   0.  Ptr32           Pointer to 65536B slot for PCI driver
; [NEAREST TO BP]
initialize_pci_driver:
    push        dword                   esi
    sub         esp,                    64
    mov         esi,                    esp

    mov         [esi + (64 - 4)],       eax
    mov         [esi + (64 - 8)],       ebx
    mov         [esi + (64 - 12)],      ecx
    mov         [esi + (64 - 16)],      edx
    mov         [esi + (64 - 20)],      edi

.body:
    mov ebx, [ebp - 4]
    push ebp
    mov ebp, esp
    push ebx
    push dword 0        ; No Maximum Device Limit
    call pci_enumerate
    mov esp, ebp
    pop ebp

    mov ebx, [ebp - 4]
    add ebx, PCI_DEVICE_COUNT_OFFSET

    push ebp
    mov ebp, esp
    push dword PCI_DEVICE_COUNT_OFFSET
    push dword 2
    push dword 0
    push dword 0
    call write_hexadecimal_string
    mov esp, ebp
    pop ebp

    ; todo(wip): Remove this once the PCI Driver
    ;            is debugged completely.

    cli
    hlt

.epilog:
    mov         eax,                    [esi + (64 - 4)]
    mov         ebx,                    [esi + (64 - 8)]
    mov         ecx,                    [esi + (64 - 12)]
    mov         edx,                    [esi + (64 - 16)]
    mov         edi,                    [esi + (64 - 20)]

    add         esp,                    64
    pop         dword                   esi
    ret
.storage:
    dd 0

%include "drivers/pci/enumerate.asm"