RP2040 emulated EEPROM. (#17519)

1 files changed, 16 insertions, 1 deletions

diff --git a/docs/eeprom_driver.md b/docs/eeprom_driver.md
index de2eaf2e5b..50d8bcb7b3 100644
--- a/docs/eeprom_driver.md
+++ b/docs/eeprom_driver.md
@@ -92,6 +92,7 @@ Driver                                  | Description
 ----------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 `WEAR_LEVELING_DRIVER = embedded_flash` | This driver is used for emulating EEPROM by writing to embedded flash on the MCU.
 `WEAR_LEVELING_DRIVER = spi_flash`      | This driver is used to address external SPI NOR Flash peripherals.
+`WEAR_LEVELING_DRIVER = rp2040_flash`   | This driver is used to write to the same storage the RP2040 executes code from.
 `WEAR_LEVELING_DRIVER = legacy`         | This driver is the "legacy" emulated EEPROM provided in historical revisions of QMK. Currently used for STM32F0xx and STM32F4x1, but slated for deprecation and removal once `embedded_flash` support for those MCU families is complete.
 
 !> All wear-leveling drivers require an amount of RAM equivalent to the selected logical EEPROM size. Increasing the size to 32kB of EEPROM requires 32kB of RAM, which a significant number of MCUs simply do not have.
@@ -128,6 +129,20 @@ Configurable options in your keyboard's `config.h`:
 
 !> There is currently a limit of 64kB for the EEPROM subsystem within QMK, so using a larger flash is not going to be beneficial as the logical size cannot be increased beyond 65536. The backing size may be increased to a larger value, but erase timing may suffer as a result.
 
+## Wear-leveling RP2040 Driver Configuration :id=wear_leveling-rp2040-driver-configuration
+
+This driver performs writes to the same underlying storage that the RP2040 executes its code.
+
+Configurable options in your keyboard's `config.h`:
+
+`config.h` override                       | Default                    | Description
+------------------------------------------|----------------------------|--------------------------------------------------------------------------------------------------------------------------------
+`#define WEAR_LEVELING_RP2040_FLASH_SIZE` | `PICO_FLASH_SIZE_BYTES`    | Number of bytes of flash on the board.
+`#define WEAR_LEVELING_RP2040_FLASH_BASE` | `(flash_size-sector_size)` | The byte-wise location that the backing storage should be located.
+`#define WEAR_LEVELING_LOGICAL_SIZE`      | `4096`                     | Number of bytes "exposed" to the rest of QMK and denotes the size of the usable EEPROM.
+`#define WEAR_LEVELING_BACKING_SIZE`      | `8192`                     | Number of bytes used by the wear-leveling algorithm for its underlying storage, and needs to be a multiple of the logical size as well as the sector size.
+`#define BACKING_STORE_WRITE_SIZE`        | `2`                        | The write width used whenever a write is performed on the external flash peripheral.
+
 ## Wear-leveling Legacy EEPROM Emulation Driver Configuration :id=wear_leveling-legacy-driver-configuration
 
 This driver performs writes to the embedded flash storage embedded in the MCU much like the normal Embedded Flash Driver, and is only for use with STM32F0xx and STM32F4x1 devices. This flash implementation is still currently provided as the EFL driver is currently non-functional for the previously mentioned families.
@@ -142,4 +157,4 @@ STM32F072 | `1024` bytes    | `2048` bytes
 STM32F401 | `1024` bytes    | `16384` bytes
 STM32F411 | `1024` bytes    | `16384` bytes
 
-Under normal circumstances configuration of this driver requires intimate knowledge of the MCU's flash structure -- reconfiguration is at your own risk and will require referring to the code.
\ No newline at end of file
+Under normal circumstances configuration of this driver requires intimate knowledge of the MCU's flash structure -- reconfiguration is at your own risk and will require referring to the code.