efi_loader: add device-path utils

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>
This commit is contained in:
Rob Clark 2017-09-13 18:05:28 -04:00 committed by Alexander Graf
parent c80214ce1f
commit b66c60dde9
5 changed files with 611 additions and 3 deletions

View File

@ -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;

View File

@ -220,6 +220,32 @@ extern void *efi_bounce_buffer;
#define EFI_LOADER_BOUNCE_BUFFER_SIZE (64 * 1024 * 1024)
#endif
struct efi_device_path *efi_dp_next(const 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,
struct efi_device_path **rem);
unsigned efi_dp_size(const struct efi_device_path *dp);
struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp);
struct efi_device_path *efi_dp_append(const struct efi_device_path *dp1,
const struct efi_device_path *dp2);
struct efi_device_path *efi_dp_append_node(const struct efi_device_path *dp,
const struct efi_device_path *node);
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)
{

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@ -16,7 +16,7 @@ endif
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

View File

@ -716,8 +716,17 @@ static efi_status_t EFIAPI efi_locate_device_path(efi_guid_t *protocol,
struct efi_device_path **device_path,
efi_handle_t *device)
{
EFI_ENTRY("%p, %p, %p", protocol, device_path, device);
return EFI_EXIT(EFI_NOT_FOUND);
struct efi_object *efiobj;
EFI_ENTRY("%pUl, %p, %p", protocol, device_path, device);
efiobj = efi_dp_find_obj(*device_path, device_path);
if (!efiobj)
return EFI_EXIT(EFI_NOT_FOUND);
*device = efiobj->handle;
return EFI_EXIT(EFI_SUCCESS);
}
/* Collapses configuration table entries, removing index i */

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@ -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;
}