Changeset 143

Timestamp:

Apr 8, 2017, 12:27:39 AM (8 years ago)

Author:

Ben Rietbroek

Message:

Added function to scan all disks for base information [v1.1.1-testing]

This function does the initial scanning of disks with the purpose of
populating the DISKINFO structures for each disk.

It precedes the second scanning stage, which involves scanning disks to
gather info about partitions etc.

CAUTION:
This is a testbuild !
AirBoot uses the BIOS to access disks and a small coding error can trash
partition tables or other vital disk structures. You are advised to make
backups of TRACK0 and EBRs before using this testbuild. More info at:
​https://rousseaux.github.io/netlabs.air-boot/pdf/AirBoot-v1.1.0-manual.pdf

File:

• trunk/bootcode/regular/driveio.asm (modified) (1 diff)

trunk/bootcode/regular/driveio.asm

@@ -1720 +1720 @@
 
 ;------------------------------------------------------------------------------
+; Scan all disks to gather information
+;------------------------------------------------------------------------------
+; IN    : None
+; OUT   : CF=1  - some failure occured
+;       : ZF=1  - no harddisks
+; NOTE  : This does the preliminary gathering of disk information
+;------------------------------------------------------------------------------
+DriveIO_ScanDisks   Proc    Near
+
+IFDEF   AUX_DEBUG
+        IF 1
+        DBG_TEXT_OUT_AUX    'DriveIO_ScanDisks:'
+        PUSHRF
+            call    DEBUG_DumpRegisters
+            ;~ call    AuxIO_DumpParagraph
+            ;~ call    AuxIO_TeletypeNL
+        POPRF
+        ENDIF
+ENDIF
+
+        ; Save all registers
+        pusha
+
+        ; Get number of disks in DH
+        call    DriveIO_GetHardDriveCount
+
+        ; Check if there are any disks to scan
+        xor     cx, cx                      ; Prepare 16-bit counter
+        mov     cl, dh                      ; Number of disks now in CX
+        jcxz    DriveIO_ScanDisks_end       ; Quit if no disks
+
+        ; Scan disks from 80h upward
+        mov     dl, 80h                     ; BIOS number of first disk
+    DriveIO_ScanDisks_next:
+        call    DriveIO_GatherDiskInfo      ; Gather info for this disk
+        jc       DriveIO_ScanDisks_end      ; Quit if some error occured
+        inc     dl                          ; Advance to next disk
+        loop    DriveIO_ScanDisks_next      ; Scan next disk if there is one
+        test    dl, dl                      ; Set ZF=0
+        clc                                 ; Indicate success
+
+    DriveIO_ScanDisks_end:
+        ; Restore all registers
+        popa
+
+        ret
+DriveIO_ScanDisks   EndP
+
+;------------------------------------------------------------------------------
 ; Calculate pointer to entry in DISKINFO structure
 ;------------------------------------------------------------------------------