[PATCH v5 04/28] efi: Locate all block devices in the app
Heinrich Schuchardt
xypron.glpk at gmx.de
Thu Dec 9 20:23:31 CET 2021
On 12/4/21 10:43, Heinrich Schuchardt wrote:
> On 12/4/21 16:56, Simon Glass wrote:
>> When starting the app, locate all block devices and make them available
>> to U-Boot. This allows listing partitions and accessing files in
>> filesystems.
>>
>> EFI also has the concept of 'disks', meaning boot media. For now, this
>> is not obviously useful in U-Boot, but add code to at least locate these.
>> This can be expanded later as needed.
>>
>> Series-changes; 2
>> - Store device path in struct efi_media_plat
>> - Don't export efi_bind_block()
>> - Only bind devices for media devices, not for partitions
>> - Show devices that are processed
>> - Update documentation
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>
>> (no changes since v1)
>>
>> doc/develop/uefi/u-boot_on_efi.rst | 4 +-
>> include/efi.h | 6 +-
>> include/efi_api.h | 15 ++
>> lib/efi/efi_app.c | 223 +++++++++++++++++++++++++++++
>> 4 files changed, 243 insertions(+), 5 deletions(-)
>>
>> diff --git a/doc/develop/uefi/u-boot_on_efi.rst
>> b/doc/develop/uefi/u-boot_on_efi.rst
>> index 5f2f850f071..8f81b799072 100644
>> --- a/doc/develop/uefi/u-boot_on_efi.rst
>> +++ b/doc/develop/uefi/u-boot_on_efi.rst
>> @@ -265,9 +265,7 @@ This work could be extended in a number of ways:
>>
>> - Figure out how to solve the interrupt problem
>>
>> -- Add more drivers to the application side (e.g. block devices, USB,
>> - environment access). This would mostly be an academic exercise as a
>> strong
>> - use case is not readily apparent, but it might be fun.
>> +- Add more drivers to the application side (e.g.USB, environment
>> access).
>>
>> - Avoid turning off boot services in the stub. Instead allow U-Boot
>> to make
>> use of boot services in case it wants to. It is unclear what it
>> might want
>> diff --git a/include/efi.h b/include/efi.h
>> index 0ec5913ddd1..908c5dc6ebd 100644
>> --- a/include/efi.h
>> +++ b/include/efi.h
>> @@ -419,10 +419,12 @@ struct efi_priv {
>> *
>> * @handle: handle of the controller on which this driver is installed
>> * @blkio: block io protocol proxied by this driver
>> + * @device_path: EFI path to the device
>> */
>> struct efi_media_plat {
>> - efi_handle_t handle;
>> - struct efi_block_io *blkio;
>> + efi_handle_t handle;
>> + struct efi_block_io *blkio;
>> + struct efi_device_path *device_path;
>> };
>>
>> /* Base address of the EFI image */
>> diff --git a/include/efi_api.h b/include/efi_api.h
>> index 80109f012bc..ec9fa89a935 100644
>> --- a/include/efi_api.h
>> +++ b/include/efi_api.h
>> @@ -2035,4 +2035,19 @@ struct efi_firmware_management_protocol {
>> const u16 *package_version_name);
>> };
>>
>> +#define EFI_DISK_IO_PROTOCOL_GUID \
>> + EFI_GUID(0xce345171, 0xba0b, 0x11d2, 0x8e, 0x4f, \
>> + 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
>> +
>> +struct efi_disk {
>> + u64 revision;
>> + efi_status_t (EFIAPI *read_disk)(struct efi_disk *this, u32
>> media_id,
>> + u64 offset, efi_uintn_t buffer_size,
>> + void *buffer);
>> +
>> + efi_status_t (EFIAPI *write_disk)(struct efi_disk *this, u32
>> media_id,
>> + u64 offset, efi_uintn_t buffer_size,
>> + void *buffer);
>> +};
>> +
>> #endif
>> diff --git a/lib/efi/efi_app.c b/lib/efi/efi_app.c
>> index f61665686c5..e38d46b15db 100644
>> --- a/lib/efi/efi_app.c
>> +++ b/lib/efi/efi_app.c
>> @@ -21,6 +21,9 @@
>> #include <efi.h>
>> #include <efi_api.h>
>> #include <sysreset.h>
>> +#include <dm/device-internal.h>
>> +#include <dm/lists.h>
>> +#include <dm/root.h>
>>
>> DECLARE_GLOBAL_DATA_PTR;
>>
>> @@ -46,6 +49,64 @@ int efi_info_get(enum efi_entry_t type, void
>> **datap, int *sizep)
>> return -ENOSYS;
>> }
>>
>> +/**
>> + * efi_print_str() - Print a UFT-16 string to the U-Boot console
>> + *
>> + * @str: String to print
>> + */
>> +static void efi_print_str(const u16 *str)
>> +{
>> + while (*str) {
>> + int ch = *str++;
>> +
>> + if (ch > ' ' && ch < 127)
>> + putc(ch);
>> + }
>> +}
>> +
>> +/**
>> + * efi_bind_block() - bind a new block device to an EFI device
>> + *
>> + * Binds a new top-level EFI_MEDIA device as well as a child block
>> device so
>> + * that the block device can be accessed in U-Boot.
