linux: Add a linux on QEMU tutorial

Author: stffrdhrn

README.md

@@ -10,7 +10,7 @@ developing software and SoC's using the OpenRISC cpu architecture.
 We are currently in progress working on a new structure
 and the intended outline is:
 
- - Intro - OK
+ - [Intro](https://openrisc.io/tutorials/) - OK
    - Programmers Guide - Link to architecture spec, etc.
    - Getting EDA tools, quartus, vivado
 
@@ -49,12 +49,12 @@ and the intended outline is:
     - Tutorials
       - [linux on or1ksim](https://openrisc.io/tutorials/docs/linux-on-or1ksim.html) - OK
         - defconfig + busybox
-      - Linux on QEMU *TODO*
+      - [linux on QEMU](https://openrisc.io/tutorials/docs/linux-on-qemu.html) - OK
         - virt_defconfig + buildroot
-      - Running linux on Litex SoC *TOD*
+      - Running linux on Litex SoC *TODO*
         - SIM + litex_defconfig + buildroot
         - arty + litex_defconfig + buildroot
-      -  Running Linux on fusesoc SoC *TODP*
+      -  Running Linux on fusesoc SoC *TODO*
         - SIM + defconfig + busybox
         - de0_nano + defconfig + busybox
         - de0_nano-multicore + smp_defconfig + busybox

docs/linux-on-or1ksim.md

@@ -109,9 +109,9 @@ requires rebuilding the kernel.
 To start Linux on `or1ksim` we run `or1k-elf-sim` passing the kernel as an argument.
 This will:
 
- # Initialize the OpenRISC simulator
- # Load the kernel image, including the embedded rootfs, into RAM memory
- # Reset the simulator CPU to PC 0x100 kicking off the kernel boot process
+ 1. Initialize the OpenRISC simulator
+ 2. Load the kernel image, including the embedded rootfs, into RAM memory
+ 3. Reset the simulator CPU to PC 0x100 kicking off the kernel boot process
 
 The `or1ksim` starts a console on port `10084` which we can connect to to access
 the system.
@@ -141,6 +141,8 @@ To add your own programs to the rootfs you can use the [musl](https://musl.libc.
 toolchain to build executables as follows:
 
 ```
+curl -L -O https://openrisc.io/tutorials/sw/hello/hello.c
+
 or1k-none-linux-musl-gcc hello.c -o busybox-small-rootfs-20250708/initramfs/hello
 ```