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commit 36149b775ef8430ff892d16a00cdc74af841e2e7
Author: Ricardo Maurizio Paul <[email protected]>
AuthorDate: Tue Oct 6 12:07:59 2026 +0200

    Documentation/stm32h5: document the ICACHE and the MPU.
    
    Add an ICACHE section to the STM32H5 platform page.  With
    CONFIG_STM32_ICACHE the OTP, read-only and EDATA flash areas are mapped
    non-cacheable with an MPU region, so they can be read like any other
    memory.
    
    The MPU is not applied in the HardFault and NMI handlers (HFNMIENA=0),
    so these areas must not be read from NMI or HardFault context: with the
    ICACHE enabled such a read raises a bus fault.
    
    Assisted-by: Claude:claude-sonnet-5-5
    Signed-off-by: Ricardo Maurizio Paul <[email protected]>
---
 Documentation/platforms/arm/stm32h5/index.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/platforms/arm/stm32h5/index.rst 
b/Documentation/platforms/arm/stm32h5/index.rst
index 4432d1a0bcf..c60d0d8969b 100644
--- a/Documentation/platforms/arm/stm32h5/index.rst
+++ b/Documentation/platforms/arm/stm32h5/index.rst
@@ -85,6 +85,17 @@ OTP         Yes
 
 ==========  =======  =====
 
+ICACHE
+------
+
+With ``CONFIG_STM32_ICACHE`` the OTP, read-only (UID, flash size, package) and
+EDATA flash areas (0x08fff000-0x09017fff) are mapped non-cacheable with an MPU
+region, so they can be read like any other memory.
+
+The MPU is not applied in the HardFault and NMI handlers (``HFNMIENA=0``), so
+these areas must not be read from NMI or HardFault context: with the ICACHE
+enabled such a read raises a bus fault.
+
 USB FS Host
 -----------
 

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