diff options
Diffstat (limited to 'lib/efi_loader/efi_device_path.c')
| -rw-r--r-- | lib/efi_loader/efi_device_path.c | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c new file mode 100644 index 0000000000..5d5c3b3464 --- /dev/null +++ b/lib/efi_loader/efi_device_path.c @@ -0,0 +1,563 @@ +/* + * 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> + +/* 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: */ +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, +}; + +static void *dp_alloc(size_t sz) +{ + void *buf; + + if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) != EFI_SUCCESS) + return NULL; + + return buf; +} + +/* + * Iterate to next block in device-path, terminating (returning NULL) + * at /End* node. + */ +struct efi_device_path *efi_dp_next(const struct efi_device_path *dp) +{ + if (dp == NULL) + return NULL; + if (dp->type == DEVICE_PATH_TYPE_END) + return NULL; + dp = ((void *)dp) + dp->length; + if (dp->type == DEVICE_PATH_TYPE_END) + return NULL; + return (struct efi_device_path *)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_device_path **rem) +{ + 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) { + if (rem) { + *rem = ((void *)dp) + + efi_dp_size(obj_dp); + } + return efiobj; + } + + obj_dp = shorten_path(efi_dp_next(obj_dp)); + } while (short_path && obj_dp); + } + } + + return NULL; +} + + +/* + * Find an efiobj from device-path, if 'rem' is not NULL, returns the + * remaining part of the device path after the matched object. + */ +struct efi_object *efi_dp_find_obj(struct efi_device_path *dp, + struct efi_device_path **rem) +{ + struct efi_object *efiobj; + + efiobj = find_obj(dp, false, rem); + + if (!efiobj) + efiobj = find_obj(dp, true, rem); + + return efiobj; +} + +/* return size not including End node: */ +unsigned efi_dp_size(const 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(const struct efi_device_path *dp) +{ + struct efi_device_path *ndp; + unsigned sz = efi_dp_size(dp) + sizeof(END); + + if (!dp) + return NULL; + + ndp = dp_alloc(sz); + memcpy(ndp, dp, sz); + + return ndp; +} + +struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1, + const struct efi_device_path *dp2) +{ + struct efi_device_path *ret; + + if (!dp1) { + ret = efi_dp_dup(dp2); + } else if (!dp2) { + ret = efi_dp_dup(dp1); + } else { + /* both dp1 and dp2 are non-null */ + unsigned sz1 = efi_dp_size(dp1); + unsigned sz2 = efi_dp_size(dp2); + void *p = dp_alloc(sz1 + sz2 + sizeof(END)); + memcpy(p, dp1, sz1); + memcpy(p + sz1, dp2, sz2); + memcpy(p + sz1 + sz2, &END, sizeof(END)); + ret = p; + } + + return ret; +} + +struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp, + const struct efi_device_path *node) +{ + struct efi_device_path *ret; + + if (!node && !dp) { + ret = efi_dp_dup(&END); + } else if (!node) { + ret = efi_dp_dup(dp); + } else if (!dp) { + unsigned sz = node->length; + void *p = dp_alloc(sz + sizeof(END)); + memcpy(p, node, sz); + memcpy(p + sz, &END, sizeof(END)); + ret = p; + } else { + /* both dp and node are non-null */ + unsigned sz = efi_dp_size(dp); + void *p = dp_alloc(sz + node->length + sizeof(END)); + memcpy(p, dp, sz); + memcpy(p + sz, node, node->length); + memcpy(p + sz + node->length, &END, sizeof(END)); + ret = p; + } + + return ret; +} + +#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); + 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) + 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 = dev->seq; + + 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); + 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 = dp_alloc(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); + + 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 = dp_alloc(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); + + fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1); + dpsize += fpsize; + + start = buf = dp_alloc(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 = dp_alloc(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; +} |