Hi Joel, > From: Joel Stanley <[email protected]> > Sent: Tuesday, June 28, 2022 12:24 PM > > Hi Chai Wei, > > On Wed, 1 Jun 2022 at 08:21, Chia-Wei Wang > <[email protected]> wrote: > > > > The commit b583348ca8c8 ("image: fit: Align hash output buffers") > > places the hash output buffer at the .bss section. However, AST2600 by > > default executes SPL in the NOR flash XIP way. This results in the > > hash output cannot be written to the buffer as it is located at the R/X only > region. > > > > We need to move the .bss section out of the SPL body to the DRAM > > space, where hash output can be written to. This patch includes: > > - Define the .bss section base and size > > - A new SPL linker script is added with a separate .bss region > > specified > > - Enable CONFIG_SPL_SEPARATE_BSS kconfig option > > > > Signed-off-by: Chia-Wei Wang <[email protected]> > > This patch breaks booting for me. > > My concern with the approach is it creates extra maintenance work. > When changes are made to the main linker script they need to be mirrored > here, or else the aspeed port will miss out. (Having the machine tested in CI > will help this somewhat, but only for the code paths we can test under > emulation).
The patch was trying to solve the hash buffer allocation change to common code and to avoid similar issues. But I agree there is additional maintenance work on the customized linker script. > > I know the patch has been merged, but I have a few questions: > > I imagine the ast2600 is not the only board that runs XIP. How do other boards > solve the problem? > > What happens when a symbol that is used before DRAM training has > completed is placed in bss? Honestly, I am not sure how other platforms/boards dealing with this. But like U-Boot REAME stated, the initial global data is read-only. I guess we have to be careful about the global variable use before DRAM initialization or even variable relocation. > > How do you plan to support systems that don't have NOR? We would like to have another defconfig for eMMC booting. If the NOR-based linker script is not applicable, the default one can be used. Chiawei
