[U-Boot] [PATCH v1 05/15] efi_loader: add device-path utils
Heinrich Schuchardt
xypron.glpk at gmx.de
Fri Aug 11 16:49:52 UTC 2017
On 08/10/2017 08:29 PM, Rob Clark wrote:
> Helpers to construct device-paths from devices, partitions, files, and
> for parsing and manipulating device-paths.
>
> For non-legacy devices, this will use u-boot's device-model to construct
> device-paths which include bus hierarchy to construct device-paths. For
> legacy devices we still fake it, but slightly more convincingly.
>
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
> include/efi_api.h | 10 +
> include/efi_loader.h | 20 ++
> lib/efi_loader/Makefile | 2 +-
> lib/efi_loader/efi_device_path.c | 489 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 520 insertions(+), 1 deletion(-)
> create mode 100644 lib/efi_loader/efi_device_path.c
>
> diff --git a/include/efi_api.h b/include/efi_api.h
> index b761cf4822..4e27c82129 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -314,6 +314,7 @@ struct efi_device_path_acpi_path {
> #define DEVICE_PATH_TYPE_MESSAGING_DEVICE 0x03
> # define DEVICE_PATH_SUB_TYPE_MSG_USB 0x05
> # define DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR 0x0b
> +# define DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS 0x0f
> # define DEVICE_PATH_SUB_TYPE_MSG_SD 0x1a
> # define DEVICE_PATH_SUB_TYPE_MSG_MMC 0x1d
>
> @@ -329,6 +330,15 @@ struct efi_device_path_mac_addr {
> u8 if_type;
> } __packed;
>
> +struct efi_device_path_usb_class {
> + struct efi_device_path dp;
> + u16 vendor_id;
> + u16 product_id;
> + u8 device_class;
> + u8 device_subclass;
> + u8 device_protocol;
> +} __packed;
> +
> struct efi_device_path_sd_mmc_path {
> struct efi_device_path dp;
> u8 slot_number;
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 037cc7c543..bcca6e49ea 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -197,6 +197,26 @@ extern void *efi_bounce_buffer;
> #define EFI_LOADER_BOUNCE_BUFFER_SIZE (64 * 1024 * 1024)
> #endif
>
> +
> +struct efi_device_path *efi_dp_next(struct efi_device_path *dp);
> +int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b);
> +struct efi_object *efi_dp_find_obj(struct efi_device_path *dp);
> +unsigned efi_dp_size(struct efi_device_path *dp);
> +struct efi_device_path *efi_dp_dup(struct efi_device_path *dp);
> +
> +struct efi_device_path *efi_dp_from_dev(struct udevice *dev);
> +struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part);
> +struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
> + const char *path);
> +struct efi_device_path *efi_dp_from_eth(void);
> +void efi_dp_split_file_path(struct efi_device_path *full_path,
> + struct efi_device_path **device_path,
> + struct efi_device_path **file_path);
> +
> +#define EFI_DP_TYPE(_dp, _type, _subtype) \
> + (((_dp)->type == DEVICE_PATH_TYPE_##_type) && \
> + ((_dp)->sub_type == DEVICE_PATH_SUB_TYPE_##_subtype))
> +
> /* Convert strings from normal C strings to uEFI strings */
> static inline void ascii2unicode(u16 *unicode, const char *ascii)
> {
> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> index 30bf343a36..f35e5ce8a8 100644
> --- a/lib/efi_loader/Makefile
> +++ b/lib/efi_loader/Makefile
