-------------------------------------------------- Here is a message for you from http://web2mail.com The easy way to read and send POP email on the web -------------------------------------------------- My employer is using Linux as a boot-loader of sorts which eventually boots another OS. We have some proprietary code which runs in real mode between the time Linux runs and the next operating system is chain-booted (we use kexec return to real mode after Linux). This proprietary code makes use of the BIOS disk calls via int13. In short we need to the BIOS Int13 after Linux. Our system seems to work well on most machines, however it does not work on any machine that make use of AHCI. As soon as we make the first Int13 call after the Linux AHCI driver has been initialized, the machine goes off into the weeds. I been looking though your archives and reading the AHCI spec. It seems clear that the hardware has at least some state contained within it; I'm wondering if there is any hope of putting the chip back to a known state that the BIOS will be able to handle. 1)In reading the AHCI spec, I notice in chapter 10.6 they talk about a bit that when set by the OS driver, control of the AHCI hardware is irrevocably passed to the OS, your driver does not seem to touch that bit so I'm hoping that it is reasonable to pass back control to the BIOS by either resetting the chip or simply placing it into a quiescent state. 2)I also have noticed that you do not do anything special when the AHCI module is removed. That is, you simply use the ata_pci_remove_one() function instead of one particular to the AHCI chip. Could anyone lend some guidance as to what has to be done to put the hardware back into a sane state for BIOS, or if there is a good reason that this is not achievable. Any prior work or manuals that I should ?rtfm? or other wisdom would be greatly appreciated. Thank you. Mike - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html