[PATCH] RISC-V: virt: riscvemu: add interactive tutorial

Thu Feb 24 05:52:46 PST 2022

This tutorial walks the user through basics of the barebox shell.
It can be invoked using the next command.

It will be extended later to cover actual boot as well, but
that part still needs to be added to the web demo. To try it out
interactively, go to:

  https://www.barebox.org/jsbarebox/

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/riscv/boards/riscvemu/Makefile                  |  1 +
 arch/riscv/boards/riscvemu/board.c                   |  4 ++++
 .../defaultenv-riscvemu/data/tutorial/00-init        | 12 ++++++++++++
 .../defaultenv-riscvemu/data/tutorial/01-interactive |  7 +++++++
 .../defaultenv-riscvemu/data/tutorial/02-ofdump      |  6 ++++++
 .../defaultenv-riscvemu/data/tutorial/03-devinfo     |  5 +++++
 .../defaultenv-riscvemu/data/tutorial/04-cs0         | 11 +++++++++++
 .../defaultenv-riscvemu/data/tutorial/05-drvinfo     |  4 ++++
 .../defaultenv-riscvemu/data/tutorial/06-devinfo-dev |  6 ++++++
 .../riscvemu/defaultenv-riscvemu/data/tutorial/07-mw |  9 +++++++++
 .../defaultenv-riscvemu/data/tutorial/08-devfs       |  8 ++++++++
 .../defaultenv-riscvemu/data/tutorial/09-partitions  |  9 +++++++++
 .../defaultenv-riscvemu/data/tutorial/10-environment |  8 ++++++++
 .../defaultenv-riscvemu/data/tutorial/11-env-data    | 12 ++++++++++++
 .../defaultenv-riscvemu/data/tutorial/12-dmesg       |  9 +++++++++
 .../defaultenv-riscvemu/data/tutorial/13-env-bin     | 11 +++++++++++
 .../defaultenv-riscvemu/data/tutorial/14-env-init    |  8 ++++++++
 .../defaultenv-riscvemu/data/tutorial/15-magicvar    | 10 ++++++++++
 .../defaultenv-riscvemu/data/tutorial/16-env-nv      | 12 ++++++++++++
 .../defaultenv-riscvemu/data/tutorial/17-env-saveenv |  7 +++++++
 .../defaultenv-riscvemu/data/tutorial/17-env-usage   |  5 +++++
 .../defaultenv-riscvemu/data/tutorial/18-mnt         | 11 +++++++++++
 .../defaultenv-riscvemu/data/tutorial/19-automount   |  9 +++++++++
 .../defaultenv-riscvemu/data/tutorial/20-mount-fs    | 11 +++++++++++
 .../defaultenv-riscvemu/data/tutorial/21-state       | 11 +++++++++++
 .../data/tutorial/22-device-params                   | 11 +++++++++++
 .../data/tutorial/23-device-param-types              |  8 ++++++++
 .../defaultenv-riscvemu/data/tutorial/24-boot        | 12 ++++++++++++
 .../defaultenv-riscvemu/data/tutorial/99-end         |  1 +
 .../defaultenv-riscvemu/init/90-tutorial-intro       |  6 ++++++
 30 files changed, 244 insertions(+)
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/00-init
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/01-interactive
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/02-ofdump
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/03-devinfo
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/04-cs0
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/05-drvinfo
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/06-devinfo-dev
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/07-mw
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/08-devfs
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/09-partitions
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/10-environment
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/11-env-data
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/12-dmesg
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/13-env-bin
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/14-env-init
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/15-magicvar
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/16-env-nv
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-saveenv
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-usage
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/18-mnt
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/19-automount
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/20-mount-fs
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/21-state
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/22-device-params
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/23-device-param-types
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/24-boot
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/99-end
 create mode 100644 arch/riscv/boards/riscvemu/defaultenv-riscvemu/init/90-tutorial-intro

diff --git a/arch/riscv/boards/riscvemu/Makefile b/arch/riscv/boards/riscvemu/Makefile
index 75f52ada8f37..56949c2357c8 100644
--- a/arch/riscv/boards/riscvemu/Makefile
+++ b/arch/riscv/boards/riscvemu/Makefile
@@ -2,3 +2,4 @@
 
 obj-y += board.o
 obj-y += overlay-of-sram.dtb.o
+bbenv-$(CONFIG_CMD_TUTORIAL) += defaultenv-riscvemu
diff --git a/arch/riscv/boards/riscvemu/board.c b/arch/riscv/boards/riscvemu/board.c
index 31d0c70be643..d9c7bd77b8cc 100644
--- a/arch/riscv/boards/riscvemu/board.c
+++ b/arch/riscv/boards/riscvemu/board.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <driver.h>
+#include <envfs.h>
 #include <poweroff.h>
 #include <restart.h>
 #include <deep-probe.h>
@@ -45,6 +46,9 @@ static int riscvemu_probe(struct device_d *dev)
 	of_overlay_apply_tree(dev->device_node, overlay);
 	/* of_probe() will happen later at of_populate_initcall */
 