> @@ -15,7 +15,7 @@ always := $(efiprogs-y)
>
> obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
> obj-y += efi_image_loader.o efi_boottime.o efi_runtime.o efi_console.o
> -obj-y += efi_memory.o efi_device_path_to_text.o
> +obj-y += efi_memory.o efi_device_path_to_text.o efi_device_path.o
> obj-$(CONFIG_LCD) += efi_gop.o
> obj-$(CONFIG_DM_VIDEO) += efi_gop.o
> obj-$(CONFIG_PARTITIONS) += efi_disk.o
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> new file mode 100644
> index 0000000000..e8a6bbff82
> --- /dev/null
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -0,0 +1,489 @@
> +/*
> + * EFI device path from u-boot device-model mapping
> + *
> + * (C) Copyright 2017 Rob Clark
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <blk.h>
> +#include <dm.h>
> +#include <usb.h>
> +#include <mmc.h>
> +#include <efi_loader.h>
> +#include <inttypes.h>
> +#include <part.h>
> +#include <malloc.h>
> +
> +/* template END node: */
> +static const struct efi_device_path END = {
> + .type = DEVICE_PATH_TYPE_END,
> + .sub_type = DEVICE_PATH_SUB_TYPE_END,
> + .length = sizeof(END),
> +};
> +
> +#define U_BOOT_GUID \
> + EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
> + 0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b)
> +
> +/* template ROOT node, a fictional ACPI PNP device: */
> +static const struct efi_device_path_vendor ROOT = {
> + .dp = {
> + .type = DEVICE_PATH_TYPE_HARDWARE_DEVICE,
> + .sub_type = DEVICE_PATH_SUB_TYPE_VENDOR,
> + .length = sizeof(ROOT),
> + },
> + .guid = U_BOOT_GUID,
> +};
> +
> +
> +/*
> + * Iterate to next block in device-path, terminating (returning NULL)
> + * at /End* node.
> + */
> +struct efi_device_path *efi_dp_next(struct efi_device_path *dp)
> +{
> + if (dp == NULL)
> + return NULL;
> + dp = ((void *)dp) + dp->length;
> + if (dp->type == DEVICE_PATH_TYPE_END)
> + return NULL;
> + return dp;
> +}
> +
> +/*
> + * Compare two device-paths, stopping when the shorter of the two hits
> + * an End* node. This is useful to, for example, compare a device-path
> + * representing a device with one representing a file on the device, or
> + * a device with a parent device.
> + */
> +int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b)
> +{
> + while (1) {
> + int ret;
> +
> + ret = memcmp(&a->length, &b->length, sizeof(a->length));
> + if (ret)
> + return ret;
> +
> + ret = memcmp(a, b, a->length);
> + if (ret)
> + return ret;
> +
> + a = efi_dp_next(a);
> + b = efi_dp_next(b);
> +
> + if (!a || !b)
> + return 0;
> + }
> +}
> +
> +
> +/*
> + * See UEFI spec (section 3.1.2, about short-form device-paths..
> + * tl;dr: we can have a device-path that starts with a USB WWID
> + * or USB Class node, and a few other cases which don't encode
> + * the full device path with bus hierarchy:
> + *
> + * - MESSAGING:USB_WWID
> + * - MESSAGING:USB_CLASS
> + * - MEDIA:FILE_PATH
> + * - MEDIA:HARD_DRIVE
> + * - MESSAGING:URI
> + */
> +static struct efi_device_path *shorten_path(struct efi_device_path *dp)
> +{
> + while (dp) {
> + /*
> + * TODO: Add MESSAGING:USB_WWID and MESSAGING:URI..
> + * in practice fallback.efi just uses MEDIA:HARD_DRIVE
> + * so not sure when we would see these other cases.
