os-k/boot/loader/io/ata.asm

;=----------------------------------------------------------------------------=;
;                            GNU GPL OS/K                                      ;
;                                                                              ;
;   Desc:   Basic Read Only ATA Long mode Driver                               ;
;                   (x86_64 architecture only)                                 ;
;                                                                              ;
;                                                                              ;
;   Copyright © 2018-2019 The OS/K Team                                        ;
;                                                                              ;
;   This file is part of OS/K.                                                 ;
;                                                                              ;
;   OS/K is free software: you can redistribute it and/or modify               ;
;   it under the terms of the GNU General Public License as published by       ;
;   the Free Software Foundation, either version 3 of the License, or          ;
;   (at your option) any later version.                                        ;
;                                                                              ;
;   OS/K is distributed in the hope that it will be useful,                    ;
;   but WITHOUT ANY WARRANTY; without even the implied warranty of             ;
;   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the              ;
;   GNU General Public License for more details.                               ;
;                                                                              ;
;   You should have received a copy of the GNU General Public License          ;
;   along with OS/K.  If not, see <https://www.gnu.org/licenses/>.             ;
;=----------------------------------------------------------------------------=;

[BITS 64]

;; BPB
%define OEMName           bp+0x03           ; Disk label
%define bytesPerSector    bp+0x0b           ; Bytes per sector
%define sectorsPerCluster bp+0x0d           ; Sectors per cluster
%define reservedSectors   bp+0x0e           ; Reserved sectors
%define fats              bp+0x10           ; Number of fats
%define rootDirEntries    bp+0x11           ; Number of entries in root dir
%define sectors           bp+0x13           ; Logical sectors
%define mediaType         bp+0x15           ; Media descriptor byte
%define fatSectors        bp+0x16           ; Sectors per FAT
%define sectorsPerTrack   bp+0x18           ; Sectors per track
%define heads             bp+0x1a           ; Number of sides/heads
%define hiddenSectors     bp+0x1c           ; Hidden sectors
%define hugeSectors       bp+0x20           ; LBA sectors
%define biosBootdrvNum    bp+0x24           ; Bootdrv number
%define reserved          bp+0x25           ; This is not used
%define bootSignature     bp+0x26           ; Bootdrv signature
%define volumeId          bp+0x27           ; Volume ID
%define volumeLabel       bp+0x2b           ; Volume Label
%define fatTypeLabel      bp+0x36           ; File system type

;; GLOBAL DATA

Bootdrv         db  0
ended           db  "[End of Sector]", 0x0A, 0x0A, 0x0D, 0x0
buffer:         times 513 db "_"

;; TEXT

ata_read:
;-----------------------------------------------------------------------;
; x64/LM ATA Reading function                                           ;
; bl : number of sectors to read  XXX                                   ;
; bh : the first sector to read                                         ;
;-----------------------------------------------------------------------;

;  Technical infos about the ports (Intel Doc):
;
;       Port   Access Mode  Misc
;
;       1f0       r/w       Data register, the bytes of the disk itself
;       1f1       r         Error register that can be handled
;       1f2       r/w       Sector count, how many sectors to read
;       1f3       r/w       Sector number, the actual sector wanted
;       1f4       r/w       Cylinder low, cylinders is 0-1024
;       1f5       r/w       Cylinder high, this makes up the rest of the 1024
;       1f6       r/w       Drive/head
;                              bit 7 = 1
;                              bit 6 = 0
;                              bit 5 = 1
;                              bit 4 = 0  drive 0 select
;                                    = 1  drive 1 select
;                              bit 3-0    head select bits
;       1f7       r         Status register
;                              bit 7 = 1  controller is executing a command
;                              bit 6 = 1  drive is ready
;                              bit 5 = 1  write fault
;                              bit 4 = 1  seek complete
;                              bit 3 = 1  sector buffer requires servicing
;                              bit 2 = 1  disk data read corrected
;                              bit 1 = 1  index - set to 1 each revolution
;                              bit 0 = 1  previous command ended in an error
;       1f7       w         Command register
;                            commands:
;                              50h format track
;                              20h read sectors with retry
;                              21h read sectors without retry
;                              22h read long with retry
;                              23h read long without retry
;                              30h write sectors with retry
;                              31h write sectors without retry
;                              32h write long with retry
;                              33h write long without retry
;
    push rax
    push rbx
    push rcx
    push rdx
    push rdi
    mov dx, 0x1f6                            ; Drive and head port
    mov al, 0x0a0                            ; Drive 0, head 0
    out dx,al

    mov dx, 0x1f2                            ; Sector count port
    mov al, bl                               ; Read bl(s) sector
    out dx, al

    mov dx, 0x1f3                            ; Sector number port
    mov al, bh                                ; Read from sector n°bh
    out dx, al

    mov dx, 0x1f4                            ; Cylinder low port
    mov al, 0                                ; Cylinder 0
    out dx, al

    mov dx, 0x1f5                            ; Cylinder high port
    mov al, 0                                ; The rest of the cylinder 0
    out dx, al

    mov dx, 0x1f7                            ; Command port
    mov al, 0x20                             ; Read with retry.
    out dx, al
still_going:
    in al, dx
    test al, 8                               ; This means the sector buffer requires
                                                ;servicing.
    jz still_going                           ; Don't continue until the sector buffer
                                                ;is ready.

    mov cx, 512/2                            ; One sector /2 because it copies words
    mov rdi, QWORD buffer
    mov dx, 0x1f0                            ; Data port - data comes in and out of here.
    rep insw
    pop rdi
%ifdef DEBUG
    mov bl, 0x0F
    mov esi, buffer
    call dump
    mov bl, 0x0A
    mov esi, ended
    call write
    add qword [NextTRAM], 120                ; Cursor moving : 1120 = 80 * 2 * 7 lignes
%else
    mov bl, 0x0A
    mov esi, Pass
    call write
%endif
    pop rdx
    pop rcx
    pop rbx
    pop rax
    ret