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@gmail.com> Signed-off-by: Alexander Graf <agraf@suse.de>master
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/*
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* EFI device path from u-boot device-model mapping |
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* |
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* (C) Copyright 2017 Rob Clark |
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* |
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* SPDX-License-Identifier: GPL-2.0+ |
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*/ |
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#include <common.h> |
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#include <blk.h> |
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#include <dm.h> |
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#include <usb.h> |
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#include <mmc.h> |
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#include <efi_loader.h> |
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#include <inttypes.h> |
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#include <part.h> |
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/* template END node: */ |
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static const struct efi_device_path END = { |
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.type = DEVICE_PATH_TYPE_END, |
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.sub_type = DEVICE_PATH_SUB_TYPE_END, |
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.length = sizeof(END), |
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}; |
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#define U_BOOT_GUID \ |
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EFI_GUID(0xe61d73b9, 0xa384, 0x4acc, \
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0xae, 0xab, 0x82, 0xe8, 0x28, 0xf3, 0x62, 0x8b) |
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/* template ROOT node: */ |
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static const struct efi_device_path_vendor ROOT = { |
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.dp = { |
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.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE, |
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.sub_type = DEVICE_PATH_SUB_TYPE_VENDOR, |
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.length = sizeof(ROOT), |
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}, |
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.guid = U_BOOT_GUID, |
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}; |
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static void *dp_alloc(size_t sz) |
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{ |
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void *buf; |
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if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) != EFI_SUCCESS) |
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return NULL; |
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return buf; |
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} |
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/*
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* Iterate to next block in device-path, terminating (returning NULL) |
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* at /End* node. |
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*/ |
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struct efi_device_path *efi_dp_next(const struct efi_device_path *dp) |
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{ |
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if (dp == NULL) |
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return NULL; |
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if (dp->type == DEVICE_PATH_TYPE_END) |
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return NULL; |
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dp = ((void *)dp) + dp->length; |
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if (dp->type == DEVICE_PATH_TYPE_END) |
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return NULL; |
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return (struct efi_device_path *)dp; |
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} |
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/*
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* Compare two device-paths, stopping when the shorter of the two hits |
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* an End* node. This is useful to, for example, compare a device-path |
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* representing a device with one representing a file on the device, or |
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* a device with a parent device. |
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*/ |
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int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b) |
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{ |
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while (1) { |
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int ret; |
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ret = memcmp(&a->length, &b->length, sizeof(a->length)); |
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if (ret) |
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return ret; |
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ret = memcmp(a, b, a->length); |
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if (ret) |
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return ret; |
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a = efi_dp_next(a); |
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b = efi_dp_next(b); |
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if (!a || !b) |
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return 0; |
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} |
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} |
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/*
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* See UEFI spec (section 3.1.2, about short-form device-paths.. |
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* tl;dr: we can have a device-path that starts with a USB WWID |
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* or USB Class node, and a few other cases which don't encode |
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* the full device path with bus hierarchy: |
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* |
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* - MESSAGING:USB_WWID |
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* - MESSAGING:USB_CLASS |
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* - MEDIA:FILE_PATH |
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* - MEDIA:HARD_DRIVE |
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* - MESSAGING:URI |
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*/ |
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static struct efi_device_path *shorten_path(struct efi_device_path *dp) |
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{ |
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while (dp) { |
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/*
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* TODO: Add MESSAGING:USB_WWID and MESSAGING:URI.. |
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* in practice fallback.efi just uses MEDIA:HARD_DRIVE |
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* so not sure when we would see these other cases. |
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*/ |
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if (EFI_DP_TYPE(dp, MESSAGING_DEVICE, MSG_USB_CLASS) || |
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EFI_DP_TYPE(dp, MEDIA_DEVICE, HARD_DRIVE_PATH) || |
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EFI_DP_TYPE(dp, MEDIA_DEVICE, FILE_PATH)) |
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return dp; |
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dp = efi_dp_next(dp); |
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} |
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return dp; |
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} |
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static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path, |
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struct efi_device_path **rem) |
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{ |
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struct efi_object *efiobj; |
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list_for_each_entry(efiobj, &efi_obj_list, link) { |
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int i; |
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for (i = 0; i < ARRAY_SIZE(efiobj->protocols); i++) { |