> + */
> + if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) ||
> + EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) ||
> + EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH))
> + return dp;
> +
> + dp = efi_dp_next(dp);
> + }
> +
> + return dp;
> +}
> +
> +static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path)
> +{
> + struct efi_object *efiobj;
> +
> + list_for_each_entry(efiobj, &efi_obj_list, link) {
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) {
> + struct efi_handler *handler = &efiobj->protocols[i];
> + struct efi_device_path *obj_dp;
> +
> + if (!handler->guid)
> + break;
> +
> + if (guidcmp(handler->guid, &efi_guid_device_path))
> + continue;
> +
> + obj_dp = handler->protocol_interface;
> +
> + do {
> + if (efi_dp_match(dp, obj_dp) == 0)
> + return efiobj;
> +
> + obj_dp = shorten_path(efi_dp_next(obj_dp));
> + } while (short_path && obj_dp);
> + }
> + }
> +
> + return NULL;
> +}
> +
> +
> +/* Find an efiobj from device-path */
> +struct efi_object *efi_dp_find_obj(struct efi_device_path *dp)
> +{
> + struct efi_object *efiobj;
> +
> + efiobj = find_obj(dp, false);
> +
> + if (!efiobj)
> + efiobj = find_obj(dp, true);
> +
> + return efiobj;
> +}
> +
> +/* return size not including End node: */
> +unsigned efi_dp_size(struct efi_device_path *dp)
> +{
> + unsigned sz = 0;
> +
> + while (dp) {
> + sz += dp->length;
> + dp = efi_dp_next(dp);
> + }
> +
> + return sz;
> +}
> +
> +struct efi_device_path *efi_dp_dup(struct efi_device_path *dp)
> +{
> + struct efi_device_path *ndp;
> + unsigned sz = efi_dp_size(dp) + sizeof(struct efi_device_path);
> +
> + ndp = malloc(sz);
> + memcpy(ndp, dp, sz);
> +
> + return ndp;
> +}
> +
> +#ifdef CONFIG_DM
> +/* size of device-path not including END node for device and all parents
> + * up to the root device.
> + */
> +static unsigned dp_size(struct udevice *dev)
> +{
> + if (!dev || !dev->driver)
> + return sizeof(ROOT);
> +
> + switch (dev->driver->id) {
> + case UCLASS_ROOT:
> + case UCLASS_SIMPLE_BUS:
> + /* stop traversing parents at this point: */
> + return sizeof(ROOT);
> + case UCLASS_MMC:
> + return dp_size(dev->parent) + sizeof(struct efi_device_path_sd_mmc_path);
> + case UCLASS_MASS_STORAGE:
> + case UCLASS_USB_HUB:
> + return dp_size(dev->parent) + sizeof(struct efi_device_path_usb_class);
It seems you forgot to run scripts/checkpatch.pl for your patches:
Line over 80 characters. Please, use line break.
> + default:
> + /* just skip over unknown classes: */
> + return dp_size(dev->parent);
> + }
> +}
> +
> +static void *dp_fill(void *buf, struct udevice *dev)
> +{
> + if (!dev || !dev->driver)
> + return buf;
> +
> + switch (dev->driver->id) {
> + case UCLASS_ROOT:
> + case UCLASS_SIMPLE_BUS: {
> + /* stop traversing parents at this point: */
> + struct efi_device_path_vendor *vdp = buf;
> + *vdp = ROOT;
> + return &vdp[1];
> + }
> +#if defined(CONFIG_DM_MMC) && defined (CONFIG_MMC)
scripts/checkpatch.pl:
WARNING: space prohibited between function name and open parenthesis '('
> + case UCLASS_MMC: {
> + struct efi_device_path_sd_mmc_path *sddp =
> + dp_fill(buf, dev->parent);
> + struct mmc *mmc = mmc_get_mmc_dev(dev);
> + struct blk_desc *desc = mmc_get_blk_desc(mmc);
> +
> + sddp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> + sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ?
> + DEVICE_PATH_SUB_TYPE_MSG_MMC :
> + DEVICE_PATH_SUB_TYPE_MSG_SD;
> + sddp->dp.length = sizeof(*sddp);
> + sddp->slot_number = 0; // XXX ???
