101 lines
3.0 KiB
C
101 lines
3.0 KiB
C
#ifndef __VHEX_DRIVER__
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# define __VHEX_DRIVER__
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#include <vhex/defs/types.h>
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/* Device drivers */
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struct vhex_driver
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{
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/* Driver name */
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char const *name;
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// "Hypervisor" calls
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/* Determine whether the device is powered. If NULL, the device is
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assumed to be permanently powered. */
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bool (*hpowered)(void);
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/* Power on the device; this should allow register access to save the
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peripheral state, with minimal state changes. Cannot be NULL if
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hpowered() can return false. */
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void (*hpoweron)(void);
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/* Power off the device; Cannot be NULL if hpowered() can return
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false. */
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void (*hpoweroff)(void);
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/* Save the hardware state; the (state) pointer points to a 4-aligned
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region of (state_size) bytes. */
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void (*hsave)(void *state);
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/* Restore a hardware state previously saved by hsave(). */
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void (*hrestore)(void const *state);
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// Standard calls
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/* Initialize the hardware for the driver to work in vhex. Usually
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installs interrupt handlers and configures registers. May be NULL. */
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void (*configure)(void *state);
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// Internal information
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/* Size of the peripheral's hardware state (assumed 4-aligned) */
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uint16_t state_size;
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/* default flags for the driver */
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int default_flag;
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};
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enum {
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/* Driver is used by default (will be configured) */
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VHEX_DRV_USED = 0x00,
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/* Driver is not used by the world */
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VHEX_DRV_UNUSED = 0x01,
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/* Driver does not require hardware state saves during world switches */
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VHEX_DRV_SHARED = 0x02,
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};
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/* VHEX_DECLARE_DRIVER(): Declare a driver to the kernel
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Use this macro to declare a driver by passing it the name of a
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vhex_world_core structure. This macro moves the structure to the
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.vhex.drivers.* sections, which are automatically traversed at startup.
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The level argument represents the priority level: lower numbers mean that
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drivers will be loaded sooner. This numbering allows a primitive form of
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dependency for drivers. You need to specify a level which is strictly
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higher than the level of all the drivers you depend on.
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The level number *MUST HAVE EXACTLY 2 DIGITS*, as it is used as a string in
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the section name and the linker then sorts by name. If your driver has a
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level lower than 10, you must add a leading 0. */
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#define VHEX_DECLARE_DRIVER(level, name) \
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VSECTION(".vhex.drivers." #level) extern struct vhex_driver name;
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//---
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// Internal driver control
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//
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// The following data is exposed for introspection and debugging purposes; it
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// is not part of the vhex API. There is *no stability guarantee* that the
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// following types and functions will remain unchanged in future minor and
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// patch versions.
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//---
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/* Number of drivers in the (vhex_drivers) array */
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#define vhex_driver_count() \
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((struct vhex_driver *)&vhex_drivers_end \
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- (struct vhex_driver *)&vhex_drivers_start)
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/* driver table */
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#define vhex_driver_table() \
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((struct vhex_driver *)&vhex_drivers_start)
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/* provided by the linker script */
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extern uintptr_t vhex_drivers_start;
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extern uintptr_t vhex_drivers_end;
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#endif /* __VHEX_DRIVER__ */
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