[U-Boot] [PATCH 07/14] efi_loader: Add disk interfaces

Alexander Graf
2016-01-15T05:06:13Z

A EFI applications usually want to access storage devices to load data from.

This patch adds support for EFI disk interfaces. It loops through all block
storage interfaces known to U-Boot and creates an EFI object for each existing
one. EFI applications can then through these objects call U-Boot's read and
write functions.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

---

v1 -> v2:

- Move to block_drvr array
- Move to GPLv2+
- Fix header order
- Document efi block object struct
- Use calloc rather than malloc & memset
---
include/efi_loader.h | 1 +
lib/efi_loader/efi_disk.c | 218 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 219 insertions(+)
create mode 100644 lib/efi_loader/efi_disk.c

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 0f821ff..9d6c322 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -63,6 +63,7 @@ struct efi_object {
};
extern struct list_head efi_obj_list;

+int efi_disk_register(void);
efi_status_t efi_return_handle(void *handle,
efi_guid_t *protocol, void **protocol_interface,
void *agent_handle, void *controller_handle,
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
new file mode 100644
index 0000000..c589604
--- /dev/null
+++ b/lib/efi_loader/efi_disk.c
@@ -0,0 +1,218 @@
+/*
+ * EFI application disk support
+ *
+ * Copyright (c) 2016 Alexander Graf
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+#include <inttypes.h>
+#include <part.h>
+#include <malloc.h>
+
+static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
+
+struct efi_disk_obj {
+ /* Generic EFI object parent class data */
+ struct efi_object parent;
+ /* EFI Interface callback struct for block I/O */
+ struct efi_block_io ops;
+ /* U-Boot ifname for block device */
+ const char *ifname;
+ /* U-Boot dev_index for block device */
+ int dev_index;
+ /* EFI Interface Media descriptor struct, referenced by ops */
+ struct efi_block_io_media media;
+ /* EFI device path to this block device */
+ struct efi_device_path_file_path *dp;
+};
+
+static void ascii2unicode(u16 *unicode, char *ascii)
+{
+ while (*ascii)
+ *(unicode++) = *(ascii++);
+}
+
+static efi_status_t efi_disk_open_block(void *handle, efi_guid_t *protocol,
+ void **protocol_interface, void *agent_handle,
+ void *controller_handle, uint32_t attributes)
+{
+ struct efi_disk_obj *diskobj = handle;
+
+ *protocol_interface = &diskobj->ops;
+
+ return EFI_SUCCESS;
+}
+
+static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
+ void **protocol_interface, void *agent_handle,
+ void *controller_handle, uint32_t attributes)
+{
+ struct efi_disk_obj *diskobj = handle;
+
+ *protocol_interface = diskobj->dp;
+
+ return EFI_SUCCESS;
+}
+
+static efi_status_t efi_disk_reset(struct efi_block_io *this,
+ char extended_verification)
+{
+ EFI_ENTRY("%p, %x", this, extended_verification);
+ return EFI_EXIT(EFI_DEVICE_ERROR);
+}
+
+enum efi_disk_direction {
+ EFI_DISK_READ,
+ EFI_DISK_WRITE,
+};
+
+static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
+ u32 media_id, u64 lba, unsigned long buffer_size,
+ void *buffer, enum efi_disk_direction direction)
+{
+ struct efi_disk_obj *diskobj;
+ struct block_dev_desc *desc;
+ int blksz;
+ int blocks;
+ unsigned long n;
+
+ EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
+ buffer_size, buffer);
+
+ diskobj = container_of(this, struct efi_disk_obj, ops);
+ if (!(desc = get_dev(diskobj->ifname, diskobj->dev_index)))
+ return EFI_EXIT(EFI_DEVICE_ERROR);
+ blksz = desc->blksz;
+ blocks = buffer_size / blksz;
+
+#ifdef DEBUG_EFI
