From: "Kweh, Hock Leong" <[email protected]> Introducing a kernel module to expose capsule loader interface for user to upload capsule binaries. This module leverage the request_firmware_direct_full_path() to obtain the binary at a specific path input by user.
Example method to load the capsule binary: echo -n "/path/to/capsule/binary" > /sys/devices/platform/efi_capsule_loader/capsule_loader Cc: Matt Fleming <[email protected]> Signed-off-by: Kweh, Hock Leong <[email protected]> --- drivers/firmware/efi/Kconfig | 12 ++ drivers/firmware/efi/Makefile | 1 + drivers/firmware/efi/efi-capsule-loader.c | 169 +++++++++++++++++++++++++++++ 3 files changed, 182 insertions(+) create mode 100644 drivers/firmware/efi/efi-capsule-loader.c diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index f712d47..3e84ec0 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -60,6 +60,18 @@ config EFI_RUNTIME_WRAPPERS config EFI_ARMSTUB bool +config EFI_CAPSULE_LOADER + tristate "EFI capsule loader" + depends on EFI + select FW_LOADER + help + This option exposes a loader interface for user to load EFI + capsule binary and update the EFI firmware through system reboot. + This feature does not support auto locating capsule binaries at the + firmware lib search path. + + If unsure, say N. + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 698846e..5ab031a 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_UEFI_CPER) += cper.o obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o obj-$(CONFIG_EFI_STUB) += libstub/ +obj-$(CONFIG_EFI_CAPSULE_LOADER) += efi-capsule-loader.o diff --git a/drivers/firmware/efi/efi-capsule-loader.c b/drivers/firmware/efi/efi-capsule-loader.c new file mode 100644 index 0000000..84b979b --- /dev/null +++ b/drivers/firmware/efi/efi-capsule-loader.c @@ -0,0 +1,169 @@ +/* + * EFI capsule loader driver. + * + * Copyright 2015 Intel Corporation + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/efi.h> +#include <linux/firmware.h> + +#define DEV_NAME "efi_capsule_loader" + +static DEFINE_MUTEX(capsule_loader_lock); +static struct platform_device *efi_capsule_pdev; + +/* + * This function will store the capsule binary and pass it to + * efi_capsule_update() API in capsule.c + */ +static int efi_capsule_store(const struct firmware *fw) +{ + int i; + int ret; + int count = fw->size; + int copy_size = (fw->size > PAGE_SIZE) ? PAGE_SIZE : fw->size; + int pages_needed = ALIGN(fw->size, PAGE_SIZE) >> PAGE_SHIFT; + struct page **pages; + void *page_data; + efi_capsule_header_t *capsule = NULL; + + if (!count) { + pr_err("%s: Received zero binary size\n", __func__); + return -ENOENT; + } + + pages = kmalloc_array(pages_needed, sizeof(void *), GFP_KERNEL); + if (!pages) { + pr_err("%s: kmalloc_array() failed\n", __func__); + return -ENOMEM; + } + + for (i = 0; i < pages_needed; i++) { + pages[i] = alloc_page(GFP_KERNEL); + if (!pages[i]) { + pr_err("%s: alloc_page() failed\n", __func__); + --i; + ret = -ENOMEM; + goto failed; + } + } + + for (i = 0; i < pages_needed; i++) { + page_data = kmap(pages[i]); + memcpy(page_data, fw->data + (i * PAGE_SIZE), copy_size); + + if (i == 0) + capsule = (efi_capsule_header_t *)page_data; + else + kunmap(pages[i]); + + count -= copy_size; + if (count < PAGE_SIZE) + copy_size = count; + } + + ret = efi_capsule_update(capsule, pages); + if (ret) { + pr_err("%s: efi_capsule_update() failed\n", __func__); + --i; + goto failed; + } + kunmap(pages[0]); + + /* + * we cannot free the pages here due to reboot need that data + * maintained. + */ + return 0; + +failed: + while (i >= 0) + __free_page(pages[i--]); + kfree(pages); + return ret; +} + +static ssize_t capsule_loader_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret = -EBUSY; + const struct firmware *fw; + + pr_debug("%s: Received path = %s\n", __func__, buf); + if (mutex_trylock(&capsule_loader_lock)) { + ret = request_firmware_direct_full_path(&fw, buf, + &efi_capsule_pdev->dev); + if (ret) { + pr_err("%s: request_firmware_direct_full_path() %s\n", + __func__, + "failed"); + mutex_unlock(&capsule_loader_lock); + return ret; + } + + ret = efi_capsule_store(fw); + if (ret) + pr_err("%s: %s, return error code = %d\n", + __func__, + "Failed to store capsule binary", + ret); + release_firmware(fw); + mutex_unlock(&capsule_loader_lock); + } + + return ret ? ret : count; +} +static DEVICE_ATTR_WO(capsule_loader); + +static int __init efi_capsule_loader_init(void) +{ + int ret = 0; + + efi_capsule_pdev = platform_device_register_simple(DEV_NAME, + PLATFORM_DEVID_NONE, + NULL, 0); + if (IS_ERR(efi_capsule_pdev)) { + pr_err("%s: platform_device_register_simple() failed\n", + __func__); + return PTR_ERR(efi_capsule_pdev); + } + + /* + * create this file node for user to pass in the full path of the + * capsule binary + */ + ret = device_create_file(&efi_capsule_pdev->dev, + &dev_attr_capsule_loader); + if (ret) { + pr_err("%s: device_create_file() failed\n", __func__); + platform_device_unregister(efi_capsule_pdev); + } + + return ret; +} +module_init(efi_capsule_loader_init); + +/* + * To remove this kernel module, just perform: + * rmmod efi_capsule_loader.ko + */ +static void __exit efi_capsule_loader_exit(void) +{ + platform_device_unregister(efi_capsule_pdev); +} +module_exit(efi_capsule_loader_exit); + +MODULE_DESCRIPTION("EFI capsule firmware binary loader"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
