h6. [[GraphicsV]] h6(. » GraphicsV 16 h2. Graphics Vector (42) |_<^{width:3em}. Entry |<^. | |<^. R0|<^. Suggested mode number or [[Mode Selector Block]] | |/3<^. R4|<^. Bits 0-15: 16 (reason code)| |<^. Bits 16-23: Head number| |<^. Bits 24-31: Driver number| |_<^{width:3em}. Exit |<^. | |<^. R0|<^. Mode number/selector to use| |<^. R4|<^. 0| |- |<^. All other registers preserved | h4. Use This call allows a GraphicsV driver to override the choice of screen mode in certain situations, e.g. on driver startup, or the default mode used by the Wimp. For example, a device with a fixed size LCD may want to select a mode which fills the display. h4. Notes The kernel issues this call from within [[OS_ReadSysInfo 1]]. However, it will only issue it under certain circumstances - see the OS_ReadSysInfo page for details. If the mode returned refers to a mode definition which is not one of the kernel's numbered modes, a suitable mode definition needs to have been loaded, e.g. from a ResourceFS based built in [[MDF]]. Service_ModeExtension can then subsequently find it and provide the relevant settings. If there is not a mode definition file, a custom [[Service_ModeExtension]] response needs to be provided. h4. See also * [[GraphicsV]]