On Wed, 5 Feb 2025 at 21:25, Tom Rini <[email protected]> wrote: > > On Wed, Feb 05, 2025 at 09:18:50PM +0200, Ilias Apalodimas wrote: > > Hi Tom, > > > > On Wed, 5 Feb 2025 at 19:33, Tom Rini <[email protected]> wrote: > > > > > > On Wed, Feb 05, 2025 at 09:16:47AM +0200, Ilias Apalodimas wrote: > > > > > > > Upcoming patches are switching the memory mappings to RW, RO, RX > > > > after the U-Boot binary and its data are relocated. Add > > > > annotations in the linker scripts to and mark text, data, rodata > > > > sections and align them to a page boundary. > > > > > > > > It's worth noting that efi_runtime relocations are left untouched for > > > > now. The efi runtime regions can be relocated by the OS when the latter > > > > is calling SetVirtualAddressMap. Which means we have to configure the > > > > pages as RX for U-Boot but convert them to RWX just before > > > > ExitBootServices. It also needs extra code in efi_tuntime relocation > > > > code since R_AARCH64_NONE are emitted as well if we page align the > > > > section. Keep it out for now and we can fix it in future patches. > > > > > > > > Acked-by: Jerome Forissier <[email protected]> > > > > Signed-off-by: Ilias Apalodimas <[email protected]> > > > > --- > > > > arch/arm/cpu/armv8/u-boot.lds | 29 +++++++++++++++++------------ > > > > include/asm-generic/sections.h | 2 ++ > > > > 2 files changed, 19 insertions(+), 12 deletions(-) > > > > > > > > diff --git a/arch/arm/cpu/armv8/u-boot.lds > > > > b/arch/arm/cpu/armv8/u-boot.lds > > > > index 857f44412e07..35afc3cbe7ec 100644 > > > > --- a/arch/arm/cpu/armv8/u-boot.lds > > > > +++ b/arch/arm/cpu/armv8/u-boot.lds > > > > @@ -22,7 +22,7 @@ SECTIONS > > > > > > > > . = ALIGN(8); > > > > __image_copy_start = ADDR(.text); > > > > - .text : > > > > + .text ALIGN(4096): > > > > { > > > > CPUDIR/start.o (.text*) > > > > } > > > > > > Shouldn't this be: > > > - . = ALIGN(8); > > > - __image_copy_start = ADDR(.text); > > > - .text : > > > + .text ALIGN(4096): > > > { > > > + __image_copy_start = ADDR(.text); // Or even just '= .;' ? > > > CPUDIR/start.o (.text*) > > > > IIRC this will produce the exact same output. > > OK, so we don't end up with 8192 worth of alignment here.
We do, but that's because I added an ALIGN(4096) in .text. The change above won't change that. But looking at it again, I don't have to do that now. I can remove the alignment from .text since some efi_runtime services are between that and .text_start. Since my current patch ignores efi_runtime, I can skip the .text alignment, save ~4k and fix the rest when I deal with EFI. > > > Given Richards's idea, I'll move the sections around a bit and define > > rw_start_end, ro_start/end and rx_start/end symbols. > > It would make other architectures life easier if they ever want to > > replicate this. So with those new symbols, adding ifdefs around the > > alignment should be more readable. > > Yes, re-organizing things will help too, I agree. > [...] Regards /Ilias
