3.4 KiB
Executable File
FVP Base platform overview
Boot sequence
FVP Base emulator is typically launched using both a secure flashloader and a normal flashloader. The configuration looks like this:
-C bp.secureflashloader.fname=path/to/arm-trusted-firmware/build/fvp/debug/bl1.bin \
-C bp.flashloader0.fname=path/to/fip.bin
We use Arm Trusted Firmware (ATF) as the secure monitor running at S-EL3. It initializes the system, sets up the secure world, and pass control to the non-secure world.
The boot sequence works in the following way:
-
BL1 (Secure ROM Bootloader) - Initializes trusted components and loads the next stage (BL2).
-
BL2 (Trusted Boot Firmware) - Verifies and loads the next stages: BL31 and BL33.
-
BL31 (EL3 Runtime Firmware) - Provides runtime services at EL3, including PSCI (Power State Coordination Interface) and context switching between secure and non-secure worlds.
-
BL32 (Secure Payload) - optional secure-world component that runs at S-EL1. It is used to provide Trusted Execution Environment (TEE). If not required, this stage can be skipped, and BL31 will directly pass control to BL33. In our case we do not use BL32.
-
BL33 (Non-secure Payload) - The final stage of the boot chain, typically the entry point to the non-secure kernel or bootloader. We use little kernel as BL33.
Memory Usage (bytes) [RAM]
| Component | Start | Limit | Size | Free | Total |
|---|---|---|---|---|---|
| BL1 | 0x4034000 | 0x4040000 | 0x7000 | 0x5000 | 0xc000 |
| BL2 | 0x4020000 | 0x4034000 | 0x10000 | 0x4000 | 0x14000 |
| BL2U | 0x4020000 | 0x4034000 | 0xa000 | 0xa000 | 0x14000 |
| BL31 | 0x4003000 | 0x4040000 | 0x22000 | 0x1b000 | 0x3d000 |
Memory Usage (bytes) [ROM]
| Component | Start | Limit | Size | Free | Total |
|---|---|---|---|---|---|
| BL1 | 0x0000000 | 0x4000000 | 0x8bd0 | 0x3ff7430 | 0x4000000 |
To check the memory layout, refer to TF-A Memory Layout Tool Documentation
Little kernel and DTB location
On the FVP platform, DTB start address and the BL33 entry point are both configured in the platform’s source files:
- DTB base address:
0x82000000 (32MB size) - BL33 entry address:
0x88000000
You can find these settings in the platform_def.h header file:
DTS for FVP Base you can find at fdts
Peripheral Address Map
The peripheral address map for the FVP Base platform can be found in the following documentation:
Base Platform memory map
Currently, little kernel supports:
- UART0,PL011
- GICv2
Interrupt Assignment
The interrupt assignment for the FVP Base platform can be found in the following documentation:
Base Platform interrupt assignments