x86 boot: add code to add BIOS provided EFI memory entries to kernel (69c91893) · Commits · 戴 / test

Add to the kernels boot memory map 'memmap' entries found in the EFI memory descriptors passed in from the BIOS. On EFI systems, up to E820MAX == 128 memory map entries can be passed via the legacy E820 interface (limited by the size of the 'zeropage'). These entries can be duplicated in the EFI descriptors also passed from the BIOS, and possibly more entries passed by the EFI interface, which does not have the E820MAX limit on number of memory map entries. This code doesn't worry about the likely duplicate, overlapping or (unlikely) conflicting entries between the EFI map and the E820 map. It just dumps all the EFI entries into the memmap[] array (which already has the E820 entries) and lets the existing routine sanitize_e820_map() sort the mess out. Signed-off-by:

Paul Jackson <pj@sgi.com> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/efi.c

+26 −0

Original line number	Diff line number	Diff line
		@@ -213,6 +213,31 @@ unsigned long efi_get_time(void)
		eft.minute, eft.second);
		}

		/*
		* Tell the kernel about the EFI memory map. This might include
		* more than the max 128 entries that can fit in the e820 legacy
		* (zeropage) memory map.
		*/

		static void __init add_efi_memmap(void)
		{
		void *p;

		for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		efi_memory_desc_t *md = p;
		unsigned long long start = md->phys_addr;
		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
		int e820_type;

		if (md->attribute & EFI_MEMORY_WB)
		e820_type = E820_RAM;
		else
		e820_type = E820_RESERVED;
		add_memory_region(start, size, e820_type);
		}
		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
		}

		#if EFI_DEBUG
		static void __init print_efi_memmap(void)
		{
		@@ -370,6 +395,7 @@ 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();

		/* Setup for EFI runtime service */
		reboot_type = BOOT_EFI;

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