Apparent conflict between CONFIG_BLK and CONFIG_API

Good evening,

I am trying to port FreeBSD to the ASUS Tinker Board, a computer based
on the Rockchip 3288 SoC. FreeBSD's boot loader (named loader(8)) needs
CONFIG_API to be enabled, but trying to build an U-Boot from trunk with
both CONFIG_API and CONFIG_BLK (as required for Rockchip SoC's?) leads
to the following build failure:

$ CROSS_COMPILE=arm-none-eabi- gmake tinker-rk3288_defconfig all
...
  CC      api/api_storage.o
api/api_storage.c: In function 'dev_read_stor':
api/api_storage.c:334:9: error: 'struct blk_desc' has no member named 'block_read'
  if ((dd->block_read) == NULL) {
         ^~
api/api_storage.c:339:11: error: 'struct blk_desc' has no member named 'block_read'
  return dd->block_read(dd, start, len, buf);
           ^~
api/api_storage.c:340:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
gmake[2]: *** [scripts/Makefile.build:281: api/api_storage.o] Fehler 1
gmake[1]: *** [Makefile:1229: api] Fehler 2
gmake: *** [Makefile:460: __build_one_by_one] Error 2

I applied the following fix, but the product doesn't boot. Perhaps
that's not a property of the fix though:

Yours,
Robert Clausecker

api/api_storage.c

@@ -331,10 +331,14 @@ lbasize_t dev_read_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start
 	if (!dev_stor_is_valid(type, dd))
 		return 0;
 
+#ifdef CONFIG_BLK
+	return blk_dread(dd, start, len, buf);
+#else
 	if ((dd->block_read) == NULL) {
 		debugf("no block_read() for device 0x%08x\n", cookie);
 		return 0;
 	}
 
 	return dd->block_read(dd, start, len, buf);
+#endif	/* defined(CONFIG_BLK) */
 }