ladybird/Kernel/Storage/ATA/ATADiskDevice.h

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/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/Interrupts/IRQHandler.h>
#include <Kernel/Locking/Mutex.h>
#include <Kernel/Storage/ATA/ATADevice.h>
namespace Kernel {
class IDEController;
class ATADiskDevice final : public ATADevice {
friend class IDEController;
friend class DeviceManagement;
public:
static NonnullLockRefPtr<ATADiskDevice> create(ATAController const&, ATADevice::Address, u16 capabilities, u16 logical_sector_size, u64 max_addressable_block);
virtual ~ATADiskDevice() override;
// ^StorageDevice
virtual CommandSet command_set() const override { return CommandSet::ATA; }
private:
Kernel/Storage: Introduce new boot device addressing modes Before of this patch, we supported two methods to address a boot device: 1. Specifying root=/dev/hdXY, where X is a-z letter which corresponds to a boot device, and Y as number from 1 to 16, to indicate the partition number, which can be omitted to instruct the kernel to use a raw device rather than a partition on a raw device. 2. Specifying root=PARTUUID: with a GUID string of a GUID partition. In case of existing storage device with GPT partitions, this is most likely the safest option to ensure booting from persistent storage. While option 2 is more advanced and reliable, the first option has 2 caveats: 1. The string prefix "/dev/hd" doesn't mean anything beside a convention on Linux installations, that was taken into use in Serenity. In Serenity we don't mount DevTmpFS before we mount the boot device on /, so the kernel doesn't really access /dev anyway, so this convention is only a big misleading relic that can easily make the user to assume we access /dev early on boot. 2. This convention although resemble the simple linux convention, is quite limited in specifying a correct boot device across hardware setup changes, so option 2 was recommended to ensure the system is always bootable. With these caveats in mind, this commit tries to fix the problem with adding more addressing options as well as to remove the first option being mentioned above of addressing. To sum it up, there are 4 addressing options: 1. Hardware relative address - Each instance of StorageController is assigned with a index number relative to the type of hardware it handles which makes it possible to address storage devices with a prefix of the commandset ("ata" for ATA, "nvme" for NVMe, "ramdisk" for Plain memory), and then the number for the parent controller relative hardware index, another number LUN target_id, and a third number for LUN disk_id. 2. LUN address - Similar to the previous option, but instead we rely on the parent controller absolute index for the first number. 3. Block device major and minor numbers - by specifying the major and minor numbers, the kernel can simply try to get the corresponding block device and use it as the boot device. 4. GUID string, in the same fashion like before, so the user use the "PARTUUID:" string prefix and add the GUID of the GPT partition. For the new address modes 1 and 2, the user can choose to also specify a partition out of the selected boot device. To do that, the user needs to append the semicolon character and then add the string "partX" where X is to be changed for the partition number. We start counting from 0, and therefore the first partition number is 0 and not 1 in the kernel boot argument.
2022-08-05 17:32:26 +00:00
ATADiskDevice(ATAController const&, Address, u16, u16, u64);
// ^DiskDevice
virtual StringView class_name() const override;
};
}