[PATCH v5 04/28] efi: Locate all block devices in the app
Heinrich Schuchardt
xypron.glpk at gmx.de
Sat Dec 4 19:43:57 CET 2021
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 */
> + return 0;
> +
> + efi_guid_t efi_disk_guid = EFI_DISK_IO_PROTOCOL_GUID;
> + 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 (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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