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struct efi_handler *handler = &efiobj->protocols[i]; |
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struct efi_device_path *obj_dp; |
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if (!handler->guid) |
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break; |
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if (guidcmp(handler->guid, &efi_guid_device_path)) |
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continue; |
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obj_dp = handler->protocol_interface; |
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do { |
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if (efi_dp_match(dp, obj_dp) == 0) { |
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if (rem) { |
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*rem = ((void *)dp) + |
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efi_dp_size(obj_dp); |
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} |
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return efiobj; |
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} |
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obj_dp = shorten_path(efi_dp_next(obj_dp)); |
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} while (short_path && obj_dp); |
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} |
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} |
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return NULL; |
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} |
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/*
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* Find an efiobj from device-path, if 'rem' is not NULL, returns the |
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* remaining part of the device path after the matched object. |
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*/ |
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struct efi_object *efi_dp_find_obj(struct efi_device_path *dp, |
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struct efi_device_path **rem) |
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{ |
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struct efi_object *efiobj; |
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efiobj = find_obj(dp, false, rem); |
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if (!efiobj) |
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efiobj = find_obj(dp, true, rem); |
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return efiobj; |
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} |
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/* return size not including End node: */ |
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unsigned efi_dp_size(const struct efi_device_path *dp) |
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{ |
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unsigned sz = 0; |
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while (dp) { |
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sz += dp->length; |
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dp = efi_dp_next(dp); |
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} |
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return sz; |
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} |
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struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp) |
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{ |
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struct efi_device_path *ndp; |
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unsigned sz = efi_dp_size(dp) + sizeof(END); |
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if (!dp) |
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return NULL; |
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ndp = dp_alloc(sz); |
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memcpy(ndp, dp, sz); |
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return ndp; |
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} |
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struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1, |
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const struct efi_device_path *dp2) |
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{ |
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struct efi_device_path *ret; |
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if (!dp1) { |
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ret = efi_dp_dup(dp2); |
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} else if (!dp2) { |
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ret = efi_dp_dup(dp1); |
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} else { |
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/* both dp1 and dp2 are non-null */ |
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unsigned sz1 = efi_dp_size(dp1); |
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unsigned sz2 = efi_dp_size(dp2); |
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void *p = dp_alloc(sz1 + sz2 + sizeof(END)); |
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memcpy(p, dp1, sz1); |
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memcpy(p + sz1, dp2, sz2); |
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memcpy(p + sz1 + sz2, &END, sizeof(END)); |
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ret = p; |
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} |
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return ret; |
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} |
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struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp, |
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const struct efi_device_path *node) |
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{ |
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struct efi_device_path *ret; |
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if (!node && !dp) { |
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ret = efi_dp_dup(&END); |
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} else if (!node) { |
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ret = efi_dp_dup(dp); |
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} else if (!dp) { |
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unsigned sz = node->length; |
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void *p = dp_alloc(sz + sizeof(END)); |
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memcpy(p, node, sz); |
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memcpy(p + sz, &END, sizeof(END)); |
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ret = p; |
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} else { |
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/* both dp and node are non-null */ |
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unsigned sz = efi_dp_size(dp); |
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void *p = dp_alloc(sz + node->length + sizeof(END)); |
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memcpy(p, dp, sz); |
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memcpy(p + sz, node, node->length); |
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memcpy(p + sz + node->length, &END, sizeof(END)); |
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ret = p; |
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} |
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return ret; |
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} |
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#ifdef CONFIG_DM |
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/* size of device-path not including END node for device and all parents
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* up to the root device. |
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*/ |
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static unsigned dp_size(struct udevice *dev) |
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{ |
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if (!dev || !dev->driver) |
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return sizeof(ROOT); |
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switch (dev->driver->id) { |
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case UCLASS_ROOT: |
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case UCLASS_SIMPLE_BUS: |
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/* stop traversing parents at this point: */ |
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return sizeof(ROOT); |
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case UCLASS_MMC: |
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return dp_size(dev->parent) + |
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sizeof(struct efi_device_path_sd_mmc_path); |
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case UCLASS_MASS_STORAGE: |
