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path: root/drivers/firmware/efi/libstub/arm-stub.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/arm-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
new file mode 100644
index 000000000..e29560e6b
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -0,0 +1,355 @@
+/*
+ * EFI stub implementation that is shared by arm and arm64 architectures.
+ * This should be #included by the EFI stub implementation files.
+ *
+ * Copyright (C) 2013,2014 Linaro Limited
+ * Roy Franz <roy.franz@linaro.org
+ * Copyright (C) 2013 Red Hat, Inc.
+ * Mark Salter <msalter@redhat.com>
+ *
+ * This file is part of the Linux kernel, and is made available under the
+ * terms of the GNU General Public License version 2.
+ *
+ */
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
+{
+ static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
+ static efi_char16_t const var_name[] = {
+ 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
+
+ efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
+ unsigned long size = sizeof(u8);
+ efi_status_t status;
+ u8 val;
+
+ status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid,
+ NULL, &size, &val);
+
+ switch (status) {
+ case EFI_SUCCESS:
+ return val;
+ case EFI_NOT_FOUND:
+ return 0;
+ default:
+ return 1;
+ }
+}
+
+efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
+ void *__image, void **__fh)
+{
+ efi_file_io_interface_t *io;
+ efi_loaded_image_t *image = __image;
+ efi_file_handle_t *fh;
+ efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
+ efi_status_t status;
+ void *handle = (void *)(unsigned long)image->device_handle;
+
+ status = sys_table_arg->boottime->handle_protocol(handle,
+ &fs_proto, (void **)&io);
+ if (status != EFI_SUCCESS) {
+ efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
+ return status;
+ }
+
+ status = io->open_volume(io, &fh);
+ if (status != EFI_SUCCESS)
+ efi_printk(sys_table_arg, "Failed to open volume\n");
+
+ *__fh = fh;
+ return status;
+}
+
+efi_status_t efi_file_close(void *handle)
+{
+ efi_file_handle_t *fh = handle;
+
+ return fh->close(handle);
+}
+
+efi_status_t
+efi_file_read(void *handle, unsigned long *size, void *addr)
+{
+ efi_file_handle_t *fh = handle;
+
+ return fh->read(handle, size, addr);
+}
+
+
+efi_status_t
+efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
+ efi_char16_t *filename_16, void **handle, u64 *file_sz)
+{
+ efi_file_handle_t *h, *fh = __fh;
+ efi_file_info_t *info;
+ efi_status_t status;
+ efi_guid_t info_guid = EFI_FILE_INFO_ID;
+ unsigned long info_sz;
+
+ status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, (u64)0);
+ if (status != EFI_SUCCESS) {
+ efi_printk(sys_table_arg, "Failed to open file: ");
+ efi_char16_printk(sys_table_arg, filename_16);
+ efi_printk(sys_table_arg, "\n");
+ return status;
+ }
+
+ *handle = h;
+
+ info_sz = 0;
+ status = h->get_info(h, &info_guid, &info_sz, NULL);
+ if (status != EFI_BUFFER_TOO_SMALL) {
+ efi_printk(sys_table_arg, "Failed to get file info size\n");
+ return status;
+ }
+
+grow:
+ status = sys_table_arg->boottime->allocate_pool(EFI_LOADER_DATA,
+ info_sz, (void **)&info);
+ if (status != EFI_SUCCESS) {
+ efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
+ return status;
+ }
+
+ status = h->get_info(h, &info_guid, &info_sz,
+ info);
+ if (status == EFI_BUFFER_TOO_SMALL) {
+ sys_table_arg->boottime->free_pool(info);
+ goto grow;
+ }
+
+ *file_sz = info->file_size;
+ sys_table_arg->boottime->free_pool(info);
+
+ if (status != EFI_SUCCESS)
+ efi_printk(sys_table_arg, "Failed to get initrd info\n");
+
+ return status;
+}
+
+
+
+void efi_char16_printk(efi_system_table_t *sys_table_arg,
+ efi_char16_t *str)
+{
+ struct efi_simple_text_output_protocol *out;
+
+ out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
+ out->output_string(out, str);
+}
+
+
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+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);
+/*
+ * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
+ * that is described in the PE/COFF header. Most of the code is the same
+ * for both archictectures, with the arch-specific code provided in the
+ * handle_kernel_image() function.
+ */
+unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
+ unsigned long *image_addr)
+{
+ efi_loaded_image_t *image;
+ efi_status_t status;
+ unsigned long image_size = 0;
+ unsigned long dram_base;
+ /* addr/point and size pairs for memory management*/
+ unsigned long initrd_addr;
+ u64 initrd_size = 0;
+ unsigned long fdt_addr = 0; /* Original DTB */
+ unsigned long fdt_size = 0;
+ char *cmdline_ptr = NULL;
+ int cmdline_size = 0;
+ unsigned long new_fdt_addr;
+ efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
+ unsigned long reserve_addr = 0;
+ unsigned long reserve_size = 0;
+
+ /* Check if we were booted by the EFI firmware */
+ if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+ goto fail;
+
+ pr_efi(sys_table, "Booting Linux Kernel...\n");
+
+ /*
+ * Get a handle to the loaded image protocol. This is used to get
+ * information about the running image, such as size and the command
+ * line.
