How the secondary bootloader (SBL) works

[Go4IT]

This thread is to research how the SBL works. It is used for updating the Convers+ and will get downloaded from a VBF file using UDS into the RAM of the MAC7116 and get's called afterwards.
It then takes over control of the whole Convers+ plattform. It's main purpose the is to communicate with the updater, erase the Flash und program the downloaded new one into it.

... to be continued ...

[DGAlexandru]

IPC with PBL and FW from a FaceLift version.
SBL sent with IPC Updater when selecting "EEPROM Edit", and as soon as it starts to download EEPROM contents I put CPU (MAC7116) into Halt mode and then downloaded its RAM content.

As you can see in the 2 attached dump files, the SBL is loaded in RAM at address 0x0FF8.

For disassembling the code I've used the entire (RAM) file.

[Go4IT]

As you can see in the 2 attached dump files, the SBL is loaded in RAM at address 0x0FF8

This must be an offset, because the 48kb RAM starts at 0x4000 0000 up to 0x4000 BFFF.

[DGAlexandru]

OK mr. 0x40 000 FF8 in RAM

0x0FF8 is the offset in the file I have uploaded, file that represents the entire RAM.