[PATCH 2/2] efi_loader: support boot from URI device path

Masahisa Kojima masahisa.kojima at linaro.org
Fri Aug 25 08:40:29 CEST 2023


On Thu, 24 Aug 2023 at 11:24, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
>
> Kojima-san,
>
> On Wed, Aug 23, 2023 at 05:37:20PM +0900, Masahisa Kojima wrote:
> > This supports to boot from the URI device path.
> > When user selects the URI device path, bootmgr downloads
> > the file using wget into the address specified by loadaddr
> > env variable.
> > If the file is .iso or .img file, mount the image with blkmap
> > then try to boot with the default file(e.g. EFI/BOOT/BOOTAA64.EFI).
> > If the file is .efi file, load and start the downloaded file.
>
> Is this behavior part of UEFI specification?
> Even so, it would be better to describe it in uefi.rst (or else),
> including URI usage.

Yes, I will update the documentation.

>
> > Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> > ---
> >  lib/efi_loader/efi_bootmgr.c | 213 +++++++++++++++++++++++++++++++++++
> >  1 file changed, 213 insertions(+)
> >
> > diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> > index a40762c74c..8b20f486f2 100644
> > --- a/lib/efi_loader/efi_bootmgr.c
> > +++ b/lib/efi_loader/efi_bootmgr.c
> > @@ -7,10 +7,14 @@
> >
> >  #define LOG_CATEGORY LOGC_EFI
> >
> > +#include <blk.h>
> > +#include <blkmap.h>
> >  #include <common.h>
> >  #include <charset.h>
> > +#include <dm.h>
> >  #include <log.h>
> >  #include <malloc.h>
> > +#include <net.h>
> >  #include <efi_default_filename.h>
> >  #include <efi_loader.h>
> >  #include <efi_variable.h>
> > @@ -168,6 +172,209 @@ out:
> >       return ret;
> >  }
> >
> > +#if (IS_ENABLED(CONFIG_BLKMAP) && IS_ENABLED(CONFIG_CMD_WGET) && IS_ENABLED(CONFIG_CMD_DNS))
> > +/**
> > + * mount_image() - mount the image
> > + *
> > + * @lo_label label of load option
> > + * @file_size        file size
> > + * @handle:  pointer to handle for newly installed image
> > + * Return:   status code
> > + */
> > +static efi_status_t mount_image(u16 *lo_label, int file_size,
> > +                             efi_handle_t *handle)
>
> I wonder why not adding "address" parameter to make this function
> more generic as Simon suggested.

wget and other network commands take the load address with the
image_load_address
global variable. Anyway, adding address as parameter is better.

>
> > +{
> > +     int err;
> > +     efi_status_t ret;
> > +     char *label = NULL, *p;
> > +     lbaint_t blknum;
> > +     struct udevice *bm_dev;
> > +     efi_handle_t bm_handle;
> > +     struct udevice *blk, *partition;
> > +     struct efi_handler *handler;
> > +     struct efi_device_path *file_path;
> > +     struct efi_device_path *device_path;
> > +
> > +     label = efi_alloc(utf16_utf8_strlen(lo_label) + 1);
> > +     if (!label)
> > +             return EFI_OUT_OF_RESOURCES;
> > +
> > +     p = label;
> > +     utf16_utf8_strcpy(&p, lo_label);
> > +     err = blkmap_create(label, NULL);
> > +     if (err) {
> > +             log_err("failed to create blkmap\n");
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +     bm_dev = blkmap_from_label(label);
> > +     if (!bm_dev) {
> > +             log_err("\"%s\" is not the name of any known blkmap\n", label);
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +
> > +     blknum = file_size / 512; /* TODO: don't use literal value. */
> > +     err = blkmap_map_pmem(bm_dev, 0, blknum, image_load_addr);
> > +     if (err) {
> > +             log_err("Unable to map %#llx at block %d : %d\n",
> > +                     (unsigned long long)image_load_addr, 0, err);
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +     log_info("Block %d+0x" LBAF " mapped to %#llx\n", 0, blknum,
> > +              (unsigned long long)image_load_addr);
> > +
> > +     /* TODO: without calling this, partition devices are not binded. */
> > +     blk_list_part(UCLASS_BLKMAP);
>
> I think that blkmap should provide a way to *probe* its child block
> device. In fact,
>         struct blkmap *bm = dev_get_plat(bm_dev);
>         device_probe(bm->blk);
> should work. (Not tested though)

Thank you. I implemented this initially but did not work as expected.
I will check again.

>
> > +
> > +     /*
> > +      * Search the partition having EFI_SIMPLE_FILE_SYSTEM_PROTOCOL,
> > +      * then try to load with the default boot file(e.g. EFI/BOOT/BOOTAA64.EFI).
> > +      */
> > +     device_foreach_child(blk, bm_dev)
>
> Does bm_dev have more than one block devices?

No, I can remove foreach_child.

