microwatt: Updated section on running Linux kernel.

diff --git a/HDL_workflow/microwatt.mdwn b/HDL_workflow/microwatt.mdwn
index b00f2b84e9e045550ded5c8b9cf1274ddf6d0b9f..b3abca890a0438dfe9ff999e48e87d845a546847 100644 (file)
--- a/HDL_workflow/microwatt.mdwn
+++ b/HDL_workflow/microwatt.mdwn
@@ -277,7 +277,15 @@ A few examples:
 
 ## Running Linux kernel - TODO: Need to check
 
-### Building the kernel
+To run Linux on Microwatt, you'll need two binaries:
+
+- The `sdram_init.bin`, which is easy to compile (no additional software
+required).
+
+- The `dtbImage.microwatt` device tree Linux kernel. This can be compiled (see
+below), or a copy can be downloaded from: <https://ftp.libre-soc.org/dtbImage.microwatt>.
+
+### Building the kernel - TODO:
 On a POWER9 there is no need to install gcc-powerpc64le-linux-gnu, 
 you can omit CROSS_COMPILE and ARCH in this case
 
@@ -295,16 +303,24 @@ This will produce a file
        microwatt/arch/powerpc/boot/dtbImage.microwatt
 
 ### Building sdram_init.bin
-This needs gcc-powerpc64le-linux-gnu if cross compilation is used.
+This needs gcc-powerpc64le-linux-gnu (already included in the setup step) if
+cross compilation is used. It is assumed you're already in `~/src/microwatt/`
+directory.
 
-       cd microwatt
-       cd litedram/gen-src/sdram_init/
-       make
+    (microwatt):$ cd litedram/gen-src/sdram_init/
+       (microwatt):$ make
+
+The resulting binary will be in the `obj/` directory.
 
 ### Running the simulation
 
-       cp microwatt/arch/powerpc/boot/dtbImage.microwatt
-       ./microwatt-verilator sdram_init.bin dtbImage.microwatt
+Make sure to return back to `src/microwatt/`.
+
+    (microwatt):$ cd ~/src/microwatt/
+       (microwatt):$ cp microwatt/arch/powerpc/boot/dtbImage.microwatt
+       (microwatt):$ ./microwatt-verilator sdram_init.bin dtbImage.microwatt
+
+This will take some time...
 
 ### TODO: buildroot