+ printf("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
+ __LINE__, blocks, lba, blksz, direction);
+#endif
+
+ /* We only support full block access */
+ if (buffer_size & (blksz - 1))
+ return EFI_EXIT(EFI_DEVICE_ERROR);
+
+ if (direction == EFI_DISK_READ)
+ n = desc->block_read(desc->dev, lba, blocks, buffer);
+ else
+ n = desc->block_write(desc->dev, lba, blocks, buffer);
+
+ /* We don't do interrupts, so check for timers cooperatively */
+ efi_timer_check();
+
+#ifdef DEBUG_EFI
+ printf("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
+#endif
+ if (n != blocks)
+ return EFI_EXIT(EFI_DEVICE_ERROR);
+
+ return EFI_EXIT(EFI_SUCCESS);
+}
+
+static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
+ u32 media_id, u64 lba, unsigned long buffer_size,
+ void *buffer)
+{
+ return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
+ EFI_DISK_READ);
+}
+
+static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
+ u32 media_id, u64 lba, unsigned long buffer_size,
+ void *buffer)
+{
+ return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
+ EFI_DISK_WRITE);
+}
+
+static efi_status_t efi_disk_flush_blocks(struct efi_block_io *this)
+{
+ /* We always write synchronously */
+ return EFI_SUCCESS;
+}
+
+static const struct efi_block_io block_io_disk_template = {
+ .reset = &efi_disk_reset,
+ .read_blocks = &efi_disk_read_blocks,
+ .write_blocks = &efi_disk_write_blocks,
+ .flush_blocks = &efi_disk_flush_blocks,
+};
+
+/*
+ * U-Boot doesn't have a list of all online disk devices. So when running our
+ * EFI payload, we scan through all of the potentially available ones and
+ * store them in our object pool.
+ *
+ * This gets called from do_bootefi_exec().
+ */
+int efi_disk_register(void)
+{
+ const struct block_drvr *cur_drvr;
+ int i;
+ int disks = 0;
+
+ /* Search for all available disk devices */
+ for (cur_drvr = block_drvr; cur_drvr->name; cur_drvr++) {
+ printf("Scanning disks on %s...\n", cur_drvr->name);
+ for (i = 0; i < 4; i++) {
+ block_dev_desc_t *desc;
+ struct efi_disk_obj *diskobj;
+ struct efi_device_path_file_path *dp;
+ int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
+ char devname[16];
+
+ desc = get_dev(cur_drvr->name, i);
+ if (!desc)
+ continue;
+
+ diskobj = calloc(1, objlen);
+
+ /* Fill in object data */
+
+ diskobj->parent.protocols[0].guid = &efi_block_io_guid;
+ diskobj->parent.protocols[0].open = efi_disk_open_block;
+ diskobj->parent.protocols[1].guid = &efi_guid_device_path;
+ diskobj->parent.protocols[1].open = efi_disk_open_dp;
+ diskobj->parent.handle = diskobj;
+ diskobj->ops = block_io_disk_template;
+ diskobj->ifname = cur_drvr->name;
+ diskobj->dev_index = i;
+
+ /* Fill in EFI IO Media info (for read/write callbacks) */
+
+ diskobj->media.removable_media = desc->removable;
+ diskobj->media.media_present = 1;
+ diskobj->media.block_size = desc->blksz;
+ diskobj->media.io_align = desc->blksz;
+ diskobj->media.last_block = desc->lba;
+ diskobj->ops.media = &diskobj->media;
+
+ /* Fill in device path */
+
+ dp = (void*)&diskobj[1];
+ diskobj->dp = dp;
+ dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
+ dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
+ dp[0].dp.length = sizeof(*dp);
+ sprintf(devname, "%s%d", cur_drvr->name, i);
+ ascii2unicode(dp[0].str, devname);
+
+ dp[1].dp.type = DEVICE_PATH_TYPE_END;
+ dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
+ dp[1].dp.length = sizeof(*dp);
+
+ /* Hook up to the device list */
+
+ list_add_tail(&diskobj->parent.link, &efi_obj_list);
+ disks++;
+ }
+ }
+ printf("Found %d disks\n", disks);
+
+ return 0;
+}
--
2.1.4