From: Denis Mukhin <[email protected]> Introduce bootcount device backed by GPT PTE attributes (bits 48:63).
Signed-off-by: Denis Mukhin <[email protected]> --- drivers/bootcount/Kconfig | 7 ++ drivers/bootcount/Makefile | 1 + drivers/bootcount/bootcount-gpt.c | 140 ++++++++++++++++++++++++++++++ 3 files changed, 148 insertions(+) create mode 100644 drivers/bootcount/bootcount-gpt.c diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig index 4c0c8d89bb40..eccd610e3390 100644 --- a/drivers/bootcount/Kconfig +++ b/drivers/bootcount/Kconfig @@ -171,6 +171,13 @@ config DM_BOOTCOUNT_ZYNQMP Enable support for the bootcount API by utilising the Persistent Global General Storage Register 2 of the PMU. +config DM_BOOTCOUNT_GPT + bool "Support GPT PTE-backed boot counter" + depends on EFI_PARTITION + help + Add support for maintaining boot count within bits 48:63 of GUID + partition table entry attributes (similarly to ChromiumOS). + endmenu endif diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile index 0cf79e428d68..927694979801 100644 --- a/drivers/bootcount/Makefile +++ b/drivers/bootcount/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_DM_BOOTCOUNT_I2C) += bootcount_dm_i2c.o obj-$(CONFIG_DM_BOOTCOUNT_SPI_FLASH) += spi-flash.o obj-$(CONFIG_DM_BOOTCOUNT_SYSCON) += bootcount_syscon.o obj-$(CONFIG_DM_BOOTCOUNT_ZYNQMP) += bootcount_zynqmp.o +obj-$(CONFIG_DM_BOOTCOUNT_GPT) += bootcount-gpt.o diff --git a/drivers/bootcount/bootcount-gpt.c b/drivers/bootcount/bootcount-gpt.c new file mode 100644 index 000000000000..d2bbff2ba120 --- /dev/null +++ b/drivers/bootcount/bootcount-gpt.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#define pr_fmt(fmt) "bootcount-gpt: " fmt +#define LOG_CATEGORY UCLASS_BOOTCOUNT + +#include <blk.h> +#include <bootcount.h> +#include <dm.h> +#include <linux/printk.h> +#include <part.h> + +struct bootcount_gpt_priv { + struct blk_desc *blk_desc; + const char *partition_name; + int uclass_id; + int devnum; + int partnum; +}; + +static int bootcount_gpt_find(struct udevice *dev) +{ + struct bootcount_gpt_priv *priv = dev_get_priv(dev); + struct udevice *bdev; + struct disk_partition info; + int partnum, rc; + + rc = blk_get_device(priv->uclass_id, priv->devnum, &bdev); + if (rc < 0) + return -ENODEV; + + partnum = part_get_info_by_name(dev_get_uclass_plat(bdev), + priv->partition_name, &info); + if (partnum < 0) + return -ENODEV; + + if (info.bootable & PART_BOOTABLE) { + pr_warn("partition %s: legacy boot flag enabled, no GPT accounting\n", + priv->partition_name); + return -EPERM; + } + + priv->blk_desc = dev_get_uclass_plat(bdev); + priv->partnum = partnum; + + return 0; +} + +static int bootcount_gpt_get(struct udevice *dev, u32 *val) +{ + struct bootcount_gpt_priv *priv = dev_get_priv(dev); + int rc; + + if (!priv->blk_desc) { + rc = bootcount_gpt_find(dev); + if (rc < 0) + return rc; + } + + rc = read_disk_flags(priv->blk_desc, priv->partnum, (u16 *)val); + if (rc < 0) { + pr_err("partnum %d: failed to read GPT flags: %d\n", + priv->partnum, rc); + return rc; + } + + pr_debug("partnum %d: read GPT flags 0x%04x\n", priv->partnum, *val); + + return 0; +} + +static int bootcount_gpt_set(struct udevice *dev, const u32 val) +{ + struct bootcount_gpt_priv *priv = dev_get_priv(dev); + int rc; + + if (!priv->blk_desc) { + rc = bootcount_gpt_find(dev); + if (rc < 0) + return rc; + } + + pr_debug("partnum %d: write GPT flags 0x%04x\n", priv->partnum, val); + + rc = write_disk_flags(priv->blk_desc, priv->partnum, (u16)val); + if (rc < 0) { + pr_err("partnum %d: failed to write GPT flags: %d\n", + priv->partnum, rc); + return rc; + } + + return 0; +} + +static int bootcount_gpt_probe(struct udevice *dev) +{ + struct bootcount_gpt_priv *priv = dev_get_priv(dev); + const char *str; + int uclass_id, devnum; + + str = dev_read_string(dev, "device-type"); + if (!str) + return -ENOSYS; + + uclass_id = uclass_get_by_name(str); + if (uclass_id == UCLASS_INVALID) + return -ENOSYS; + + devnum = dev_read_s32_default(dev, "devnum", 0); + if (devnum < 0) + return -ENOSYS; + + str = dev_read_string(dev, "partition-name"); + if (!str) + return -ENOSYS; + + priv->uclass_id = uclass_id; + priv->devnum = devnum; + priv->partition_name = str; + + return 0; +} + +static const struct bootcount_ops bootcount_gpt_ops = { + .get = bootcount_gpt_get, + .set = bootcount_gpt_set, +}; + +static const struct udevice_id bootcount_gpt_ids[] = { + { .compatible = "u-boot,bootcount-gpt" }, + { } +}; + +U_BOOT_DRIVER(bootcount_gpt) = { + .name = "bootcount-gpt", + .id = UCLASS_BOOTCOUNT, + .priv_auto = sizeof(struct bootcount_gpt_priv), + .probe = bootcount_gpt_probe, + .of_match = bootcount_gpt_ids, + .ops = &bootcount_gpt_ops, +}; -- 2.54.0
