Graphics driver programming - static address
============================================

With this example, you can write a static memory address driver, which 
greatly simplifies driver programming. You just need to check that driver 
address at rbp matches the assembled base address.

Enable driver_development in config.mnt to load non-certified drivers.

Graphics driver parameters at config.mnt:

graphics_driver            = Drivers filename
graphics_driver_init       = 0/1 = No/Yes
graphics_boot_set          = 0/1 = Vesa/Driver
graphics_boot_x            = X resolution for driver
graphics_boot_y            = Y resolution for driver
graphics_boot_hz           = Frequency for driver

General driver steps:

1) Kernel loads driver (config.mnt/graphics_driver)
2) If graphics_driver_init = 1, kernel scans PCI for matching 
   device ID's from drivers header.
3) If PCI match is found, kernel executes driver_entry functions 1 and 2.
   If graphics_boot_set = 1 and graphics_driver_init = 1, 
   kernel also executes driver_entry function 4 with x, y and hz parameters.
4) During OS execution, kernel calls functions 1-5 when needed.

Driver is executed at ring-0 privelidge level.
Functions 0-31 are reserved, others available for other use.
If needed, set page non-cacheable with system call 400.

Driver memory consists of two 2MB pages. First page for code and internal
driver data, the second page for data communication between driver and device.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;;  PCI graphics card driver for MenuetOS
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

driver_base equ (0x100000*64)

use64

    org   driver_base

    db    'MENUET64'              ; Header
    dq    0x103                   ; PCI Graphics driver
    dq    driver_entry-driver_base; Driver entry
    dq    image_end               ; Size of image
    dq    image_end               ; Required memory (max 4mb)

    dd    0x11111111              ; Supported PCI card 1
    dd    0x22222222              ; Supported PCI card 2, ..
    dd    0x00000000              ; End

    db    "Newcard interface",0   ; Device
    db    "Newco",0               ; Manufacturer

    inbytes:   dq  0x0            ; Received bytes
    outbytes:  dq  0x0            ; Sent bytes
    status:    dq  0x0            ; 0x00 = driver not initialized
                                  ; 0x01 = device is working properly
                                  ; 0xff = undefined error


driver_entry:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Description : Driver entry from OS.
;
;   In : rax   1 - Init
;              2 - Reset
;              3 - Get all modes
;              4 - Set mode
;              5 - Get current mode
;
;        rbp - Driver location in linear memory
;        r13 - PCI position [pci_bus] shl 16 + [pci_dev] shl 8
;        r14 - Entry point for drivers internal system calls 5,105,400
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    cmp   rbp , driver_base
    je    addressfine
    mov   [status],dword 0xff
    mov   rax , 0xff
    ret
  addressfine:  

    cmp  rax , 1
    je   card_init
    cmp  rax , 2
    je   card_reset
    cmp  rax , 3
    je   card_get_all
    cmp  rax , 4
    je   card_set_mode
    cmp  rax , 5
    je   card_get_mode

    mov  rax , 0xff  ; function not supported

    ret


card_init:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Init driver
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    ; If needed, set next 2M page non-cacheable with system call 400
    ; for data transfer to the device

;    mov   rax , 400
;    mov   rbx , 1
;    mov   rcx , driver_base+0x100000*2
;    call  r14 ; syscall entry

    ; Success
    
    mov   [status],dword 1    
    mov   rbx , 11111b  ; bitfield - supported functions
    mov   rax , 0       

    ret

    ; Fail

    mov   [status],dword 0xff
    mov   rbx , 0
    mov   rax , 1      

    ret



card_reset:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Init driver
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   
    mov   rax , 0     ; 0=success
    mov   rbx , 0 
    ret

    mov   rax , 1     ; 1=fail
    mov   rbx , 0
    ret


card_get_all:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Return all supported graphics modes
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    ; In: rcx - entry num (0+)
    
    ; Out:
    mov   rax , 0 ; 0/1 - present/not found
    mov   rbx , 0 ; parameter format
    mov   rcx , x_resolution
    mov   rdx , y_resolution
    mov   r8  , frequency (in 0.01 hz's)
    mov   r9  , lfb_start
    mov   r10 , scanline_in_bytes
    mov   r11 , bytes_per_pixel (3/4)

    ret
   
   
   
card_set_mode:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Set graphics mode
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    ; In:
    mov   rbx , 0 ; parameter format
    mov   rcx , x_resolution
    mov   rdx , y_resolution
    mov   r8  , frequency (in 0.01 hz's)
    mov   r9  , lfb_start
    mov   r10 , scanline_in_bytes
    mov   r11 , bytes_per_pixel (3/4)

    ; Out:
    mov   rax , 0 ; 0/1 - success/fail
    mov   rbx , 0 ; parameter format
    mov   rcx , x_resolution
    mov   rdx , y_resolution
    mov   r8  , frequency (in 0.01 hz's)
    mov   r9  , lfb_start
    mov   r10 , scanline in bytes
    mov   r11 , bytes_per_pixel (3/4)

    ret
   
   
   
card_get_mode:
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;   Get current graphics mode
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

    ; Out:
    mov   rax , 0 ; 0/1 - success/fail
    mov   rbx , 0 ; parameter format
    ; Set following values to zero if card has not initialized
    ; a graphics mode. Value zero equals to undefined.
    mov   rcx , x_resolution
    mov   rdx , y_resolution
    mov   r8  , frequency (in 0.01 hz's)
    mov   r9  , lfb_start
    mov   r10 , scanline_in_bytes
    mov   r11 , bytes_per_pixel (3/4)

    ret

;
; Driver data 
;

parameter1: dq 0x0
parameter2: dq 0x0

;
; Non-cacheable data between driver and device
;

org (driver_base+0x100000*2)

structure1: ; ..
structure2: ; ..


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