+ */
+ status = sys_table->boottime->handle_protocol(handle,
+ &loaded_image_proto, (void *)&image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
+ goto fail;
+ }
+
+ dram_base = get_dram_base(sys_table);
+ if (dram_base == EFI_ERROR) {
+ pr_efi_err(sys_table, "Failed to find DRAM base\n");
+ goto fail;
+ }
+ status = handle_kernel_image(sys_table, image_addr, &image_size,
+ &reserve_addr,
+ &reserve_size,
+ dram_base, image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to relocate kernel\n");
+ goto fail;
+ }
+
+ /*
+ * Get the command line from EFI, using the LOADED_IMAGE
+ * protocol. We are going to copy the command line into the
+ * device tree, so this can be allocated anywhere.
+ */
+ cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
+ if (!cmdline_ptr) {
+ pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
+ goto fail_free_image;
+ }
+
+ status = efi_parse_options(cmdline_ptr);
+ if (status != EFI_SUCCESS)
+ pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
+
+ /*
+ * Unauthenticated device tree data is a security hazard, so
+ * ignore 'dtb=' unless UEFI Secure Boot is disabled.
+ */
+ if (efi_secureboot_enabled(sys_table)) {
+ pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
+ } else {
+ status = handle_cmdline_files(sys_table, image, cmdline_ptr,
+ "dtb=",
+ ~0UL, &fdt_addr, &fdt_size);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to load device tree!\n");
+ goto fail_free_cmdline;
+ }
+ }
+
+ if (fdt_addr) {
+ pr_efi(sys_table, "Using DTB from command line\n");
+ } else {
+ /* Look for a device tree configuration table entry. */
+ fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
+ if (fdt_addr)
+ pr_efi(sys_table, "Using DTB from configuration table\n");
+ }
+
+ if (!fdt_addr)
+ pr_efi(sys_table, "Generating empty DTB\n");
+
+ status = handle_cmdline_files(sys_table, image, cmdline_ptr,
+ "initrd=", dram_base + SZ_512M,
+ (unsigned long *)&initrd_addr,
+ (unsigned long *)&initrd_size);
+ if (status != EFI_SUCCESS)
+ pr_efi_err(sys_table, "Failed initrd from command line!\n");
+
+ new_fdt_addr = fdt_addr;
+ status = allocate_new_fdt_and_exit_boot(sys_table, handle,
+ &new_fdt_addr, dram_base + MAX_FDT_OFFSET,
+ initrd_addr, initrd_size, cmdline_ptr,
+ fdt_addr, fdt_size);
+
+ /*
+ * If all went well, we need to return the FDT address to the
+ * calling function so it can be passed to kernel as part of
+ * the kernel boot protocol.
+ */
+ if (status == EFI_SUCCESS)
+ return new_fdt_addr;
+
+ pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
+
+ efi_free(sys_table, initrd_size, initrd_addr);
+ efi_free(sys_table, fdt_size, fdt_addr);
+
+fail_free_cmdline:
+ efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
+
+fail_free_image:
+ efi_free(sys_table, image_size, *image_addr);
+ efi_free(sys_table, reserve_size, reserve_addr);
+fail:
+ return EFI_ERROR;
+}
+
+/*
+ * This is the base address at which to start allocating virtual memory ranges
+ * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * any allocation we choose, and eliminate the risk of a conflict after kexec.
+ * The value chosen is the largest non-zero power of 2 suitable for this purpose
+ * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
+ * be mapped efficiently.
+ */
+#define EFI_RT_VIRTUAL_BASE 0x40000000
+
+/*
+ * efi_get_virtmap() - create a virtual mapping for the EFI memory map
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
+ unsigned long desc_size, efi_memory_desc_t *runtime_map,
+ int *count)
+{
+ u64 efi_virt_base = EFI_RT_VIRTUAL_BASE;
+ efi_memory_desc_t *out = runtime_map;
+ int l;
+
+ for (l = 0; l < map_size; l += desc_size) {
+ efi_memory_desc_t *in = (void *)memory_map + l;
+ u64 paddr, size;
+
+ if (!(in->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ /*
+ * Make the mapping compatible with 64k pages: this allows
+ * a 4k page size kernel to kexec a 64k page size kernel and
+ * vice versa.
+ */
+ paddr = round_down(in->phys_addr, SZ_64K);
+ size = round_up(in->num_pages * EFI_PAGE_SIZE +
+ in->phys_addr - paddr, SZ_64K);
+
+ /*
+ * Avoid wasting memory on PTEs by choosing a virtual base that
+ * is compatible with section mappings if this region has the
+ * appropriate size and physical alignment. (Sections are 2 MB
+ * on 4k granule kernels)
+ */
+ if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
+ efi_virt_base = round_up(efi_virt_base, SZ_2M);
+
+ in->virt_addr = efi_virt_base + in->phys_addr - paddr;
+ efi_virt_base += size;
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}