1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
index a25675833598..333ed9c37751 100644
--- a/drivers/firmware/efi/efi-stub-helper.c
+++ b/drivers/firmware/efi/efi-stub-helper.c
@@ -485,3 +485,38 @@ fail:
 
 	return status;
 }
+
+static efi_status_t relocate_kernel(struct setup_header *hdr)
+{
+	unsigned long start, nr_pages;
+	efi_status_t status;
+
+	/*
+	 * The EFI firmware loader could have placed the kernel image
+	 * anywhere in memory, but the kernel has various restrictions
+	 * on the max physical address it can run at. Attempt to move
+	 * the kernel to boot_params.pref_address, or as low as
+	 * possible.
+	 */
+	start = hdr->pref_address;
+	nr_pages = round_up(hdr->init_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+
+	status = efi_call_phys4(sys_table->boottime->allocate_pages,
+				EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
+				nr_pages, &start);
+	if (status != EFI_SUCCESS) {
+		status = efi_low_alloc(sys_table, hdr->init_size,
+				   hdr->kernel_alignment, &start);
+		if (status != EFI_SUCCESS)
+			efi_printk(sys_table, "Failed to alloc mem for kernel\n");
+	}
+
+	if (status == EFI_SUCCESS)
+		memcpy((void *)start, (void *)(unsigned long)hdr->code32_start,
+		       hdr->init_size);
+
+	hdr->pref_address = hdr->code32_start;
+	hdr->code32_start = (__u32)start;
+
+	return status;
+}