Rework main README.md

Author: phaubertin

README.md

@@ -11,8 +11,8 @@ The main build artifact that can be built from the code in this
 repository is the kernel image, which contains the kernel proper as well
 as the user space loader. The kernel image conforms to the
 [Linux x86 boot protocol](https://www.kernel.org/doc/Documentation/x86/boot.rst),
-which means it can be loaded by a bootloader intended
-for the Linux kernel, such as GRUB.
+which means it can be loaded by a bootloader intended for the Linux
+kernel, such as GRUB.
 
 During the boot process, the user space loader expects an initial RAM
 disk to have been loaded in memory by the bootloader. This would usually
@@ -27,19 +27,19 @@ that contains the kernel image and the initial RAM disk.
 Build Requirements
 ------------------
 
-To build the kernel image and test application, you will need a Linux
-machine with GNU make and a C compiler that can create 32-bit x86 ELF
-binaries. This software is known to build with GCC and clang.
+To build the kernel image and test application, you need a Linux machine
+with GNU make and a C compiler that can create 32-bit x86 ELF binaries.
+This software is known to build with GCC and clang.
 
-You will also need the Netwide Assembler (NASM).
+You also need the Netwide Assembler (NASM).
 
 If you wish to build the ISO image for use with QEMU, which is optional,
-you will need GRUB and GNU xorriso in addition to the above.
+you need GRUB and GNU xorriso in addition to the above.
 
 Run Time Requirements
 ---------------------
 
-To boot the Jinue microkernel, you will need either:
+To run this software, you need either:
 * QEMU; or
 * A x86 PC on which you have sufficient privileges to configure the boot
 manager to load Jinue.
@@ -54,71 +54,122 @@ the `--recurse-submodules` option when you clone the repository.
 ```
 git clone --recurse-submodules https://github.com/phaubertin/jinue.git
 ```
+
 Alternatively, if you already cloned the repository without passing this
-option, you can clone and initialize the submodules separately with the
-following command:
+option, you can initialize the submodules separately with the following
+command:
 
 ```
 git submodule update --init
 ```
 
 Then, configure the source code and its dependencies. You only need to
-do this oncen not each time you build.
+do this once, not each time you build.
+
 ```
 ./configure
 ```
 
 To build the ISO image for use with QEMU, build the `qemu` target with
 make:
+
 ```
 make qemu
 ```
+
+This builds the kernel image and the test application, and then creates
+a bootable ISO image.
+
 If you will not be using QEMU and only want to build the kernel image,
 this can be done with the default make target:
+
 ```
 make
 ```
 
+Similarly, the test application can be built separately with the
+`testapp` make target:
+
+```
+make testapp
+```
+
 How to Run in QEMU
 -------------------
 You can run the kernel and test application in QEMU using the `qemu-run`
 make target:
+
 ```
 make qemu-run
 ```
+
 Alternatively, if you don't want QEMU to show a window with the video
 output, or if you are on a machine without graphics capabilities, use
 the `qemu-run-no-display` target instead. The kernel logs to the serial
 port, which QEMU redirects to standard output.
+
 ```
 make qemu-run-no-display
 ```
 
+In either case, this generates a log file called `run-jinue.log` in
+`devel/qemu/` with the full kernel and test application output.
+
+Finally, you can run the kernel and test application, and then run a
+script that performs checks on the log file by using the `qemu-check`
+make target:
+
+```
+make qemu-check
+```
+
 How to Install
 --------------
 
 If you will not be using QEMU for testing, you can copy the kernel image
 to `/boot` by running the following:
+
 ```
 sudo make install
 ```
-The file name and path of the installed kernel image file is
+
+The full file path of the kernel image installed in this way is
 `/boot/jinue`.
 
 Optionally, if you will not be providing your own initial RAM disk file,
 you can install the test application initial RAM disk to `/boot` as
 well.
+
 ```
 sudo make install-testapp
 ```
-The file name and path of the installed RAM disk file is
+
+The full file path of the installed RAM disk file is
 `/boot/jinue-testapp-initrd.tar.gz`.
 
 Once this is done, you need to configure your boot loader/manager to
-load this kernel. Jinue uses the 16-bit Linux boot protocol, so you can
-configure your boot manager as if you were loading a Linux image with
-the 16-bit boot protocol
-([linux16 command](devel/virtualbox/grub.cfg#L29) if using GRUB).
+load the installed kernel. Jinue uses the (32-bit or 16-bit) Linux x86
+boot protocol, so you can configure your boot manager as if you were
+loading a Linux image. This is system dependent but, with GRUB, the
+configuration entry might look something like this:
+
+```
+menuentry 'Jinue (32-bit boot protocol, test app)' {
+    # Replace with the appropriate GRUB module for your filesystem.
+	insmod ext2
+    # Replace with the partition where you installed Jinue.
+	set root='hd0,msdos7'
+	set gfxpayload='text'
+	echo 'Loading Jinue microkernel...'
+    # See command line documentation for details on the command line options.
+	linux /boot/jinue vga_enable=yes serial_enable=no DEBUG_DUMP_MEMORY_MAP=1 DEBUG_DUMP_SYSCALL_IMPLEMENTATION=1 DEBUG_DUMP_RAMDISK=1 RUN_TEST_IPC=1
+	echo 'Loading test application initial RAM disk...'
+	initrd /boot/jinue-testapp-initrd.tar.gz
+}
+```
+
+For detail on the command line options, see the [command line
+documentation](doc/cmdline.md).
 
 For detail on the Linux boot protocol, see
 [Documentation/x86/boot.rst](https://www.kernel.org/doc/Documentation/x86/boot.rst)
@@ -127,5 +178,6 @@ in the Linux source tree.
 Documentation
 -------------
 
-There is some documentation in the [doc/ directory](doc/README.md). It
-is still very much a work in progress.
+There is some documentation in the `doc/` directory]. It is still a work
+in progress and some of it is not up to date. The [documentation file
+README](doc/README.md) links to the parts that are up to date.