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case UCLASS_USB_HUB: |
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return dp_size(dev->parent) + |
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sizeof(struct efi_device_path_usb_class); |
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default: |
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/* just skip over unknown classes: */ |
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return dp_size(dev->parent); |
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} |
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} |
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static void *dp_fill(void *buf, struct udevice *dev) |
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{ |
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if (!dev || !dev->driver) |
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return buf; |
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switch (dev->driver->id) { |
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case UCLASS_ROOT: |
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case UCLASS_SIMPLE_BUS: { |
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/* stop traversing parents at this point: */ |
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struct efi_device_path_vendor *vdp = buf; |
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*vdp = ROOT; |
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return &vdp[1]; |
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} |
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#if defined(CONFIG_DM_MMC) && defined(CONFIG_MMC) |
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case UCLASS_MMC: { |
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struct efi_device_path_sd_mmc_path *sddp = |
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dp_fill(buf, dev->parent); |
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struct mmc *mmc = mmc_get_mmc_dev(dev); |
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struct blk_desc *desc = mmc_get_blk_desc(mmc); |
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sddp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE; |
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sddp->dp.sub_type = (desc->if_type == IF_TYPE_MMC) ? |
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DEVICE_PATH_SUB_TYPE_MSG_MMC : |
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DEVICE_PATH_SUB_TYPE_MSG_SD; |
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sddp->dp.length = sizeof(*sddp); |
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sddp->slot_number = dev->seq; |
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return &sddp[1]; |
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} |
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#endif |
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case UCLASS_MASS_STORAGE: |
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case UCLASS_USB_HUB: { |
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struct efi_device_path_usb_class *udp = |
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dp_fill(buf, dev->parent); |
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struct usb_device *udev = dev_get_parent_priv(dev); |
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struct usb_device_descriptor *desc = &udev->descriptor; |
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udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE; |
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udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB_CLASS; |
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udp->dp.length = sizeof(*udp); |
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udp->vendor_id = desc->idVendor; |
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udp->product_id = desc->idProduct; |
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udp->device_class = desc->bDeviceClass; |
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udp->device_subclass = desc->bDeviceSubClass; |
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udp->device_protocol = desc->bDeviceProtocol; |
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return &udp[1]; |
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} |
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default: |
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debug("unhandled device class: %s (%u)\n", |
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dev->name, dev->driver->id); |
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return dp_fill(buf, dev->parent); |
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} |
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} |
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/* Construct a device-path from a device: */ |
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struct efi_device_path *efi_dp_from_dev(struct udevice *dev) |
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{ |
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void *buf, *start; |
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start = buf = dp_alloc(dp_size(dev) + sizeof(END)); |
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buf = dp_fill(buf, dev); |
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*((struct efi_device_path *)buf) = END; |
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return start; |
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} |
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#endif |
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static unsigned dp_part_size(struct blk_desc *desc, int part) |
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{ |
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unsigned dpsize; |
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#ifdef CONFIG_BLK |
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dpsize = dp_size(desc->bdev->parent); |
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#else |
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dpsize = sizeof(ROOT) + sizeof(struct efi_device_path_usb); |
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#endif |
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if (part == 0) /* the actual disk, not a partition */ |
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return dpsize; |
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if (desc->part_type == PART_TYPE_ISO) |
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dpsize += sizeof(struct efi_device_path_cdrom_path); |
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else |
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dpsize += sizeof(struct efi_device_path_hard_drive_path); |
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return dpsize; |
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} |
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static void *dp_part_fill(void *buf, struct blk_desc *desc, int part) |
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{ |
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disk_partition_t info; |
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#ifdef CONFIG_BLK |
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buf = dp_fill(buf, desc->bdev->parent); |
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#else |
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/*
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* We *could* make a more accurate path, by looking at if_type |
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* and handling all the different cases like we do for non- |
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* legacy (ie CONFIG_BLK=y) case. But most important thing |
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* is just to have a unique device-path for if_type+devnum. |
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* So map things to a fictional USB device: |
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*/ |
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struct efi_device_path_usb *udp; |
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memcpy(buf, &ROOT, sizeof(ROOT)); |
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buf += sizeof(ROOT); |
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udp = buf; |
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udp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE; |
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udp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_USB; |
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udp->dp.length = sizeof(*udp); |
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udp->parent_port_number = desc->if_type; |
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udp->usb_interface = desc->devnum; |
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buf = &udp[1]; |
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#endif |
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if (part == 0) /* the actual disk, not a partition */ |
