Hi Stefan, On 15 June 2018 at 00:44, Stefan Johansson <[email protected]> wrote: > > Hello, > We have been looking at protecting U-Boot from (malicious) TFTP overwrites. > We want to do this after our ARMv7 U-Boot has relocated. > > The memory map looks like this (I hope): > > --------------------------- Top of DRAM > | U-Boot (Protected) > | -------------------------- U_Boot_start > | Heap (Protected) > | -------------------------- Start_Heap = U_Boot_start - Heap_Size > | Stack (Protected) > | -------------------------- Start_Stack = Start_Heap - Stack_Size > | Buffers (Protected) > | -------------------------- ??? > | Free DRAM (Not Protected) > --------------------------- Start of DRAM > > I seem to get lost in the code trying to find possible buffers, can you > please give a hint how I can find the address "???"
Well gd->start_addr_sp is the stop of the stack. The size of the stack is not necessarily fixed and will grow downwards from there. But I suppose you could set a particular size and protect from start of DRAM to to the assumed bottom of the stack area. Regards, Simon _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