>> + *
>> + * The device can then be accessed using 'part list efi 0', 'fat ls
>> efi 0:1',
>> + * for example, just like any other interface type.
>> + *
>> + * @handle: handle of the controller on which this driver is installed
>> + * @blkio: block io protocol proxied by this driver
>> + * @device_path: EFI device path structure for this
>> + * @len: Length of @device_path in bytes
>> + * @devp: Returns the bound device
>> + * @return 0 if OK, -ve on error
>> + */
>> +int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio,
>> + struct efi_device_path *device_path, int len,
>> + struct udevice **devp)
>> +{
>> + struct efi_media_plat plat;
>> + struct udevice *dev;
>> + char name[18];
>> + int ret;
>> +
>> + plat.handle = handle;
>> + plat.blkio = blkio;
>> + plat.device_path = malloc(device_path->length);
>> + if (!plat.device_path)
>> + return log_msg_ret("path", -ENOMEM);
>> + memcpy(plat.device_path, device_path, device_path->length);
>> + ret = device_bind(dm_root(), DM_DRIVER_GET(efi_media), "efi_media",
>> + &plat, ofnode_null(), &dev);
>> + if (ret)
>> + return log_msg_ret("bind", ret);
>> +
>> + snprintf(name, sizeof(name), "efi_media_%x", dev_seq(dev));
>> + device_set_name(dev, name);
>> + *devp = dev;
>> +
>> + return 0;
>> +}
>> +
>> static efi_status_t setup_memory(struct efi_priv *priv)
>> {
>> struct efi_boot_services *boot = priv->boot;
>> @@ -105,6 +166,168 @@ static void free_memory(struct efi_priv *priv)
>> global_data_ptr = NULL;
>> }
>>
>
>
> Missing function description
>
>
>> +static int setup_disks(void)
>> +{
>> + /* This is not fully implemented yet */
see hint below.
>> + return 0;
>> +
>> + efi_guid_t efi_disk_guid = EFI_DISK_IO_PROTOCOL_GUID;
U-Boot does not implement the EFI_DISK_IO_PROTOCOL. So you will not be
able to run U-Boot as an EFI app loaded by U-Boot which might be nice
for testing.
The more basic protocol is the EFI_BLOCK_IO_PROTOCOL. The difference is
that the EFI_BLOCK_IO_PROTOCOL requires using a properly aligned buffer.
>> + struct efi_boot_services *boot = efi_get_boot();
>> + struct efi_disk *disk;
>> + int ret;
>> +
>> + if (!boot)
>> + return log_msg_ret("sys", -ENOSYS);
>> + ret = boot->locate_protocol(&efi_disk_guid, NULL, (void **)&disk);
If you want to find all handles implementing a protocol, you can use
EFI_BOOT_SERVICES.LocateHandleBuffer() with SearchType ByProtocol.
I guess we should add this patch to U-Boot once it is completed.
Best regards
Heinrich
>> + if (ret)
>> + return log_msg_ret("prot", -ENOTSUPP);
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * devpath_is_partition() - Figure out if a device path is a partition
>> + *
>> + * Checks if a device path refers to a partition on some media
>> device. This
>> + * works by checking for a valid partition number in a hard-driver
>> media device
>> + * as the final component of the device path.
>> + *
>> + * @return true if a partition, false if not (e.g. it might be media
>> which
>> + * contains partitions)
>
> Please, stick to the format for function descriptions defined in
> https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation
>
>
> The description for parameter @path: is missing.
> @return does not exist. Please, use Return:.
>
>
>> + */
>> +static bool devpath_is_partition(const struct efi_device_path *path)
>> +{
>> + const struct efi_device_path *p;
>> + bool was_part;
>> +
>> + for (p = path; p->type != DEVICE_PATH_TYPE_END;
>> + p = (void *)p + p->length) {
>> + was_part = false;
>> + if (p->type == DEVICE_PATH_TYPE_MEDIA_DEVICE &&
>> + p->sub_type == DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH) {
>> + struct efi_device_path_hard_drive_path *hd =
>> + (void *)path;
>> +
>> + if (hd->partition_number)
>> + was_part = true;
>> + }
>> + }
>> +
>> + return was_part;
>> +}
>> +
>> +/**
>> + * setup_block() - Find all block devices and setup EFI devices for them
>> + *
>> + * Partitions are ignored, since U-Boot has partition handling.