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return buf; |
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part_get_info(desc, part, &info); |
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if (desc->part_type == PART_TYPE_ISO) { |
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struct efi_device_path_cdrom_path *cddp = buf; |
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cddp->boot_entry = part - 1; |
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cddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE; |
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cddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_CDROM_PATH; |
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cddp->dp.length = sizeof(*cddp); |
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cddp->partition_start = info.start; |
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cddp->partition_end = info.size; |
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buf = &cddp[1]; |
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} else { |
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struct efi_device_path_hard_drive_path *hddp = buf; |
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hddp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE; |
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hddp->dp.sub_type = DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH; |
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hddp->dp.length = sizeof(*hddp); |
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hddp->partition_number = part - 1; |
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hddp->partition_start = info.start; |
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hddp->partition_end = info.size; |
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if (desc->part_type == PART_TYPE_EFI) |
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hddp->partmap_type = 2; |
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else |
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hddp->partmap_type = 1; |
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hddp->signature_type = desc->sig_type; |
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if (hddp->signature_type != 0) |
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memcpy(hddp->partition_signature, &desc->guid_sig, |
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sizeof(hddp->partition_signature)); |
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buf = &hddp[1]; |
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} |
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return buf; |
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} |
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/* Construct a device-path from a partition on a blk device: */ |
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struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part) |
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{ |
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void *buf, *start; |
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start = buf = dp_alloc(dp_part_size(desc, part) + sizeof(END)); |
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buf = dp_part_fill(buf, desc, part); |
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*((struct efi_device_path *)buf) = END; |
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return start; |
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} |
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/* convert path to an UEFI style path (ie. DOS style backslashes and utf16) */ |
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static void path_to_uefi(u16 *uefi, const char *path) |
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{ |
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while (*path) { |
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char c = *(path++); |
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if (c == '/') |
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c = '\\'; |
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*(uefi++) = c; |
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} |
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*uefi = '\0'; |
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} |
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/*
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* If desc is NULL, this creates a path with only the file component, |
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* otherwise it creates a full path with both device and file components |
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*/ |
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struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part, |
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const char *path) |
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{ |
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struct efi_device_path_file_path *fp; |
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void *buf, *start; |
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unsigned dpsize = 0, fpsize; |
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if (desc) |
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dpsize = dp_part_size(desc, part); |
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fpsize = sizeof(struct efi_device_path) + 2 * (strlen(path) + 1); |
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dpsize += fpsize; |
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start = buf = dp_alloc(dpsize + sizeof(END)); |
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if (desc) |
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buf = dp_part_fill(buf, desc, part); |
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/* add file-path: */ |
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fp = buf; |
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fp->dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE; |
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fp->dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH; |
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fp->dp.length = fpsize; |
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path_to_uefi(fp->str, path); |
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buf += fpsize; |
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*((struct efi_device_path *)buf) = END; |
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return start; |
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} |
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#ifdef CONFIG_NET |
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struct efi_device_path *efi_dp_from_eth(void) |
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{ |
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struct efi_device_path_mac_addr *ndp; |
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void *buf, *start; |
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unsigned dpsize = 0; |
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assert(eth_get_dev()); |
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#ifdef CONFIG_DM_ETH |
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dpsize += dp_size(eth_get_dev()); |
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#else |
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dpsize += sizeof(ROOT); |
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#endif |
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dpsize += sizeof(*ndp); |
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start = buf = dp_alloc(dpsize + sizeof(END)); |
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#ifdef CONFIG_DM_ETH |
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buf = dp_fill(buf, eth_get_dev()); |
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#else |
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memcpy(buf, &ROOT, sizeof(ROOT)); |
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buf += sizeof(ROOT); |
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#endif |
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ndp = buf; |
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ndp->dp.type = DEVICE_PATH_TYPE_MESSAGING_DEVICE; |
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ndp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MSG_MAC_ADDR; |
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ndp->dp.length = sizeof(*ndp); |
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memcpy(ndp->mac.addr, eth_get_ethaddr(), ARP_HLEN); |
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buf = &ndp[1]; |
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*((struct efi_device_path *)buf) = END; |
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return start; |
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} |
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#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; |
||||
} |
Loading…
Reference in new issue