[PATCH v7 5/9] efi_loader: support boot from URI device path

Masahisa Kojima masahisa.kojima at linaro.org
Wed Oct 18 10:32:44 CEST 2023


Hi Heinrich,


On Wed, 18 Oct 2023 at 09:42, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 16.10.23 08:45, 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).
> > Since boot option indicating the default file is automatically
> > created when new disk is detected, system can boot by selecting
> > the automatically created blkmap boot option.
> > If the file is PE-COFF file, load and start the downloaded file.
> >
> > The buffer used to download the ISO image file must be
> > reserved to avoid the unintended access to the image.
> > For PE-COFF file case, this memory reservation is done
> > in LoadImage Boot Service.
> >
> > Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> > ---
> >   include/efi_loader.h          |   2 +
> >   lib/efi_loader/Kconfig        |   9 ++
> >   lib/efi_loader/efi_bootmgr.c  | 198 ++++++++++++++++++++++++++++++++++
> >   lib/efi_loader/efi_dt_fixup.c |   2 +-
> >   4 files changed, 210 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index e24410505f..106006127b 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -554,6 +554,8 @@ void efi_runtime_detach(void);
> >   /* efi_convert_pointer() - convert pointer to virtual address */
> >   efi_status_t EFIAPI efi_convert_pointer(efi_uintn_t debug_disposition,
> >                                       void **address);
> > +/* add reserved memory to memory map */
> > +void efi_reserve_memory(u64 addr, u64 size, bool nomap);
> >   /* Carve out DT reserved memory ranges */
> >   void efi_carve_out_dt_rsv(void *fdt);
> >   /* Purge unused kaslr-seed */
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index d20aaab6db..5d99206dc3 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -479,4 +479,13 @@ config EFI_RISCV_BOOT_PROTOCOL
> >         replace the transfer via the device-tree. The latter is not
> >         possible on systems using ACPI.
> >
> > +config EFI_HTTP_BOOT
> > +     bool "EFI HTTP Boot support"
> > +     depends on CMD_DNS
> > +     depends on CMD_WGET
> > +     depends on BLKMAP
> > +     help
> > +       Enabling this option adds EFI HTTP Boot support. It allows to
> > +       directly boot from network.
> > +
> >   endif
> > diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> > index c8cf1c5506..c90b68f783 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 +172,192 @@ out:
> >       return ret;
> >   }
> >
> > +/**
> > + * mount_image() - mount the image with blkmap
> > + *
> > + * @lo_label:        u16 label string of load option
> > + * @image_addr:      image address
> > + * @image_size:      image size
> > + * Return:   pointer to the UCLASS_BLK udevice, NULL if failed
> > + */
> > +static struct udevice *mount_image(u16 *lo_label, ulong image_addr, int image_size)
> > +{
> > +     int err;
> > +     struct blkmap *bm;
> > +     struct udevice *bm_dev;
> > +     char *label = NULL, *p;
> > +
> > +     label = efi_alloc(utf16_utf8_strlen(lo_label) + 1);
> > +     if (!label)
> > +             return NULL;
> > +
> > +     p = label;
> > +     utf16_utf8_strcpy(&p, lo_label);
> > +     err = blkmap_create_ramdisk(label, image_addr, image_size, &bm_dev);
> > +     if (err) {
> > +             efi_free_pool(label);
> > +             return NULL;
> > +     }
> > +     bm = dev_get_plat(bm_dev);
> > +
> > +     efi_free_pool(label);
> > +
> > +     return bm->blk;
> > +}
> > +
> > +/**
> > + * load_mounted_image() - load mounted image with default file
> > + *
> > + * @devnum:  target blkmap device
> > + * @handle:  pointer to handle for newly installed image
> > + * Return:   status code
> > + */
> > +static efi_status_t load_mounted_image(int devnum, efi_handle_t *handle)
> > +{
> > +     u32 i;
> > +     u16 *bm_label, *p;
> > +     char device_name[12];
> > +     u16 *bootorder = NULL;
> > +     efi_uintn_t num, size;
> > +     void *load_option = NULL;
> > +     struct efi_load_option lo;
> > +     u16 varname[] = u"Boot####";
> > +     efi_status_t ret = EFI_NOT_FOUND;
> > +
> > +     snprintf(device_name, 12, "blkmap %d", devnum);
> > +     bm_label = calloc(1, (strlen(device_name) + 1) * sizeof(u16));
> > +     if (!bm_label)
> > +             return EFI_OUT_OF_RESOURCES;
> > +
> > +     p = bm_label;
> > +     utf8_utf16_strcpy(&p, device_name);
> > +
> > +     bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
> > +     if (!bootorder)
> > +             goto out;
> > +
> > +     num = size / sizeof(u16);
> > +     for (i = 0; i < num; i++) {
> > +             efi_create_indexed_name(varname, sizeof(varname), "Boot",
> > +                                     bootorder[i]);
> > +             load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
> > +             if (!load_option)
> > +                     continue;
> > +
> > +             ret = efi_deserialize_load_option(&lo, load_option, &size);
> > +             if (ret != EFI_SUCCESS) {
> > +                     free(load_option);
> > +                     continue;
> > +             }
> > +
> > +             /* check whether the label indicates the target blkmap device */
> > +             if (u16_strncmp(bm_label, lo.label, u16_strlen(bm_label))) {
> > +                     free(load_option);
> > +                     continue;
> > +             }
> > +
> > +             /* check whether the boot option is automatically generated */
> > +             if (guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated)) {
> > +                     free(load_option);
> > +                     continue;
> > +             }
> > +
> > +             ret = EFI_CALL(efi_load_image(true, efi_root, lo.file_path,
> > +                                           NULL, 0, handle));
> > +             free(load_option);
> > +             goto out;
> > +     }
> > +
> > +     if (i == num)
> > +             ret = EFI_NOT_FOUND;
> > +out:
> > +     free(bm_label);
> > +     free(bootorder);
> > +
> > +     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)
> > +{
> > +     char *s;
> > +     int err;
> > +     int uri_len;
> > +     u32 image_size;
> > +     efi_status_t ret;
> > +     ulong image_addr;
> > +
> > +     s = env_get("loadaddr");
> > +     if (!s) {
> > +             log_err("Error: loadaddr is not set\n");
> > +             return EFI_INVALID_PARAMETER;
> > +     }
> > +     image_addr = hextoul(s, NULL);
> > +     err = wget_with_dns(image_addr, uridp->uri);
> > +     if (err < 0)
> > +             return EFI_INVALID_PARAMETER;
> > +     image_size = env_get_hex("filesize", 0);
> > +     if (!image_size)
> > +             return EFI_INVALID_PARAMETER;
> > +
> > +     /*
> > +      * If the file extension is ".iso" or ".img", mount it and try to load
> > +      * the default file.
> > +      * If the file is PE-COFF image, load the downloaded file.
> > +      */
> > +     uri_len = strlen(uridp->uri);
> > +     if (!strncmp(&uridp->uri[uri_len - 4], ".iso", 4) ||
> > +         !strncmp(&uridp->uri[uri_len - 4], ".img", 4)) {
> > +             struct udevice *blk;
> > +             struct blk_desc *desc;
> > +
> > +             blk = mount_image(lo_label, image_addr, image_size);
> > +             if (!blk)
> > +                     return EFI_LOAD_ERROR;
> > +
> > +             /*
> > +              * When the new disk is detected, boot option is automatically
> > +              * created if it has a default file.
> > +              * Let's load the automatically created boot option.
> > +              */
> > +             desc = dev_get_uclass_plat(blk);
> > +             ret = load_mounted_image(desc->devnum, handle);
> > +             if (ret != EFI_SUCCESS)
> > +                     return ret;
> > +
> > +             /* whole ramdisk must be reserved */
> > +             efi_reserve_memory(image_addr, image_size, true);
>
> This comment is not enough to explain why you make the reservation.
>
> Our blkmap driver is gone after ExitBootServices().
> Why is EFI_LOADER_DATA not good enough?