+	if (IS_ENABLED(CONFIG_CMD_TUTORIAL))
+		defaultenv_append_directory(defaultenv_riscvemu);
+
 	of_chosen = of_find_node_by_path("/chosen");
 
 	if (of_property_read_u64(of_chosen, "riscv,kernel-start", &start))
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/00-init b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/00-init
new file mode 100644
index 000000000000..1ff43142bada
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/00-init
@@ -0,0 +1,12 @@
+
+You are using Hush, barebox' default shell. You are currently using it
+interactively, but it can execute scripts as part of the startup and boot
+procedure as well. See for yourself:
+```
+  cat /env/init/90-tutorial-intro
+```
+Look around as you like. When you are ready to continue the tutorial,
+type `next` again. The `prev` command does the inverse and shows previous
+tutorial steps. The `help` command will show help usage text,
+e.g. `help next`.
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/01-interactive b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/01-interactive
new file mode 100644
index 000000000000..8b285cd9f475
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/01-interactive
@@ -0,0 +1,7 @@
+
+The interactive shell, its commands and the nodes in the virtual
+file system they operate on enable quick UNIX-like prototyping
+and debugging. Let's give it a try, shall we?
+Type `of_dump` to list the open firmware (OF) device tree barebox
+used to discover the hardware and `next` to continue the tutorial.
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/02-ofdump b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/02-ofdump
new file mode 100644
index 000000000000..3271f734b20b
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/02-ofdump
@@ -0,0 +1,6 @@
+
+That's a lot of output, so let's restrict ourselves to just part
+of the tree:
+```
+  of_dump /soc/virtio at 40010000
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/03-devinfo b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/03-devinfo
new file mode 100644
index 000000000000..74bc9aa88a67
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/03-devinfo
@@ -0,0 +1,5 @@
+
+This node tells barebox enough information to instantiate a device and
+to try match it with existing drivers. Type `devinfo` to see the tree of
+devices known to barebox.
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/04-cs0 b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/04-cs0
new file mode 100644
index 000000000000..0ac452d1b3b5
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/04-cs0
@@ -0,0 +1,11 @@
+
+In this tree, you will find 40010000.virtio at 40010000.of, the
+device corresponding to the device tree node we've just seen.
+Devices can themself have child devices. This device's
+grandchild is `cs0`, the virtual console device that prints
+you this very text.
+
+See for yourself:
+```
+  echo -a /dev/cs0 Append this text to virtio console
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/05-drvinfo b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/05-drvinfo
new file mode 100644
index 000000000000..068bf303d8cd
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/05-drvinfo
@@ -0,0 +1,4 @@
+
+Let's look at more devices. Type `drvinfo` to see what drivers are
+available and what devices they were successfully matched with.
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/06-devinfo-dev b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/06-devinfo-dev
new file mode 100644
index 000000000000..f706915ba2e8
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/06-devinfo-dev
@@ -0,0 +1,6 @@
+
+Let's pick another device out of the list: HTIF. We can display some extra
+info with `devinfo`. (Use the tab completion to avoid writing it all out!)
+```
+devinfo 40008000.htif.of
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/07-mw b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/07-mw
new file mode 100644
index 000000000000..4278f8f391bd
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/07-mw
@@ -0,0 +1,9 @@
+
+We see that the device has a memory mapped I/O region of 8 bytes that
+can be used for communication. Poking 0x010100000000002e in little-
+endian into that region should print a period '.'.
+Let's do that quad-word memory write (`mw -q`) 80 times by having a shell
+local variable keep count:
+```
+i=0; while [ $i -lt 80 ]; do mw -q 0x40008000 0x010100000000002e; let i=$i+1; done
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/08-devfs b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/08-devfs
new file mode 100644
index 000000000000..b117e4bb1632
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/08-devfs
@@ -0,0 +1,8 @@
+
+`mw` is complemented by `md` for memory display. There are further commands
+like `mm` (memory modify), `memcpy` and `memcmp` (copy/compare ranges).
+These commands operate on `/dev/mem` by default, but any seekable device
+or file can be used instead. Let's see what device files we got here:
+```
+ls /dev
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/09-partitions b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/09-partitions
new file mode 100644
index 000000000000..552ab2ab1e51
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/09-partitions
@@ -0,0 +1,9 @@
+
+The `mtdram0` looks interesting. That's the 64K SRAM at the start of the
+address space. The virtual machine places the boot "rom" there as well
+as the flattened (compiled) device tree (FDT). barebox can be informed
+about partitioning and will create extra devices for each partition.
