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path: root/drivers/firmware/efi/libstub/arm32-stub.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/arm32-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm32-stub.c85
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 000000000000..495ebd657e38
--- /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;
+}