Physical host disks

Copperline can give the emulated machine a real disk of the host’s -- a CompactFlash or SD card in a reader, a USB flash drive, or a hard drive -- instead of an image. The Amiga uses the medium as it is, with its own Rigid Disk Block (RDB), partitions, and filesystems.

Listing host disks¶

To list the disks the host can see:

copperline --list-disks

Example output:

Host disks (name one to --host-disk, or as [[host_disk]] device):
  sdb        Generic MassStorageClass (31.9 GB)
  sdc        ATA Samsung SSD 870 (500.1 GB) [internal]
  sda        ATA Ubuntu Linux-0 S (68.7 GB) [system disk, internal, mounted: /]  -- cannot be used

Listing opens no device and needs no privileges. Disks on an internal bus are labelled internal but still offered.

Safety protections:

• System disk protection: The disk the host is running from is detected and can never be opened (cannot be used); the launcher does not offer it.

• Raw medium access: The physical medium is presented to the guest as-is. Copperline does not synthesize an RDB for a disk that has none.

Attaching a disk¶

In the launcher¶

1. Go to Storage -> Host Disk.

2. Tick the disk’s Enable box and click its Attach cell to choose the attachment point. R/W is ticked by default; untick it to keep the guest from writing to the disk.

3. Press Mount, and approve the operating system’s permission prompt if one appears.

From the command line¶

--host-disk DEVICE [ATTACH] attaches a disk read-write for this run, and --host-disk-read-only DEVICE [ATTACH] attaches it write-protected. ATTACH defaults to ide-master.

# Read-only mount (recommended for a first test):
copperline --model A1200 --fast 8M KICK31.ROM --host-disk-read-only sdb

# Read-write mount:
copperline --model A1200 --fast 8M KICK31.ROM --host-disk sdb

In copperline.toml¶

[[host_disk]]
device = "sdb"                 # the name --list-disks prints
fingerprint = "v1-..."         # opaque identity written by the launcher
attach = "ide-master"          # attachment point (see table below)
read_only = true               # the default; false allows guest writes

The [[host_disk]] section of the configuration reference gives the full rules.

Attachment options¶

A CompactFlash card from a real Amiga¶

A CF card that lives in an A600’s or A1200’s PCMCIA slot carries the partitions the Amiga’s own CF driver wrote (compactflash.device, cfd.device, or a patched scsi.device), and those drivers expect the card in the slot, not on the IDE cable. Put the reader’s device on the slot and the same driver in the guest finds the same card:

copperline --model A1200 KICK31.ROM --host-disk-read-only disk4 pcmcia

[machine]
profile = "A1200"

[[host_disk]]
device = "disk4"
attach = "pcmcia"
read_only = true

The card is presented through Gayle’s slot windows with the CF register layout a real card has (memory-mapped, contiguous I/O, or PC-style I/O, whichever the driver configures), so the guest sees a card, not an IDE drive; Kickstart’s card.resource reports the insertion but does not mount it by itself. The slot holds one card, so attach = "pcmcia" cannot be combined with a [pcmcia] image, and more than 4M of Zorro II fast RAM disables the slot (see [pcmcia]). A card reader is removable media, so read-write access must be selected afresh each session, as for any other removable disk below.

Device fingerprints and renaming¶

Operating systems may change device names (such as /dev/sdb or disk4) when devices are connected in a different order. To avoid mounting the wrong disk, the launcher saves a fingerprint derived from the drive’s serial number, model, capacity, and sector size.

When a fingerprint is present in the configuration, Copperline matches the device against current host drives. If the match is ambiguous or the device cannot be found, the drive slot stays empty rather than mounting the wrong device, and the machine starts anyway.

Read-write access to removable media (such as a card reader, which often reports its own serial number rather than the card’s) is not kept across restarts, and neither is read-write access to a fixed disk without a credible serial number: select and mount the disk in the launcher before each writing session.

Host operating system permissions¶

Reading or writing a whole disk is privileged on every supported host. The system’s own prompt asks for permission, and what comes back is an open handle to that one device, not general elevated rights:

• Linux: A user in the disk group (or root, or one covered by a site udev rule) opens the device directly. Otherwise Copperline asks through Polkit (pkexec), which usually costs an administrator password.

• macOS: Authorization is requested through the system’s authopen prompt.

• Windows: Copperline runs itself once more with administrator rights, which raises the UAC consent dialog, opens the disk there, and hands the handle back to the running session.

On Linux and Windows, several disks attached together share one prompt.

Safe usage recommendations¶

1. Test with read-only first: Boot the disk with read_only = true (or --host-disk-read-only) to check that its filesystems mount correctly.

2. Host volumes: Copperline unmounts the host’s volumes on the disk while the machine has it; macOS and Linux mount them again when the machine releases the disk. If a volume is busy and cannot be unmounted, the disk is not attached; close whatever is using it and try again. Linux unmounts through udisksctl; on a system without udisks2, unmount the volumes by hand first.

3. Flushing writes: Each IDE or SCSI write command is flushed to the medium before the guest sees it complete, so a finished write is on the disk. A USB bridge with no flush command is noted once in the log.