>
> > +     {
> > +             device_foreach_child(partition, blk)
> > +             {
> > +                     if (dev_tag_get_ptr(partition, DM_TAG_EFI,
> > +                                         (void **)&bm_handle)) {
> > +                             log_warning("DM_TAG_EFI not found\n");
> > +                             continue;
> > +                     }
> > +
> > +                     ret = efi_search_protocol(
> > +                             bm_handle,
> > +                             &efi_simple_file_system_protocol_guid,
> > +                             &handler);
> > +                     if (ret != EFI_SUCCESS)
> > +                             continue;
> > +
> > +                     ret = efi_search_protocol(
> > +                             bm_handle, &efi_guid_device_path, &handler);
> > +                     if (ret != EFI_SUCCESS)
> > +                             continue;
> > +
> > +                     ret = efi_protocol_open(handler, (void **)&device_path,
> > +                                             efi_root, NULL,
> > +                                             EFI_OPEN_PROTOCOL_GET_PROTOCOL);
> > +                     if (ret != EFI_SUCCESS)
> > +                             continue;
> > +
> > +                     file_path = expand_media_path(device_path);
> > +                     ret = EFI_CALL(efi_load_image(true, efi_root, file_path,
> > +                                                   NULL, 0, handle));
> > +                     efi_free_pool(file_path);
> > +                     if (ret == EFI_SUCCESS)
> > +                             goto out;
> > +             }
> > +     }
>
> Another idea would be to create a new boot option (as a removable
> media) and to invoke it from bootmgr.
>
> > +
> > +out:
> > +     efi_free_pool(label);
> > +
> > +     return ret;
> > +}
> > +
> > +/**
> > + * try_load_from_uri_path() - Handle the URI device path
> > + *
> > + * @uridp:   uri device path
> > + * @lo_label label of load option
> > + * @handle:  pointer to handle for newly installed image
> > + * Return:   status code
> > + */
> > +static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
> > +                                        u16 *lo_label,
> > +                                        efi_handle_t *handle)
> > +{
> > +     efi_status_t ret;
> > +     int file_size, file_name_len;
> > +     char *s, *host_name, *file_name, *str_copy;
> > +
> > +     /*
> > +      * Download file using wget.
> > +      *
> > +      * URI device path content is like http://www.example.com/sample/test.iso.
> > +      * U-Boot wget takes the target uri in this format.
> > +      *  "<http server ip>:<file path>"  e.g.) 192.168.1.1:/sample/test.iso
> > +      * Need to resolve the http server ip address before starting wget.
> > +      */
> > +
> > +     /* only support "http://" */
> > +     if (strncmp(uridp->uri, "http://", 7)) {
> > +             log_err("Error: uri must start with http://\n");
> > +             return EFI_INVALID_PARAMETER;
> > +     }
> > +
> > +     str_copy = strdup(uridp->uri);
> > +     if (!str_copy)
> > +             return EFI_OUT_OF_RESOURCES;
> > +     s = str_copy + strlen("http://");
> > +     host_name = strsep(&s, "/");
> > +     if (!s) {
> > +             log_err("Error: invalied uri, no file path\n");
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +     file_name = s;
> > +     net_dns_resolve = host_name;
> > +     net_dns_env_var = "httpserverip";
> > +     if (net_loop(DNS) < 0) {
> > +             log_err("Error: dns lookup of %s failed, check setup\n", net_dns_resolve);
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +     s = env_get("httpserverip");
> > +     if (!s) {
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +
> > +     /*
> > +      * WGET requires that "net_boot_file_name" and "image_load_addr" global
> > +      * variables are properly set in advance.
> > +      */
> > +     strlcpy(net_boot_file_name, s, 1024);
> > +     strlcat(net_boot_file_name, ":/", 1024); /* append '/' which is removed by strsep() */
> > +     strlcat(net_boot_file_name, file_name, 1024);
> > +     s = env_get("loadaddr");
> > +     if (!s) {
> > +             log_err("Error: loadaddr is not set\n");
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +     image_load_addr = hextoul(s, NULL);
> > +
> > +     file_size = net_loop(WGET);
> > +     if (file_size < 0) {
> > +             log_err("Error: downloading file failed\n");
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +
> > +     /*
> > +      * Identify file type by file extension.
> > +      * If the file extension is ".iso" or ".img", mount it and boot with default file.
> > +      * If the file is ".efi", load and start the downloaded file.
> > +      */
> > +     file_name_len = strlen(net_boot_file_name);
> > +     if (!strncmp(&net_boot_file_name[file_name_len - 4], ".iso", 4) ||
> > +         !strncmp(&net_boot_file_name[file_name_len - 4], ".img", 4)) {
> > +             ret = mount_image(lo_label, file_size, handle);
> > +     } else if (!strncmp(&net_boot_file_name[file_name_len - 4], ".efi", 4)) {
> > +             ret = efi_run_image((void *)image_load_addr, file_size);
>
> Nak.
> try_load_from_uri_path() is called from try_load_entry().
> This function's purpose is solely to load an image.
> The execution should be triggered later.

Yes, you are correct.
I will fix this.

Thanks,
Masahisa Kojima

>
> -Takahiro Akashi
>
>
> > +     } else {
> > +             log_err("Error: file type is not supported\n");
> > +             ret = EFI_INVALID_PARAMETER;
> > +     }
> > +
> > +out:
> > +     free(str_copy);
> > +
> > +     return ret;
> > +}
> > +#endif
> > +
> >  /**
> >   * try_load_entry() - try to load image for boot option
> >   *
> > @@ -211,6 +418,12 @@ static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
> >               if (EFI_DP_TYPE(lo.file_path, MEDIA_DEVICE, FILE_PATH)) {
> >                       /* file_path doesn't contain a device path */
> >                       ret = try_load_from_short_path(lo.file_path, handle);
> > +#if (IS_ENABLED(CONFIG_BLKMAP) && IS_ENABLED(CONFIG_CMD_WGET) && IS_ENABLED(CONFIG_CMD_DNS))
> > +             } else if (EFI_DP_TYPE(lo.file_path, MESSAGING_DEVICE, MSG_URI)) {
> > +                     ret = try_load_from_uri_path(
> > +                             (struct efi_device_path_uri *)lo.file_path,
> > +                             lo.label, handle);
> > +#endif
> >               } else {
> >                       file_path = expand_media_path(lo.file_path);
> >                       ret = EFI_CALL(efi_load_image(true, efi_root, file_path,
> > --
> > 2.34.1
> >


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