In current implementation, this ramdisk is not passed to Linux,
so this whole ramdisk is not required to be reserved.

> How will the image be passed to Linux?

If the kernel supports 'pmem'(drivers/nvdimm/of_pmem.c), U-Boot can
expose the ramdisk.
For example, with the following 'pmem' device-tree node,
linux can mount the 256MB ramdisk starting from 0x90000000.

+        pmem at 90000000 {
+            compatible = "pmem-region";
+            reg = < 0x0 0x90000000 0x0 0x10000000 >;
+            volatile;
+        };

In my check, SUSE installer supports this pmem feature.
I will try to integrate this in this series.

Thanks,
Masahisa Kojima

>
> Best regards
>
> Heinrich
>
>
> > +     } else if (efi_check_pe((void *)image_addr, image_size, NULL) == EFI_SUCCESS) {
> > +             efi_handle_t mem_handle = NULL;
> > +             struct efi_device_path *file_path;
> > +
> > +             file_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
> > +                                         (uintptr_t)image_addr, image_size);
> > +             ret = efi_install_multiple_protocol_interfaces(
> > +                     &mem_handle, &efi_guid_device_path, file_path, NULL);
> > +             if (ret != EFI_SUCCESS)
> > +                     return ret;
> > +
> > +             ret = EFI_CALL(efi_load_image(false, efi_root, file_path,
> > +                                           (void *)image_addr, image_size,
> > +                                           handle));
> > +     } else {
> > +             log_err("Error: file type is not supported\n");
> > +             return EFI_UNSUPPORTED;
> > +     }
> > +
> > +     return ret;
> > +}
> > +
> >   /**
> >    * try_load_entry() - try to load image for boot option
> >    *
> > @@ -211,6 +401,14 @@ 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);
> > +             } else if (EFI_DP_TYPE(lo.file_path, MESSAGING_DEVICE, MSG_URI)) {
> > +                     if (IS_ENABLED(CONFIG_EFI_HTTP_BOOT))
> > +                             ret = try_load_from_uri_path(
> > +                                     (struct efi_device_path_uri *)
> > +                                             lo.file_path,
> > +                                     lo.label, handle);
> > +                     else
> > +                             ret = EFI_LOAD_ERROR;
> >               } else {
> >                       file_path = expand_media_path(lo.file_path);
> >                       ret = EFI_CALL(efi_load_image(true, efi_root, file_path,
> > diff --git a/lib/efi_loader/efi_dt_fixup.c b/lib/efi_loader/efi_dt_fixup.c
> > index 838023c78f..edc515b9ff 100644
> > --- a/lib/efi_loader/efi_dt_fixup.c
> > +++ b/lib/efi_loader/efi_dt_fixup.c
> > @@ -22,7 +22,7 @@ const efi_guid_t efi_guid_dt_fixup_protocol = EFI_DT_FIXUP_PROTOCOL_GUID;
> >    * @nomap:  indicates that the memory range shall not be accessed by the
> >    *          UEFI payload
> >    */
> > -static void efi_reserve_memory(u64 addr, u64 size, bool nomap)
> > +void efi_reserve_memory(u64 addr, u64 size, bool nomap)
> >   {
> >       int type;
> >       efi_uintn_t ret;
>


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