[PATCH 16/17] doc: smh: Update semihosting documentation

[Sean Anderson]

This documents the new semihosting features added in the past few
commits.

Signed-off-by: Sean Anderson <sean.anderson at seco.com>
---

 doc/usage/semihosting.rst | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/doc/usage/semihosting.rst b/doc/usage/semihosting.rst
index ed16e4d582..986a821819 100644
--- a/doc/usage/semihosting.rst
+++ b/doc/usage/semihosting.rst
@@ -34,10 +34,18 @@ Foundation and Base fastmodel simulators.
 Loading files
 -------------
 
-The semihosting code adds a "hostfs"::
+The semihosting code adds a "semihosting filesystem"::
 
-  smhload <image> <address> [env var]
+  load hostfs <address> <image>
 
 That will load an image from the host filesystem into RAM at the specified
-address and optionally store the load end address in the specified
-environment variable.
+address. If you are using U-Boot SPL, you can also use ``BOOT_DEVICE_SMH``
+which will load ``CONFIG_SPL_FS_LOAD_PAYLOAD_NAME``.
+
+Host console
+------------
+
+U-Boot can use the host's console instead of a physical serial device by
+enabling ``CONFIG_SERIAL_SEMIHOSTING``. If you don't have
+``CONFIG_DM_SERIAL`` enabled, make sure you disable any other serial
+drivers.
-- 
2.25.1