microwatt: Add a bit more to Linux section.

diff --git a/HDL_workflow/microwatt.mdwn b/HDL_workflow/microwatt.mdwn
index c4eb1e8461dc4083c368f7fd4348a8c64e010866..8c393b2e9549c2e895d79a2805c349b869f0b19a 100644 (file)
--- a/HDL_workflow/microwatt.mdwn
+++ b/HDL_workflow/microwatt.mdwn
@@ -289,7 +289,7 @@ Then compile verilator sim binary as before:
        export GHDLSYNTH=ghdl
        make microwatt-verilator
 
-## Running Linux kernel - TODO: Need to check
+## Running Linux kernel
 
 To run Linux on Microwatt, you'll need two binaries:
 
@@ -299,7 +299,22 @@ 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>.
 
+Like with the micropython example, you'll need to increase the RAM size in the
+makefile, and recompile the microwatt-verilator binary.
+
+Uncomment the following:
+
+    MEMORY_SIZE=536870912
+
+Which will change the RAM size to 512KiB.
+
+As there is no `dtbImage.microwatt.hex`, you can leave `RAM_INIT_FILE` unchanged.
+
 ### Building the kernel - TODO:
+
+*(Please don't build the kernel yourself, until you've tested with the existing kernel linked
+above!)*
+
 On a POWER9 there is no need to install gcc-powerpc64le-linux-gnu, 
 you can omit CROSS_COMPILE and ARCH in this case
 
@@ -322,7 +337,7 @@ cross compilation is used. It is assumed you're already in `~/src/microwatt/`
 directory.
 
     (microwatt):$ cd litedram/gen-src/sdram_init/
-       (microwatt):$ make
+    (microwatt):$ make
 
 The resulting binary will be in the `obj/` directory.
 
@@ -331,8 +346,8 @@ The resulting binary will be in the `obj/` directory.
 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
+    (microwatt):$ cp microwatt/arch/powerpc/boot/dtbImage.microwatt
+    (microwatt):$ ./microwatt-verilator sdram_init.bin dtbImage.microwatt
 
 This will take some time...