Figure 21. Secure Image Secondary Slot Region Mapping; Figure 22. Secure Image Format - ST STM32CubeL5 User Manual

Non secure area
Secure area
Reset
entry
point
To use the secure Image secondary slot, data shall be written at the correct format in the Secure image
secondary slot area as illustrated hereafter:
Parameters:
Candidate image written in the "Secure image secondary" slot.
Actions:
At each product reset TOE (TFM_SBSFU application) checks if a new secure image has been pre-loaded by the
non- secure application in the "Secure image secondary" slot. The new secure image shall be programmed at the
beginning of the "Secure image secondary" slot and shall comply with the image format (image header + image
data) as defined by TFM_SBSFU application. When compiling TFM_Appli secure project delivered in
STM32Cube_FW_L5_V1.1.0 SW package (\Projects\STM32L562E-DK\Applications\TFM\TFM_Appli
\STM32CubeIDE\ Project_s.uvprojx) the TFM_Appli secure sign binary with the right format is automatically
generated (TFM_Appli\Binary\tfm_s_sign.bin). When a new secure image is detected, TFM_SBSFU application
will launch the update procedure of the secure Image (that verifies the data before updating the firmware).
UM2745 - Rev 1
Figure 21. Secure image secondary slot region mapping
Non-secure image secondary slot
Non secure area
Area 3
(72 KB)
Non-secure image secondary slot
Non secure area
Area 2
(144 KB)
Non-secure image secondary slot
Non secure
Area 1
application
(72 KB)
Non-secure image secondary slot
Area 0
application
(144 KB)
Secure area
SST area (8KB)
Secure area
ITS area (8KB)
Secure area
NV COUNTER (4 KB)
Secure area
SCRATCH area (8 KB)
Secure area
BL2 NVCNT (4 KB)
TFM_SBSFU
TFM_SBSFU
(46 KB)
Secure area
IntegratorPerso data Area (2KB)
Figure 22.
FLASH_AREA_3_OFFSET: 0x0C06E000
FLASH_AREA_2_OFFSET: 0x0C04A000
FLASH_AREA_1_OFFSET: 0x0C038000
Secure
FLASH_AREA_0_OFFSET: 0x0C014000
FLASH_SST_AREA_OFFSET: 0x0C012000
FLASH_ITS_AREA_OFFSET: 0x0C010000
FLASH_NV_COUNTERS_AREA_OFFSET: 0x0C00F000
FLASH_SWAP_AREA_OFFSET: 0x0C00D000
FLASH_BL2_NVCNT_AREA_OFFSET: 0x0C00C000
FLASH_AREA_BL2_OFFSET: 0x0C000800
FLASH_AREA_PERSO_OFFSET: 0x0C000000
Secure image format
Operational guidance for the role integrator
UM2745
page 25/36