+This allows you to reference them from commands easily:
+```
+of_dump -f /dev/mtdram0.fdt
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/10-environment b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/10-environment
new file mode 100644
index 000000000000..d1a6f85119f7
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/10-environment
@@ -0,0 +1,8 @@
+
+Not all of the 64K is used, so the barebox board support here uses
+the unused mtd-ram space for saving modified environment and state.
+The barebox environment is a file system which contains scripts, variables
+and data:
+```
+ls -R /env
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/11-env-data b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/11-env-data
new file mode 100644
index 000000000000..81e3f47ee781
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/11-env-data
@@ -0,0 +1,12 @@
+
+The environment you see here is the built-in environment barebox was
+compiled with. It contains default values for non-volatile variables,
+(init) scripts and data. It's generated from directories on the host
+system specified during build and stored as an archive within
+barebox. This environment may also be compressed allowing shipping
+larger files and even binaries. For example, this barebox binary
+has the option CONFIG_DEFAULT_ENVIRONMENT_GENERIC_NEW_IKCONFIG=y,
+which ships a copy of the used barebox configuration. See for yourself:
+```
+cat /env/data/config
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/12-dmesg b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/12-dmesg
new file mode 100644
index 000000000000..61cdd2adafbc
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/12-dmesg
@@ -0,0 +1,9 @@
+
+In the field, you will probably want to depend exclusively on the built-in
+environment, but it can be very handy to persist environment changes during
+development. You may recall that barebox told us at first boot that the
+environment was never written?  If you don't, no problem, log messages are,
+you guessed it, logged:
+```
+dmesg
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/13-env-bin b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/13-env-bin
new file mode 100644
index 000000000000..34b7ab554b7f
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/13-env-bin
@@ -0,0 +1,11 @@
+
+Let's modify the environment to add a new script (Remember
+`help` can show you the usage, e.g. `help mw`):
+```
+cd /env/bin
+echo -o putc '#!/bin/sh'
+echo -a putc 'mw -l 0x40008000 $1'
+echo -a putc 'mw -l 0x40008004 0x01010000'
+cd /
+putc 0x40 # Print an @ character
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/14-env-init b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/14-env-init
new file mode 100644
index 000000000000..184a4f571f8b
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/14-env-init
@@ -0,0 +1,8 @@
+
+We could have added the last script anywhere in `/env`. But `/env/bin` is
+already in the executable search `PATH`, so you don't have to write out
+the full path when invoking the script. Another special directory is
+`/env/init`. Anything there will be sourced on shell startup.
+Let's poke the HTIF a bit every time we start: Open a new file with
+`edit /env/init/99-percent` and type into it `putc 0x40`.
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/15-magicvar b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/15-magicvar
new file mode 100644
index 000000000000..ec2912da9fb9
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/15-magicvar
@@ -0,0 +1,10 @@
+
+As init scripts only run on initialization, we'll have to do a reset to
+see them in action. But first, we'll want to save our tutorial progress.
+This happens via $global.variables.  Many parts of barebox monitor reads
+and writes to such variables to make information available to the shell.
+
+The `next` command also does it. How would you know?
+```
+magicvar
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/16-env-nv b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/16-env-nv
new file mode 100644
index 000000000000..3440e0194722
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/16-env-nv
@@ -0,0 +1,12 @@
+
+Now that you know that $global.tutorial.step holds the next step, you
+will want to initialize it on the next reset. We could write an init shell
+script for that, but there is something much more convenient:
+
+On startup, barebox needs to assign initial values for each
+$global.variable; if a suitably named non-volatile $nv.variable already
+exists, it will be used as initial value. Let's see what global variables
+we got (leading asterisk '*' means it was initialized from NV):
+```
+global
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-saveenv b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-saveenv
new file mode 100644
index 000000000000..f929838138d6
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-saveenv
@@ -0,0 +1,7 @@
+
+Now that we have written a normal script and an init script, add a
+nv variable to the mix, save the environment and reset to see them
+all in action:
+```
+nv tutorial.step=$global.tutorial.step; saveenv; reset
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-usage b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-usage
new file mode 100644
index 000000000000..1f4ff37f8652
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/17-env-usage
@@ -0,0 +1,5 @@
+
+Welcome back! You have successfully saved the environment. Make sure
+to reset your environment with `saveenv -z` when you are done. You wouldn't
