From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 15 Jan 2026 13:08:27 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vgM9L-001aHX-2r for lore@lore.pengutronix.de; Thu, 15 Jan 2026 13:08:27 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1vgM9K-0002be-G4 for lore@pengutronix.de; Thu, 15 Jan 2026 13:08:27 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XELL1Qm+QMR5g19NpyMq/AqNHmpftE4MNJbKX7elfTU=; b=BcNtGUIoQhYth4Uk2uO7RgPLWS ewwvwuLNPFapspnN2M9CzzBhk3V370FTReoiKQG8OlIfjfXIGVMJpr96bLvRCl9I0Dp8uc2lS0XH0 10Y/DGxqrgfmJP2oItQapdjSHjCwfak6dOzPU6sUn7YPGW4uRIgURWuWxXmQB126TS3jau0z06MCG 8Q0XOhoCpxpQUQrKv824DfoQO4dpi1/jZ4MMSYj0UGswrEf6qKGNJqK2b0FWYimMpBM14tch1lGlz KWAXwDuU0CC6R13EOtPQKcPcg1Eo9sjE+Tu/KZO8UDWKmR0sQEnyYPsOR2xDZnqP5nuTxPMq+JYxu s7apTH9A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgM8q-0000000CIYC-3oys; Thu, 15 Jan 2026 12:07:56 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgM8m-0000000CITp-2lC2 for barebox@lists.infradead.org; Thu, 15 Jan 2026 12:07:54 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=geraet.lan) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1vgM8l-0002HG-1O; Thu, 15 Jan 2026 13:07:51 +0100 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Thu, 15 Jan 2026 13:06:12 +0100 Message-ID: <20260115120748.3433463-5-a.fatoum@barebox.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260115120748.3433463-1-a.fatoum@barebox.org> References: <20260115120748.3433463-1-a.fatoum@barebox.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260115_040752_858211_E7285365 X-CRM114-Status: GOOD ( 21.74 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-3.8 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 4/6] common: boards: qemu: process some standard fw_cfg keys X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) While we have FW_CFG support as file system, there is a number of keys that precede the keys in the file system, which can be useful in some scenarios. Add support for QEMU -uuid, -kernel, -initrd, -append options as well as a /boot/qemu_fw_cfg script that continues booting according to the latter three options. Signed-off-by: Ahmad Fatoum --- common/boards/Kconfig | 8 + common/boards/Makefile | 1 + common/boards/qemu/Makefile | 4 + .../defaultenv-qemu_fw_cfg/boot/qemu_fw_cfg | 12 + common/boards/qemu/fw_cfg.c | 208 ++++++++++++++++++ drivers/firmware/Kconfig | 1 + 6 files changed, 234 insertions(+) create mode 100644 common/boards/qemu/Makefile create mode 100755 common/boards/qemu/defaultenv-qemu_fw_cfg/boot/qemu_fw_cfg create mode 100644 common/boards/qemu/fw_cfg.c diff --git a/common/boards/Kconfig b/common/boards/Kconfig index 74947316954b..a9e1b75a7641 100644 --- a/common/boards/Kconfig +++ b/common/boards/Kconfig @@ -1,5 +1,13 @@ # SPDX-License-Identifier: GPL-2.0-only +config BOARD_QEMU + bool "Extra support for QEMU-emulated boards" if COMPILE_TEST + +config BOARD_QEMU_VIRT + bool + select OF_OVERLAY + select BOARD_QEMU + config BOARD_QEMU_VIRT bool select OF_OVERLAY diff --git