On 29 June 2017 at 17:41, KONRAD Frederic <frederic.kon...@adacore.com> wrote: > On 06/29/2017 05:14 PM, Peter Maydell wrote: >> This is awkward, because in the "we have a ROM but it's not been >> copied into memory yet" case, the only thing we have is the >> rom->addr, which is the address which the user's ROM blob said >> it ought to be loaded in at. If the user didn't actually provide >> a ROM blob that loads at 0 that seems a bit like a user error, >> and I don't think this patch will catch all the cases of that >> sort of mistake. > > > I don't think it's really a user mistake because on the real HW > the alias is configurable.. at least in my case. > > There is a "jumper" setting to mirror either the Flash or the > SRAM, etc. So the binaries isn't located at 0 but at the flash > address 0x8000000 or some such. That's the case with u-boot and > the precompiled examples I found for this stm32fxxxx board. > >> For instance if address 0 is real flash and the >> high address alias is modelled by having the high address be the >> alias, then if the user passes us an ELF file saying "load to >> the high address" then this change won't catch that I think >> (because doing the memory_region_find/get_offset_within_address_space >> will return 0, which has already been tried). You'd need to >> somehow have a way to say "find all the addresses within this >> AS where this MR is mapped" and try them all... > > > This is more likely to be a user error :). Maybe we can load > the ROM before the reset but that seems a lot more invasive..
It's the same thing, though, right? If the user's ELF file says "vector table is at 0x8000000" then we should either (a) say that's a user error, or (b) handle it right, whether we implemented the QEMU model with the flash at 0 and the alias at 0x8000000, or with the flash at 0x8000000 and the alias at 0. > BTW isn't there a trick with the ELF entry somewhere? Or is that > for the Cortex-A? We don't honour the ELF entry point on M profile (arguably a bug) -- armv7m_load_kernel() ignores the entry point returned by load_elf() in the 'entry' variable. thanks -- PMM