> +
> + return &sddp[1];
> + }
> +#endif
> + case UCLASS_MASS_STORAGE:
> + case UCLASS_USB_HUB: {
> + struct efi_device_path_usb_class *udp =
> + dp_fill(buf, dev->parent);
> + struct usb_device *udev = dev_get_parent_priv(dev);
> + struct usb_device_descriptor *desc = &udev->descriptor;
> +
> + udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> + udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS;
> + udp->dp.length = sizeof(*udp);
> + udp->vendor_id = desc->idVendor;
> + udp->product_id = desc->idProduct;
> + udp->device_class = desc->bDeviceClass;
> + udp->device_subclass = desc->bDeviceSubClass;
> + udp->device_protocol = desc->bDeviceProtocol;
> +
> + return &udp[1];
> + }
> + default:
> + debug("unhandled device class: %s (%u)\n",
> + dev->name, dev->driver->id);
scripts/checkpatch.pl:
Alignment should match open parenthesis
> + return dp_fill(buf, dev->parent);
> + }
> +}
> +
> +/* Construct a device-path from a device: */
> +struct efi_device_path *efi_dp_from_dev(struct udevice *dev)
> +{
> + void *buf, *start;
> +
> + start = buf = calloc(1, dp_size(dev) + sizeof(END));
> + buf = dp_fill(buf, dev);
> + *((struct efi_device_path *)buf) = END;
> +
> + return start;
> +}
> +#endif
> +
> +static unsigned dp_part_size(struct blk_desc *desc, int part)
> +{
> + unsigned dpsize;
> +
> +#ifdef CONFIG_BLK
> + dpsize = dp_size(desc->bdev->parent);
> +#else
> + dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb);
> +#endif
> +
> + if (part == 0) /* the actual disk, not a partition */
> + return dpsize;
> +
> + if (desc->part_type == PART_TYPE_ISO) {
> + dpsize += sizeof(struct efi_device_path_cdrom_path);
> + } else {
> + dpsize += sizeof(struct efi_device_path_hard_drive_path);
> + }
Please, have a look at all warnings produced by
scripts/checkpatch.pl. Here you get:
WARNING: braces {} are not necessary for any arm of this statement
#464: FILE: lib/efi_loader/efi_device_path.c:289:
+ if (desc->part_type == PART_TYPE_ISO) {
[...]
+ } else {
[...]
Best regards
Heinrich
> +
> + return dpsize;
> +}
> +
> +static void *dp_part_fill(void *buf, struct blk_desc *desc, int part)
> +{
> + disk_partition_t info;
> +
> +#ifdef CONFIG_BLK
> + buf = dp_fill(buf, desc->bdev->parent);
> +#else
> + /*
> + * We *could* make a more accurate path, by looking at if_type
> + * and handling all the different cases like we do for non-
> + * legacy (ie CONFIG_BLK=y) case. But most important thing
> + * is just to have a unique device-path for if_type+devnum.
> + * So map things to a fictional USB device:
> + */
> + struct efi_device_path_usb *udp;
> +
> + memcpy(buf, &ROOT, sizeof(ROOT));
> + buf += sizeof(ROOT);
> +
> + udp = buf;
> + udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> + udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB;
> + udp->dp.length = sizeof(*udp);
> + udp->parent_port_number = desc->if_type;
> + udp->usb_interface = desc->devnum;
> + buf = &udp[1];
> +#endif
> +
> + if (part == 0) /* the actual disk, not a partition */
> + return buf;
> +
> + part_get_info(desc, part, &info);
> +
> + if (desc->part_type == PART_TYPE_ISO) {
> + struct efi_device_path_cdrom_path *cddp = buf;
> +
> + cddp->boot_entry = part - 1;
> + cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
> + cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH;
> + cddp->dp.length = sizeof (*cddp);
> + cddp->partition_start = info.start;
> + cddp->partition_end = info.size;
> +
> + buf = &cddp[1];
> + } else {
> + struct efi_device_path_hard_drive_path *hddp = buf;
> +
> + hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
> + hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH;
