On Jan 25, 2008 5:50 PM, Ingo Molnar <[EMAIL PROTECTED]> wrote: > > * Huang, Ying <[EMAIL PROTECTED]> wrote: > > > On Fri, 2008-01-25 at 10:31 +0100, Ingo Molnar wrote: > > > * Huang, Ying <[EMAIL PROTECTED]> wrote: > > > > > > > This patch fixes some bugs of EFI memory handing code. > > > > > > > > - On x86_64, it is possible that EFI memory map can not be mapped via > > > > identity map, so efi_map_memmap is removed, just use early_ioremap. > > > > > > > > - On i386, the EFI memory map mapping take effect cross paging_init, > > > > so it is not necessary to use efi_map_memmap. > > > > > > > > - EFI memory map is unmapped in efi_enter_virtual_mode to avoid > > > > early_ioremap leak. > > > > > > thanks, applied. > > > > > > btw., it would be nice to consolidate this some more. Why is there a > > > separate efi_ioremap(), which is mapped to ioremap() on 32-bit, and > > > which is mapped to a fixmap based special mapper on 64-bit? > > > > > > To me it appears this wants to be ioremap() on both 64-bit and > > > 32-bit, and we could remove efi_ioremap() altogether. Hm? > > > > To support kexec, I want to map the EFI memory area on same virtual > > address on different boot of different version of kernel. Then, the > > EFI runtime service will always get the same execution environment. > > This is because a weakness of EFI runtime service, it can not reset > > its execution environment, except reboot. > > so this basically means that on 32-bit kexec wont work right - i.e. only > 64-bit has been enhanced this way? What am i missing?
Strictly, I should say on 32-bit, EFI runtime service won't work in kexeced kernel. That is, on EFI 32 platform, it is possible that: - Boot kernel A with EFI runtime service - kexec kernel B without EFI runtime service (such as with noefi in kernel command line) I suspect this method can be used on 32-bit platform. Because the fixmap area on 32-bit is more limited than 64-bit. And because identity map area on 32-bit is too limited, it is possible that all EFI runtime code, data, IO areas need to be mapped via fixmap. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
