Linux-libre 4.5-gnu

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
new file mode 100644
index 000000000..495ebd657
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2013 Linaro Ltd;  <roy.franz@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
+				 unsigned long *image_addr,
+				 unsigned long *image_size,
+				 unsigned long *reserve_addr,
+				 unsigned long *reserve_size,
+				 unsigned long dram_base,
+				 efi_loaded_image_t *image)
+{
+	unsigned long nr_pages;
+	efi_status_t status;
+	/* Use alloc_addr to tranlsate between types */
+	efi_physical_addr_t alloc_addr;
+
+	/*
+	 * Verify that the DRAM base address is compatible with the ARM
+	 * boot protocol, which determines the base of DRAM by masking
+	 * off the low 27 bits of the address at which the zImage is
+	 * loaded. These assumptions are made by the decompressor,
+	 * before any memory map is available.
+	 */
+	dram_base = round_up(dram_base, SZ_128M);
+
+	/*
+	 * Reserve memory for the uncompressed kernel image. This is
+	 * all that prevents any future allocations from conflicting
+	 * with the kernel. Since we can't tell from the compressed
+	 * image how much DRAM the kernel actually uses (due to BSS
+	 * size uncertainty) we allocate the maximum possible size.
+	 * Do this very early, as prints can cause memory allocations
+	 * that may conflict with this.
+	 */
+	alloc_addr = dram_base;
+	*reserve_size = MAX_UNCOMP_KERNEL_SIZE;
+	nr_pages = round_up(*reserve_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
+	status = sys_table->boottime->allocate_pages(EFI_ALLOCATE_ADDRESS,
+						     EFI_LOADER_DATA,
+						     nr_pages, &alloc_addr);
+	if (status != EFI_SUCCESS) {
+		*reserve_size = 0;
+		pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n");
+		return status;
+	}
+	*reserve_addr = alloc_addr;
+
+	/*
+	 * Relocate the zImage, so that it appears in the lowest 128 MB
+	 * memory window.
+	 */
+	*image_size = image->image_size;
+	status = efi_relocate_kernel(sys_table, image_addr, *image_size,
+				     *image_size,
+				     dram_base + MAX_UNCOMP_KERNEL_SIZE, 0);
+	if (status != EFI_SUCCESS) {
+		pr_efi_err(sys_table, "Failed to relocate kernel.\n");
+		efi_free(sys_table, *reserve_size, *reserve_addr);
+		*reserve_size = 0;
+		return status;
+	}
+
+	/*
+	 * Check to see if we were able to allocate memory low enough
+	 * in memory. The kernel determines the base of DRAM from the
+	 * address at which the zImage is loaded.
+	 */
+	if (*image_addr + *image_size > dram_base + ZIMAGE_OFFSET_LIMIT) {
+		pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n");
+		efi_free(sys_table, *reserve_size, *reserve_addr);
+		*reserve_size = 0;
+		efi_free(sys_table, *image_size, *image_addr);
+		*image_size = 0;
+		return EFI_LOAD_ERROR;
+	}
+	return EFI_SUCCESS;
+}