ACPI for computers with SCSI disks
20090104


Introduction
--------------------------------------------------------------------------
SCSI/RAID drivers usually work better with SMP kernel (?)
If SCSI driver doesn't work then pay attention to 
EARLYMEMINIT=TRUE in CONFIG.SYS (try TRUE and FALSE)



Installation of eComStation on PC with SCSI
--------------------------------------------------------------------------

When installing eComStation on PC with SCSI:
* If going to run in SMP APIC mode then disable ACPI.PSD
* else you can activate ACPI.PSD


Setup of ACPI.PSD for PC with SCSI
--------------------------------------------------------------------------

If you have SCSI then try to use /SMP /PIC 
(/SMP /APIC requires extra efforts)


You have choices:
* PIC UNI - no changes since 2001
* SMP PIC -- no changes since 2001
* SMP APIC, REMAP -- try remap IRQs


SMP APIC, use patched (updated) drivers
========================================

Check the list of patched SCSI drivers:
http://ecomstation.ru/projects/acpitools/?action=acpi-smp-drv



SMP APIC, REMAP
================

The purpose of REMAP is to make the old drivers unable to understand 
the high irq levels to work in APIC enviroment remapping the high IRQ 
given by the APIC back to PIC lower irq. 
     
So, if you have the driver that does not work with high irq 
(i.e. well known SYM8XX.ADD or SYM_HI.ADD) do the 
following to make it work in APIC mode:

       1. Boot without /APIC and do copy acpica$ acpi.log
       
       2. Find in acpi.log the pci scan log and the line in it corresponding 
          to your device. It will look like

          4:1.0  1000:21       IRQs: PCI:10 PIC:'LNKA':10 APIC:24 Apic Set: 10 

          There 1000 - vendor id, 21 - device id of your device. You can find 
          the vendor/device ids of your device in pci.exe output. Just 
          search there the name of your device. In this line we see the ordinal 
          PIC irq level is 10, APIC irq level is 24. So we must map 
          back 24 irq to 10

       3. Put the line REMAP 24 10 in \os2\boot\acpi.cfg, put /APIC switch to 
          your ACPI.PSD, reboot.
          You may need more the one such iteration to make all your drivers 
          to work fine in APIC. This stuff is not very convenient to perform, 
          but there are ways planned to ease the remaps for end users in future 
          releases. 
     (thx nickk)