From 200001eb140ea33477965f2050bea0dac801974b Mon Sep 17 00:00:00 2001 From: Paul Jackson Date: Wed, 25 Jun 2008 05:44:46 -0700 Subject: [PATCH] x86 boot: only pick up additional EFI memmap if add_efi_memmap flag Applies on top of the previous patch: x86 boot: add code to add BIOS provided EFI memory entries to kernel Instead of always adding EFI memory map entries (if present) to the memory map after initially finding either E820 BIOS memory map entries and/or kernel command line memmap entries, -instead- only add such additional EFI memory map entries if the kernel boot option: add_efi_memmap is specified. Requiring this 'add_efi_memmap' option is backward compatible with kernels that didn't load such additional EFI memory map entries in the first place, and it doesn't override a configuration that tries to replace all E820 or EFI BIOS memory map entries with ones given entirely on the kernel command line. Signed-off-by: Paul Jackson Cc: "Yinghai Lu" Cc: "Jack Steiner" Cc: "Mike Travis" Cc: "Huang Cc: Ying" Cc: "Andi Kleen" Cc: "Andrew Morton" Cc: Paul Jackson Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 3 +++ Documentation/x86/x86_64/uefi.txt | 4 ++++ arch/x86/kernel/efi.c | 16 ++++++++++++++-- 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index da13d6d1b2b0..795c487af8e4 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2150,6 +2150,9 @@ and is between 256 and 4096 characters. It is defined in the file usbhid.mousepoll= [USBHID] The interval which mice are to be polled at. + add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in + kernel's map of available physical RAM. + vdso= [X86-32,SH,x86-64] vdso=2: enable compat VDSO (default with COMPAT_VDSO) vdso=1: enable VDSO (default) diff --git a/Documentation/x86/x86_64/uefi.txt b/Documentation/x86/x86_64/uefi.txt index 7d77120a5184..a5e2b4fdb170 100644 --- a/Documentation/x86/x86_64/uefi.txt +++ b/Documentation/x86/x86_64/uefi.txt @@ -36,3 +36,7 @@ Mechanics: services. noefi turn off all EFI runtime services reboot_type=k turn off EFI reboot runtime service +- If the EFI memory map has additional entries not in the E820 map, + you can include those entries in the kernels memory map of available + physical RAM by using the following kernel command line parameter. + add_efi_memmap include EFI memory map of available physical RAM diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c index a03ca36a302c..94382faeadb6 100644 --- a/arch/x86/kernel/efi.c +++ b/arch/x86/kernel/efi.c @@ -64,6 +64,17 @@ static int __init setup_noefi(char *arg) } early_param("noefi", setup_noefi); +int add_efi_memmap; +EXPORT_SYMBOL(add_efi_memmap); + +static int __init setup_add_efi_memmap(char *arg) +{ + add_efi_memmap = 1; + return 0; +} +early_param("add_efi_memmap", setup_add_efi_memmap); + + static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) { return efi_call_virt2(get_time, tm, tc); @@ -219,7 +230,7 @@ unsigned long efi_get_time(void) * (zeropage) memory map. */ -static void __init add_efi_memmap(void) +static void __init do_add_efi_memmap(void) { void *p; @@ -406,7 +417,8 @@ void __init efi_init(void) if (memmap.desc_size != sizeof(efi_memory_desc_t)) printk(KERN_WARNING "Kernel-defined memdesc" "doesn't match the one from EFI!\n"); - add_efi_memmap(); + if (add_efi_memmap) + do_add_efi_memmap(); /* Setup for EFI runtime service */ reboot_type = BOOT_EFI; -- 2.20.1