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OS_ScreenMode 64

OS SWI Calls
» OS_ScreenMode
» OS_ScreenMode 64

OS_ScreenMode 64

(SWI &65)
Entry
R0 64
R1 Flags (reserved, should be zero)
R2 Pointer to GraphicsV Device driver name
Exit
R0 Allocated driver number
All other registers preserved

Use

The purpose of this call is to register a new GraphicsV Device driver with the system. This call should be made before the driver installs itself on the GraphicsV vector, so that the driver knows which driver ID to respond to.

Once the driver has installed itself on GraphicsV and completed its hardware initialisation, it should call OS_ScreenMode 65 to indicate that it is ready for use.

Notes

The driver name pointed to be R2 must be null-terminated and must remain valid for the lifetime of the driver (i.e. until OS_ScreenMode 67 is called). The name is intended to be used by the OS and applications as a unique identifier for the device; the following conventions should be used:

  • The name must not contain spaces or other non-printable characters. This makes it easy to use the driver name on the command line, in system variables, configuration files, etc.
  • In most cases the driver module name is an acceptable driver identifier.
  • If the same driver is able to support multiple devices, use a name of the format ‘<driver>#<id>’ where <driver> is the driver name and <id> is a unique identifier for the device instance
  • Where possible the device id suffix must uniquely identify the same device on the same system across system reboots.
    • For podules, the podule number should be sufficient
    • For PCI devices, the PCI device handle should be sufficient
    • For USB devices, using the usb device number is not recommended as USB devices may be connected/disconnected frequently or the number may be unstable across reboots due to device enumeration order. Instead some combination of the vendor & product ID or device name are recommended.

See also

  • OS_ScreenMode
  • OS_ScreenMode 65
  • OS_ScreenMode 67
  • GraphicsV
Other languages documentation

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Revised on June 24, 2018 12:38:56 by nemo (145) (86.7.33.6)
Edit | Back in time (3 revisions) | See changes | History | Views: Print | Source | Linked from: OS_ScreenMode, GraphicsV, OS_ScreenMode 68, OS_ScreenMode 65, OS_ScreenMode 67, OS_ScreenMode 68 (français), OS_ScreenMode 67 (français), OS_ScreenMode 65 (français), OS_ScreenMode 64 (français)

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