> + hddp->dp.length = sizeof (*hddp);
> + hddp->partition_number = part - 1;
> + hddp->partition_start = info.start;
> + hddp->partition_end = info.size;
> + if (desc->part_type == PART_TYPE_EFI)
> + hddp->partmap_type = 2;
> + else
> + hddp->partmap_type = 1;
> + hddp->signature_type = desc->sig_type;
> + if (hddp->signature_type != 0)
> + memcpy(hddp->partition_signature, &desc->guid_sig,
> + sizeof(hddp->partition_signature));
> +
> + buf = &hddp[1];
> + }
> +
> + return buf;
> +}
> +
> +
> +/* Construct a device-path from a partition on a blk device: */
> +struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part)
> +{
> + void *buf, *start;
> +
> + start = buf = calloc(1, dp_part_size(desc, part) + sizeof(END));
> +
> + buf = dp_part_fill(buf, desc, part);
> +
> + *((struct efi_device_path *)buf) = END;
> +
> + return start;
> +}
> +
> +/* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */
> +static void path_to_uefi(u16 *uefi, const char *path)
> +{
> + while (*path) {
> + char c = *(path++);
> + if (c == '/')
> + c = '\\';
> + *(uefi++) = c;
> + }
> + *uefi = '\0';
> +}
> +
> +/*
> + * If desc is NULL, this creates a path with only the file component,
> + * otherwise it creates a full path with both device and file components
> + */
> +struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
> + const char *path)
> +{
> + struct efi_device_path_file_path *fp;
> + void *buf, *start;
> + unsigned dpsize = 0, fpsize;
> +
> + if (desc)
> + dpsize = dp_part_size(desc, part);
> +
> + // TODO efi_device_path_file_path should be variable length:
> + fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1);
> + dpsize += fpsize;
> +
> + start = buf = calloc(1, dpsize + sizeof(END));
> +
> + if (desc)
> + buf = dp_part_fill(buf, desc, part);
> +
> + /* add file-path: */
> + fp = buf;
> + fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
> + fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
> + fp->dp.length = fpsize;
> + path_to_uefi(fp->str, path);
> + buf += fpsize;
> +
> + *((struct efi_device_path *)buf) = END;
> +
> + return start;
> +}
> +
> +#ifdef CONFIG_NET
> +struct efi_device_path *efi_dp_from_eth(void)
> +{
> + struct efi_device_path_mac_addr *ndp;
> + void *buf, *start;
> + unsigned dpsize = 0;
> +
> + assert(eth_get_dev());
> +
> +#ifdef CONFIG_DM_ETH
> + dpsize += dp_size(eth_get_dev());
> +#else
> + dpsize += sizeof(ROOT);
> +#endif
> + dpsize += sizeof(*ndp);
> +
> + start = buf = calloc(1, dpsize + sizeof(END));
> +
> +#ifdef CONFIG_DM_ETH
> + buf = dp_fill(buf, eth_get_dev());
> +#else
> + memcpy(buf, &ROOT, sizeof(ROOT));
> + buf += sizeof(ROOT);
> +#endif
> +
> + ndp = buf;
> + ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE;
> + ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR;
> + ndp->dp.length = sizeof(*ndp);
> + memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN);
> + buf = &ndp[1];
> +
> + *((struct efi_device_path *)buf) = END;
> +
> + return start;
> +}
> +#endif
> +
> +/*
> + * Helper to split a full device path (containing both device and file
> + * parts) into it's constituent parts.
> + */
> +void efi_dp_split_file_path(struct efi_device_path *full_path,
> + struct efi_device_path **device_path,
> + struct efi_device_path **file_path)
> +{
> + struct efi_device_path *p, *dp, *fp;
> +
> + dp = efi_dp_dup(full_path);
> + p = dp;
> + while (!EFI_DP_TYPE(p, MEDIA_DEVICE, FILE_PATH))
> + p = efi_dp_next(p);
> + fp = efi_dp_dup(p);
> +
> + p->type = DEVICE_PATH_TYPE_END;
> + p->sub_type = DEVICE_PATH_SUB_TYPE_END;
> + p->length = sizeof(*p);
> +
> + *device_path = dp;
> + *file_path = fp;
> +}
>
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