src/include/boot_device.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #ifndef _BOOT_DEVICE_H_
   4 #define _BOOT_DEVICE_H_
   5
   6 #include <commonlib/region.h>
   7
   8 /*
   9  * Boot device region can be protected by 2 sources, media and controller.
  10  * The following modes are identified. It depends on the flash chip and the
  11  * controller if mode is actually supported.
  12  *
  13  * MEDIA_WP : Flash/Boot device enforces write protect
  14  * CTRLR_WP : Controller device enforces write protect
  15  * CTRLR_RP : Controller device enforces read protect
  16  * CTRLR_RWP : Controller device enforces read-write protect
  17  */
  18 enum bootdev_prot_type {
  19         CTRLR_WP = 1,
  20         CTRLR_RP = 2,
  21         CTRLR_RWP = 3,
  22         MEDIA_WP = 4,
  23 };
  24 /*
  25  * Please note that the read-only boot device may not be coherent with
  26  * the read-write boot device. Thus, mixing mmap() and writeat() is
  27  * most likely not to work so don't rely on such semantics.
  28  */
  29
  30 /* Return the region_device for the read-only boot device. This is the root
  31    device for all CBFS boot devices. */
  32 const struct region_device *boot_device_ro(void);
  33
  34 /* Return the region_device for the read-write boot device. */
  35 const struct region_device *boot_device_rw(void);
  36
  37 /*
  38  * Create a sub-region of the read-only boot device.
  39  * Returns 0 on success, < 0 on error.
  40  */
  41 int boot_device_ro_subregion(const struct region *sub,
  42                                 struct region_device *subrd);
  43
  44 /*
  45  * Create a sub-region of the read-write boot device.
  46  * Returns 0 on success, < 0 on error.
  47  */
  48 int boot_device_rw_subregion(const struct region *sub,
  49                                 struct region_device *subrd);
  50
  51 /*
  52  * Write protect a sub-region of the boot device represented
  53  * by the region device.
  54  * Returns 0 on success, < 0 on error.
  55  */
  56 int boot_device_wp_region(const struct region_device *rd,
  57                                 const enum bootdev_prot_type type);
  58
  59 /*
  60  * Initialize the boot device. This may be called multiple times within
  61  * a stage so boot device implementations should account for this behavior.
  62  **/
  63 void boot_device_init(void);
  64
  65 /*
  66  * Restrict read/write access to the boot-media using platform defined rules.
  67  */
  68 #if CONFIG(BOOTMEDIA_LOCK_NONE) || (CONFIG(BOOTMEDIA_LOCK_IN_VERSTAGE) && ENV_RAMSTAGE)
  69 static inline void boot_device_security_lockdown(void) {}
  70 #else
  71 void boot_device_security_lockdown(void);
  72 #endif
  73 #endif /* _BOOT_DEVICE_H_ */