bb09de6a6d
- Created driver framework with probe/init lifecycle. Drivers register via REGISTER_DRIVER macro which places pointers in a .drivers linker section. - During boot, init_drivers() iterates the section, probes each driver (checking if hardware is present), and initializes those that respond OK. - Added .drivers section to linker.ld with __drivers_start/__drivers_end symbols for iteration. - Also added .rodata.* pattern to the .rodata section for string literals placed in sub-sections by the compiler. - No drivers are registered yet; the VGA driver will be the first. Tested: boots cleanly with driver scan completing (0 registered, 0 loaded).
57 lines
1.8 KiB
C
57 lines
1.8 KiB
C
/**
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* @file driver.h
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* @brief Kernel driver architecture.
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*
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* Provides a simple framework for registering and initializing kernel drivers.
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* Each driver provides a probe function that returns whether it should load,
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* and an init function that performs the actual initialization.
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*
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* Drivers are registered at compile time using the REGISTER_DRIVER macro,
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* which places driver descriptors in a special linker section. The kernel
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* iterates over all registered drivers during boot.
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*/
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#ifndef DRIVER_H
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#define DRIVER_H
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#include <stdint.h>
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/** Driver probe result codes. */
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typedef enum {
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DRIVER_PROBE_OK = 0, /**< Driver should be loaded. */
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DRIVER_PROBE_NOT_FOUND = 1, /**< Hardware not found, skip this driver. */
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DRIVER_PROBE_ERROR = 2 /**< Error during probing. */
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} driver_probe_result_t;
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/**
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* Driver descriptor structure.
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*
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* Each driver provides a name, a probe function (to test if hardware is
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* present), and an init function (to set up the driver).
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*/
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typedef struct driver {
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const char *name; /**< Human-readable driver name. */
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driver_probe_result_t (*probe)(void); /**< Probe function. Returns DRIVER_PROBE_OK if driver should load. */
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int (*init)(void); /**< Init function. Returns 0 on success, non-zero on failure. */
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} driver_t;
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/**
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* Register a driver.
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*
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* Places the driver descriptor in the .drivers linker section so it
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* is automatically discovered during boot.
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*/
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#define REGISTER_DRIVER(drv) \
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static const driver_t * __attribute__((used, section(".drivers"))) \
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_driver_##drv = &(drv)
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/**
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* Initialize all registered drivers.
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*
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* Iterates over the .drivers section, probes each driver, and initializes
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* those that respond positively to probing.
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*/
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void init_drivers(void);
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#endif /* DRIVER_H */
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