Fix STM32H7 DFU mode entry via CLI command

[sensei-hacker]

User description

Summary

Fixes the CLI dfu command on STM32H743/H750 targets. Previously, the command would reboot the board but it would return as a VCP device instead of entering DFU mode for firmware flashing.

Root cause: The bootloader request check was happening too late in the boot sequence (after clock and peripheral initialization). The H7 ROM bootloader requires the RTC backup register check to occur before any system configuration happens.

Solution: moved checkForBootLoaderRequest from src/main/drivers/system_stm32h7xx.c to src/main/target/system_stm32h7xx.c (CMSIS startup, before any hardware initialization). Also enable SYSCFG clock before jumping to bootloader.

Changes

• src/main/target/system_stm32h7xx.c: Added early bootloader check in SystemInit() before any clock configuration
• src/main/drivers/system_stm32h7xx.c: Removed late bootloader check from systemInit()
• src/main/drivers/system.c: Added H7-specific bootloader jump code with SYSCFG clock enablement (properly gated with #if defined(STM32H7))

Platform Impact

H7-specific only. All changes are either in H7-specific files or properly gated with #if defined(STM32H7) in shared files. F4/F7/AT32 platforms are completely unaffected.

Testing

• Target: DAKEFPVH743PRO
• Test: CLI dfu command
• Result: ✅ Successfully enters DFU mode (tested with dfu-util)
• Versions affected: This issue existed in 7.1.2, 8.0.0, and 9.0.0 (not a regression, never worked on H7)

Test Plan

• Tested on H743 hardware - DFU entry works
• Verified F4/F7/AT32 code paths unchanged
• Confirmed all changes are H7-specific or properly gated
• Built and tested firmware successfully

---

PR Type

Bug fix

---

Description

• Move bootloader check to early SystemInit() before clock configuration

• Enable SYSCFG clock before jumping to H7 bootloader

• Add H7-specific bootloader jump code with proper gating

• Remove late bootloader check from systemInit() driver function

---

Diagram Walkthrough

flowchart LR
  A["Boot sequence"] --> B["SystemInit CMSIS startup"]
  B --> C["checkForBootLoaderRequest early"]
  C --> D{"Bootloader request?"}
  D -->|Yes H7| E["Enable SYSCFG clock"]
  E --> F["Jump to bootloader"]
  D -->|No| G["Continue normal boot"]
  D -->|Yes F4/F7| H["Jump to bootloader"]

Loading

File Walkthrough

Relevant files

Bug fix

system.c Add H7-specific bootloader jump with SYSCFG clock                src/main/drivers/system.c Added H7-specific bootloader jump code with __HAL_RCC_SYSCFG_CLK_ENABLE() call Wrapped H7 bootloader logic with #if defined(STM32H7) preprocessor guard Maintained F4/F7 bootloader jump code in else branch Added comments clarifying reset reason clearing and bootloader jump steps +16/-0    system_stm32h7xx.c Remove late bootloader check from systemInit                          src/main/drivers/system_stm32h7xx.c Removed checkForBootLoaderRequest() call from systemInit() function This call is now performed earlier in SystemInit() before clock configuration +0/-2      system_stm32h7xx.c Add early bootloader check in SystemInit                                  src/main/target/system_stm32h7xx.c Added early checkForBootLoaderRequest() call in SystemInit() CMSIS startup function Positioned before FPU configuration and any clock/peripheral initialization Added comment explaining the early check requirement for H7 ROM bootloader +3/-0

---

[qodo-code-review]

ⓘ Your approaching your monthly quota for Qodo. Upgrade your plan

PR Compliance Guide 🔍

All compliance sections have been disabled in the configurations.

[sensei-hacker]

Tested by Daijubou