>> Errors with
>> + * particular devices produce a warning but execution continues to
>> try to
>> + * find others.
>> + *
>> + * @return 0 if found, -ENOSYS if there is no boot-services table,
>> -ENOTSUPP
>> + * if a required protocol is not supported
>
> %s/@return/Return:/
>
>> + */
>> +static int setup_block(void)
>> +{
>> + efi_guid_t efi_blkio_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
>> + efi_guid_t efi_devpath_guid = EFI_DEVICE_PATH_PROTOCOL_GUID;
>> + efi_guid_t efi_pathutil_guid =
>> EFI_DEVICE_PATH_UTILITIES_PROTOCOL_GUID;
>> + efi_guid_t efi_pathtext_guid =
>> EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
>> + struct efi_boot_services *boot = efi_get_boot();
>> + struct efi_device_path_utilities_protocol *util;
>> + struct efi_device_path_to_text_protocol *text;
>> + struct efi_device_path *path;
>> + struct efi_block_io *blkio;
>> + efi_uintn_t num_handles;
>> + efi_handle_t *handle;
>> + int ret, i;
>> +
>> + if (!boot)
>> + return log_msg_ret("sys", -ENOSYS);
>> +
>> + /* Find all devices which support the block I/O protocol */
>> + ret = boot->locate_handle_buffer(BY_PROTOCOL, &efi_blkio_guid, NULL,
>> + &num_handles, &handle);
>> + if (ret)
>> + return log_msg_ret("loc", -ENOTSUPP);
>> + log_debug("Found %d handles:\n", (int)num_handles);
>> +
>> + /* We need to look up the path size and convert it to text */
>> + ret = boot->locate_protocol(&efi_pathutil_guid, NULL, (void
>> **)&util);
>> + if (ret)
>> + return log_msg_ret("util", -ENOTSUPP);
>> + ret = boot->locate_protocol(&efi_pathtext_guid, NULL, (void
>> **)&text);
>> + if (ret)
>> + return log_msg_ret("text", -ENOTSUPP);
>> +
>> + for (i = 0; i < num_handles; i++) {
>> + struct udevice *dev;
>> + const u16 *name;
>> + bool is_part;
>> + int len;
>> +
>> + ret = boot->handle_protocol(handle[i], &efi_devpath_guid,
>> + (void **)&path);
>> + if (ret) {
>> + log_warning("- devpath %d failed (ret=%d)\n", i, ret);
>> + continue;
>> + }
>> +
>> + ret = boot->handle_protocol(handle[i], &efi_blkio_guid,
>> + (void **)&blkio);
>> + if (ret) {
>> + log_warning("- blkio %d failed (ret=%d)\n", i, ret);
>> + continue;
>> + }
>> +
>> + name = text->convert_device_path_to_text(path, true, false);
>> + is_part = devpath_is_partition(path);
>> +
>> + if (!is_part) {
>> + len = util->get_device_path_size(path);
>> + ret = efi_bind_block(handle[i], blkio, path, len, &dev);
>> + if (ret) {
>> + log_warning("- blkio bind %d failed (ret=%d)\n",
>> + i, ret);
>> + continue;
>> + }
>> + } else {
>> + dev = NULL;
>> + }
>> +
>> + /*
>> + * Show the device name if we created one. Otherwise indicate
>> + * that it is a partition.
>> + *
>> + * We don't seem to have have a way to print unicode on the
>> + * U-Boot console at present, so use our own function.
>> + */
>> + printf("%2d: %-12s ", i, dev ? dev->name : "<partition>");
>> + efi_print_str(name);
>> + printf("\n");
>> + }
>> + boot->free_pool(handle);
>> +
>> + return 0;
>> +}
>> +
>
> Missing function description.
>
> Best regards
>
> Heinrich
>
>> +int dm_scan_other(bool pre_reloc_only)
>> +{
>> + if (gd->flags & GD_FLG_RELOC) {
>> + int ret;
>> +
>> + ret = setup_block();
>> + if (ret)
>> + return ret;
>> +
>> + /* Not needed at present, but could be useful one day? */
>> + ret = setup_disks();
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /**
>> * efi_main() - Start an EFI image
>> *
>>
>
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