Messages in this thread | | | Date | Tue, 15 Jan 2019 15:21:21 +0800 | From | Chao Fan <> | Subject | Re: [PATCH v15 3/6] x86/boot: Introduce efi_get_rsdp_addr() to find RSDP from EFI table |
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On Mon, Jan 14, 2019 at 10:07:56AM +0100, Borislav Petkov wrote: >On Mon, Jan 14, 2019 at 09:26:42AM +0800, Chao Fan wrote: >> According to the code, I saw: >> #ifdef ACPI_ASL_COMPILER >> #define ACPI_32BIT_PHYSICAL_ADDRESS >> #endif >> >> and then >> #ifdef ACPI_32BIT_PHYSICAL_ADDRESS >> typedef u32 acpi_physical_address; >> >> As for ACPI_ASL_COMPILER, I saw iASL in documention, but can't find more >> information in the code. If I miss something, please let me know. > >And, as a result, can acpi_physical_address ever be u32 in a kernel >build?
In my understanding after looking into the commit message the comments. I thinks yes. For 32-bit OS: 32-bit OS without PAE, it's u32. 32-bit OS with PAE in 64-bit machine, it's u64.
So I thinks there is some situations where it's u32. 'acpi_physical_address' was always u32 for 32-bit OS, and then to solve some problems, "Zheng, Lv" add the commit. So I have added to Cc "Zheng, Lv" , I am not sure whether "Zheng, Lv" can give some suggestion about when acpi_physical_address is defined as u32.
Thanks, Chao Fan
> >git annotate is also very helpful when doing git archeology like, for >example, finding the patch which added the ifdeffery and looking at its >commit message for more hints. > >-- >Regards/Gruss, > Boris. > >Good mailing practices for 400: avoid top-posting and trim the reply. > >
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