a/common/boards/Makefile b/common/boards/Makefile index 058733522411..86d07e04a2ad 100644 --- a/common/boards/Makefile +++ b/common/boards/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_BOARD_QEMU) += qemu/ obj-$(CONFIG_BOARD_QEMU_VIRT) += qemu-virt/ obj-$(CONFIG_BOARD_PHYTEC_SOM_DETECTION) += phytec/ obj-$(CONFIG_BOARD_TQ) += tq/ diff --git a/common/boards/qemu/Makefile b/common/boards/qemu/Makefile new file mode 100644 index 000000000000..2ea91d194bfc --- /dev/null +++ b/common/boards/qemu/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_QEMU_FW_CFG) += fw_cfg.o +bbenv-$(CONFIG_QEMU_FW_CFG) += defaultenv-qemu_fw_cfg diff --git a/common/boards/qemu/defaultenv-qemu_fw_cfg/boot/qemu_fw_cfg b/common/boards/qemu/defaultenv-qemu_fw_cfg/boot/qemu_fw_cfg new file mode 100755 index 000000000000..a3c12df67ff5 --- /dev/null +++ b/common/boards/qemu/defaultenv-qemu_fw_cfg/boot/qemu_fw_cfg @@ -0,0 +1,12 @@ +#!/bin/sh + +global.bootm.image=/dev/fw_cfg.kernel + +if [ -s /dev/fw_cfg.initrd ]; then + global.bootm.initrd=/dev/fw_cfg.initrd +fi + +if [ -s /dev/fw_cfg.cmdline ]; then + readf /dev/fw_cfg.initrd qemu_fw_cfg_cmdline + global linux.bootargs.dyn.qemu="${qemu_fw_cfg_cmdline}" +fi diff --git a/common/boards/qemu/fw_cfg.c b/common/boards/qemu/fw_cfg.c new file mode 100644 index 000000000000..d0900b2ab7c3 --- /dev/null +++ b/common/boards/qemu/fw_cfg.c @@ -0,0 +1,208 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Common QEMU fw_cfg board code */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct fw_cfg_cdev { + struct cdev cdev; + u16 size_selector; + u16 data_selector; + void *cache; + size_t cached_size; /* How many bytes from start are cached */ +}; + +static struct fw_cfg_cdev *to_fw_cfg_cdev(struct cdev *cdev) +{ + return container_of(cdev, struct fw_cfg_cdev, cdev); +} + +static int qemu_fw_cfg_read(int fd, u16 selector, void *buf, size_t size) +{ + ssize_t ret; + + ret = ioctl(fd, FW_CFG_SELECT, &selector); + if (ret || !buf) + return ret; + + ret = pread(fd, buf, size, 0); + return ret < 0 ? ret : 0; +} + +static ssize_t fw_cfg_cdev_read(struct cdev *cdev, void *buf, size_t count, + loff_t offset, ulong flags) +{ + struct fw_cfg_cdev *fcc = to_fw_cfg_cdev(cdev); + size_t end_pos = offset + count; + size_t to_read, to_copy; + int ret; + + /* Bounds check */ + if (offset >= cdev->size) + return 0; + + if (end_pos > cdev->size) + end_pos = cdev->size; + + count = end_pos - offset; + + /* Allocate cache on first read */ + if (!fcc->cache) { + fcc->cache = malloc(cdev->size); + if (!fcc->cache) + return -ENOMEM; + fcc->cached_size = 0; + } + + /* Extend cache if needed */ + if (end_pos > fcc->cached_size) { + int fd; + + to_read = end_pos - fcc->cached_size; + + fd = open("/dev/fw_cfg", O_RDWR); + if (fd < 0) + return fd; + + ret = qemu_fw_cfg_read(fd, fcc->data_selector, + fcc->cache + fcc->cached_size, to_read); + + close(fd); + + if (ret) + return ret; + + fcc->cached_size = end_pos; + } + + /* Copy from cache to user buffer */ + to_copy = count; + + if (buf) + memcpy(buf, fcc->cache + offset, to_copy); + + return to_copy; +} + +static int fw_cfg_cdev_mmap(struct cdev *cdev, void **map, int flags) +{ + struct fw_cfg_cdev *fcc = to_fw_cfg_cdev(cdev); + ssize_t ret; + + if (flags & PROT_WRITE) + return -EACCES; + + ret = fw_cfg_cdev_read(cdev, NULL, ~0, 0, 0); + if (ret == 0) + ret = -EINVAL; + if (ret < 0) + return ret; + + *map = fcc->cache; + + return PTR_ERR_OR_ZERO(*map); +} + +static int fw_cfg_cdev_flush(struct cdev *cdev) +{ + struct fw_cfg_cdev *fcc = to_fw_cfg_cdev(cdev); + + if (fcc->cache) { + free(fcc->cache); + fcc->cache = NULL; + fcc->cached_size = 0; + } + + return 0; +} + +static struct cdev_operations fw_cfg_cdev_ops = { + .read = fw_cfg_cdev_read, + .flush = fw_cfg_cdev_flush, + .memmap = fw_cfg_cdev_mmap, +}; + +static int fw_cfg_register_cdev(int fd, const char *name, + u16 size_selector, u16 data_selector) +{ + struct fw_cfg_cdev *fcc; + u32 size; + int ret; + + /* Read size upfront */ + ret = qemu_fw_cfg_read(fd, size_selector, &size, sizeof(size)); + if (!ret && !size) + ret = -ENOENT; + if (ret < 0) + return ret; + + fcc = xzalloc(sizeof(*fcc)); + fcc->size_selector = size_selector; + fcc->data_selector = data_selector; + fcc->cache = xzalloc(size); + fcc->cached_size = size; + + ret = qemu_fw_cfg_read(fd, data_selector, + fcc->cache, fcc->cached_size); + if (ret) + return ret; + + fcc->cdev.name = xstrdup(name); + fcc->cdev.size = size; + fcc->cdev.ops = &fw_cfg_cdev_ops; + + ret = devfs_create(&fcc->cdev); + if (ret < 0) { + free(fcc->cdev.name); + free(fcc); + return ret; + } + + return 0; +} + +static int qemu_fw_cfg_boot_init(void) +{ + struct { + const char prefix[16]; + uuid_t uuid; + } machine_hashable = { "qemubareboxuuid"}; + __always_unused size_t size; + int fd, ret; + + fd = open("/dev/fw_cfg", O_RDWR); + if (fd < 0) + return 0; + + /* Specified by -uuid. Zero by default */ + ret = qemu_fw_cfg_read(fd, FW_CFG_UUID, &machine_hashable.uuid, + sizeof(machine_hashable.uuid)); + if (!ret) { + barebox_set_product_uuid(&machine_hashable.uuid); + if (!machine_id_get_hashable(&size)) + machine_id_set_hashable(&machine_hashable, sizeof(machine_hashable)); + } + + /* Register fw_cfg cdevs */ + fw_cfg_register_cdev(fd, "fw_cfg.kernel", FW_CFG_KERNEL_SIZE, FW_CFG_KERNEL_DATA); + fw_cfg_register_cdev(fd, "fw_cfg.initrd", FW_CFG_INITRD_SIZE, FW_CFG_INITRD_DATA); + fw_cfg_register_cdev(fd, "fw_cfg.cmdline", FW_CFG_CMDLINE_SIZE, FW_CFG_CMDLINE_DATA); + + defaultenv_append_directory(defaultenv_qemu_fw_cfg); + + /* Reset cdev to beginning */ + ret = qemu_fw_cfg_read(fd, FW_CFG_SIGNATURE, NULL, 0); + if (ret) + return ret; + + close(fd); + return 0; +} +crypto_initcall(qemu_fw_cfg_boot_init); diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 649b80ac289c..d7bf1d78937a 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -45,6 +45,7 @@ config FIRMWARE_ZYNQ7000_FPGA config QEMU_FW_CFG bool "QEMU FW CFG interface" + select BOARD_QEMU help This driver exposes the QEMU FW CFG conduit as a single character device. -- 2.47.3