1 files changed, 278 insertions, 0 deletions

diff --git a/drivers/firmware/efi/arm-stub.c b/drivers/firmware/efi/arm-stub.c
new file mode 100644
index 000000000000..41114ce03b01
--- /dev/null
+++ b/drivers/firmware/efi/arm-stub.c
@@ -0,0 +1,278 @@
+/*
+ * 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.
+ *
+ */
+
+static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
+{
+        static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
+        static efi_char16_t const var_name[] __initconst = {
+                '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;
+        }
+}
+
+static 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;
+}
+static efi_status_t efi_file_close(void *handle)
+{
+        efi_file_handle_t *fh = handle;
+
+        return fh->close(handle);
+}
+
+static 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);
+}
+
+
+static 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;
+}
+
+
+
+static 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.
+ */
+static 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 __init 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 */
+        u64 fdt_size = 0;  /* We don't get size from configuration table */
+        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;
+        }
+
+        /*
+         * 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, (unsigned long *)&fdt_addr,
+                                              (unsigned long *)&fdt_size);
+
+                if (status != EFI_SUCCESS) {
+                        pr_efi_err(sys_table, "Failed to load device tree!\n");
+                        goto fail_free_cmdline;
+                }
+        }
+        if (!fdt_addr)
+                /* Look for a device tree configuration table entry. */
+                fdt_addr = (uintptr_t)get_fdt(sys_table);
+
+        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;
+}