+want to chase ghosts, because you changed an init script and forgot about it. :)
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/18-mnt b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/18-mnt
new file mode 100644
index 000000000000..3122e6ffa404
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/18-mnt
@@ -0,0 +1,11 @@
+
+We now have seen `/dev`, which holds the devfs, and `/env` which holds the
+active environment. `/tmp` is as you have guessed it a directory where temporary
+files can be placed. `/pstore` is short for persistent storage, a Linux
+mechanism to store and retrieve error records even after a kernel panic.
+
+This leaves `/mnt`. Let's take a peek at it as well at our active mounts:
+```
+mount
+ls /mnt
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/19-automount b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/19-automount
new file mode 100644
index 000000000000..4d4787a9a8c7
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/19-automount
@@ -0,0 +1,9 @@
+
+Strangely, nothing inside `/mnt` is seen in the `mount` output. Why you
+ask? Because these are automounts that are deferred until first access.
+So when you `bootm /mnt/nfs/boot/Image.gz` the first time, barebox will
+bring up the network and mount the network file system (provided you do
+have network). We can list what automounts there are:
+```
+automount -l
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/20-mount-fs b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/20-mount-fs
new file mode 100644
index 000000000000..cc5e64c66c78
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/20-mount-fs
@@ -0,0 +1,11 @@
+
+`/mnt/virtioblk0` is an interesting one. Block device partitions
+automatically get automount entries created. On first access,
+barebox will determine what file system is located in the partition
+and mount it. Thus you can just use `/mnt/virtioblk0/DOOM1.WAD` in
+your script and not incur the overhead of mounting unless it's accessed:
+```
+mount
+ll /mnt/virtioblk0/DOOM1.WAD
+mount
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/21-state b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/21-state
new file mode 100644
index 000000000000..1a71204cf5e1
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/21-state
@@ -0,0 +1,11 @@
+
+You'll note most file systems in barebox are read-only. While those that aren't
+could be used with `saveenv` to store a packed environment for Linux use, that's
+murky waters: atomicity, limiting scope, authentication and journal handling
+complicate things. barebox state is the mechanism how barebox stores variables
+(and only variables) in a power-fail safe manner that's also accessible to Linux.
+
+Check the `state` device:
+```
+devinfo state
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/22-device-params b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/22-device-params
new file mode 100644
index 000000000000..3f8d31f171d0
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/22-device-params
@@ -0,0 +1,11 @@
+
+The state driver parses the device tree to learn the state layout
+and how it's (redundantly) placed. The information it learns are
+registered with the device as device parameters. Device Parameters
+make it easy to interact with the shell. For example, the MAC address
+of a network adapter is a device parameter. We already saw some other
+device parameters before. Those of the global and nv device:
+```
+devinfo global
+devinfo nv
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/23-device-param-types b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/23-device-param-types
new file mode 100644
index 000000000000..36a311d011ac
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/23-device-param-types
@@ -0,0 +1,8 @@
+
+Many device parameters are simple strings, some have specific types
+and run actions on read/write or accept only specific values.
+`devinfo` will show you what type a variable has and writing an
+invalid value will give you an error:
+```
+global.tutorial.step=non-existent
+```
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/24-boot b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/24-boot
new file mode 100644
index 000000000000..90c226697310
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/24-boot
@@ -0,0 +1,12 @@
+
+You should now know enough about barebox' architecture, that
+we could talk about barebox' actual function without it
+seeming too magical: Booting.
+
+We still need to add that part to the tutorial though, but you
+can check out `help boot`, `help bootm` as well as the barebox
+documentation linked below. Also give the graphical mode a
+try!
+
+Tutorial to be continued..
+
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/99-end b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/99-end
new file mode 100644
index 000000000000..4744f2b3eeb8
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/data/tutorial/99-end
@@ -0,0 +1 @@
+End of tutorial reached!
diff --git a/arch/riscv/boards/riscvemu/defaultenv-riscvemu/init/90-tutorial-intro b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/init/90-tutorial-intro
new file mode 100644
index 000000000000..716905534c94
--- /dev/null
+++ b/arch/riscv/boards/riscvemu/defaultenv-riscvemu/init/90-tutorial-intro
@@ -0,0 +1,6 @@
+source /env/data/ansi-colors
+
+echo -e $YELLOW
+echo -e This is the barebox shell. See ${RED}help${YELLOW} for a listing of commands.
+echo -e Type ${RED}next${YELLOW} for the next tutorial tip.
+echo -e $NC
-- 
2.30.2


