45 lines
1.8 KiB
Markdown
45 lines
1.8 KiB
Markdown
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# STM32 dual-bank flash Bootloader
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## Overview
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This bootloader leverages `embassy-boot` to interact with the flash.
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This example targets STM32 devices with dual-bank flash memory, with a primary focus on the STM32H747XI series.
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Users must modify the `memory.x` configuration file to match with the memory layout of their specific STM32 device.
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Additionally, this example can be extended to utilize external flash memory, such as QSPI, for storing partitions.
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## Memory Configuration
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In this example's `memory.x` file, various symbols are defined to assist in effective memory management within the bootloader environment.
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For dual-bank STM32 devices, it's crucial to assign these symbols correctly to their respective memory banks.
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### Symbol Definitions
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The bootloader's state and active symbols are anchored to the flash origin of **bank 1**:
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- `__bootloader_state_start` and `__bootloader_state_end`
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- `__bootloader_active_start` and `__bootloader_active_end`
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In contrast, the Device Firmware Upgrade (DFU) symbols are aligned with the DFU flash origin in **bank 2**:
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- `__bootloader_dfu_start` and `__bootloader_dfu_end`
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```rust
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__bootloader_state_start = ORIGIN(BOOTLOADER_STATE) - ORIGIN(**FLASH**);
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__bootloader_state_end = ORIGIN(BOOTLOADER_STATE) + LENGTH(BOOTLOADER_STATE) - ORIGIN(**FLASH**);
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__bootloader_active_start = ORIGIN(ACTIVE) - ORIGIN(**FLASH**);
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__bootloader_active_end = ORIGIN(ACTIVE) + LENGTH(ACTIVE) - ORIGIN(**FLASH**);
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__bootloader_dfu_start = ORIGIN(DFU) - ORIGIN(**DFU**);
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__bootloader_dfu_end = ORIGIN(DFU) + LENGTH(DFU) - ORIGIN(**DFU**);
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```
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## Flashing the Bootloader
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To flash the bootloader onto your STM32H747XI device, use the following command:
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```bash
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cargo flash --features embassy-stm32/stm32h747xi-cm7 --release --chip STM32H747XIHx
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```
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