test/py: add MMC/SD block read test

Add a standalone MMC block read test. This allows direct testing of MMC
access rather than relying on doing so as a side-effect of e.g. DFU or
UMS testing, which may not be enabled on all platforms.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

test/py/tests/test_mmc_rd.py

@@ -0,0 +1,129 @@
+# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0
+
+# Test U-Boot's "mmc read" command. The test reads data from the eMMC or SD
+# card, and validates the no errors occurred, and that the expected data was
+# read if the test configuration contains a CRC of the expected data.
+
+import pytest
+import u_boot_utils
+
+"""
+This test relies on boardenv_* to containing configuration values to define
+which MMC devices should be tested. For example:
+
+env__mmc_rd_configs = (
+    {
+        "fixture_id": "emmc-boot0",
+        "is_emmc": True,
+        "devid": 0,
+        "partid": 1,
+        "sector": 0x10,
+        "count": 1,
+    },
+    {
+        "fixture_id": "emmc-boot1",
+        "is_emmc": True,
+        "devid": 0,
+        "partid": 2,
+        "sector": 0x10,
+        "count": 1,
+    },
+    {
+        "fixture_id": "emmc-data",
+        "is_emmc": True,
+        "devid": 0,
+        "partid": 0,
+        "sector": 0x10,
+        "count": 0x1000,
+    },
+    {
+        "fixture_id": "sd-mbr",
+        "is_emmc": False,
+        "devid": 1,
+        "partid": None,
+        "sector": 0,
+        "count": 1,
+        "crc32": "8f6ecf0d",
+    },
+    {
+        "fixture_id": "sd-large",
+        "is_emmc": False,
+        "devid": 1,
+        "partid": None,
+        "sector": 0x10,
+        "count": 0x1000,
+    },
+)
+"""
+
+@pytest.mark.buildconfigspec('cmd_mmc')
+def test_mmc_rd(u_boot_console, env__mmc_rd_config):
+    """Test the "mmc read" command.
+
+    Args:
+        u_boot_console: A U-Boot console connection.
+        env__mmc_rd_config: The single MMC configuration on which
+            to run the test. See the file-level comment above for details
+            of the format.
+
+    Returns:
+        Nothing.
+    """
+
+    is_emmc = env__mmc_rd_config['is_emmc']
+    devid = env__mmc_rd_config['devid']
+    partid = env__mmc_rd_config.get('partid', 0)
+    sector = env__mmc_rd_config.get('sector', 0)
+    count_sectors = env__mmc_rd_config.get('count', 1)
+    expected_crc32 = env__mmc_rd_config.get('crc32', None)
+
+    count_bytes = count_sectors * 512
+    bcfg = u_boot_console.config.buildconfig
+    has_cmd_memory = bcfg.get('config_cmd_memory', 'n') == 'y'
+    has_cmd_crc32 = bcfg.get('config_cmd_crc32', 'n') == 'y'
+    ram_base = u_boot_utils.find_ram_base(u_boot_console)
+    addr = '0x%08x' % ram_base
+
+    # Select MMC device
+    cmd = 'mmc dev %d' % devid
+    if is_emmc:
+        cmd += ' %d' % partid
+    response = u_boot_console.run_command(cmd)
+    assert 'no card present' not in response
+    if is_emmc:
+        partid_response = "(part %d)" % partid
+    else:
+        partid_response = ""
+    good_response = 'mmc%d%s is current device' % (devid, partid_response)
+    assert good_response in response
+
+    # Clear target RAM
+    if expected_crc32:
+        if has_cmd_memory and has_cmd_crc32:
+            cmd = 'mw.b %s 0 0x%x' % (addr, count_bytes)
+            u_boot_console.run_command(cmd)
+
+            cmd = 'crc32 %s 0x%x' % (addr, count_bytes)
+            response = u_boot_console.run_command(cmd)
+            assert expected_crc32 not in response
+        else:
+            u_boot_console.log.warning(
+                'CONFIG_CMD_MEMORY or CONFIG_CMD_CRC32 != y: Skipping RAM clear')
+
+    # Read data
+    cmd = 'mmc read %s %x %x' % (addr, sector, count_sectors)
+    response = u_boot_console.run_command(cmd)
+    good_response = 'MMC read: dev # %d, block # %d, count %d ... %d blocks read: OK' % (
+        devid, sector, count_sectors, count_sectors)
+    assert good_response in response
+
+    # Check target RAM
+    if expected_crc32:
+        if has_cmd_crc32:
+            cmd = 'crc32 %s 0x%x' % (addr, count_bytes)
+            response = u_boot_console.run_command(cmd)
+            assert expected_crc32 in response
+        else:
+            u_boot_console.log.warning('CONFIG_CMD_CRC32 != y: Skipping check')