Running busybear linux on recent qemu

Makefile

@@ -1,7 +1,7 @@
 all: busybear.bin
 
 clean:
-	rm -fr build busybear.bin
+	rm -fr build busybear-riscv64.bin busybear-riscv32.bin
 
 distclean: clean
 	rm -fr archives

README.md

@@ -1,3 +1,39 @@
+# Short introduction note to this particular fork
+
+Busybear Linux is the work of Michael J. Clark, this fork is used for
+providing a simple linux set-up on risc-v for tearching or research
+works in my group.
+It was in particular used to check QEMU scalability with and without
+pinning, and the disk may include a version of the parsec benchmarks.
+
+We update to new versions of the kernel and busybox once on a while,
+usually when we need to do new stuffs.
+
+We also added the possibility to build a 32-bit kernel.
+Default is to compile for riscv64, change comments in `config/busybear.config`
+to compile for riscv32.
+This allows to check that we do not break too many things when hacking in
+QEMU.
+
+Note that _this is meant to be compiled with a home made cross-dev
+toolchain_, as there are sysroot dependencies that some distros do not
+provide, TTBOMK.
+The symptom is that boot fails while launching `/sbin/init`.
+
+Also, you cannot compile the 32 and 64 bit versions at the same time, however
+the generated files are in different directories or have different names at the
+end, so you can have both systems sitting on your machine at the same time after
+compilation.
+
+Typical command-lines:
+```
+../qemu-vp/build-rtan/qemu-system-riscv32 -nographic -kernel build/linux-5.15.32-riscv32/arch/riscv/boot/Image -machine virt -append "root=/dev/vda ro console=ttyS0 debug" -drive file=busybear-riscv32.bin,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -accel tcg,thread=multi -smp 128
+```
+and
+```
+../qemu-vp/build-rtan/qemu-system-riscv64 -nographic -kernel build/linux-5.15.32-riscv64/arch/riscv/boot/Image -machine virt -append "root=/dev/vda ro console=ttyS0 debug" -drive file=busybear-riscv64.bin,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -accel tcg,thread=multi -smp 32
+```
+
 # busybear-linux
 
 busybear-linux is a tiny RISC-V Linux root filesystem image that targets
@@ -80,7 +116,7 @@ to be run in Linux, even if preparing a root filesystem image for macOS.
 ### busybear-linux
 
 ```
-git clone --recursive https://github.com/michaeljclark/busybear-linux.git
+git clone --recursive https://github.com/fpetrot/busybear-linux.git
 cd busybear-linux
 make
 ```
@@ -137,7 +173,7 @@ The following command starts busybear-linux:
 which runs executes this command:
 
 ```
-sudo qemu-system-riscv64 -nographic -machine virt \
+sudo qemu-system-riscv64 -nographic -machine virt -bios none \
   -kernel bbl -append "root=/dev/vda ro console=ttyS0" \
   -drive file=busybear.bin,format=raw,id=hd0 \
   -device virtio-blk-device,drive=hd0 \

conf/busybear.config

@@ -1,11 +1,17 @@
-BUSYBOX_VERSION=1.30.1
-DROPBEAR_VERSION=2018.76
-LINUX_KERNEL_VERSION=5.0
+BUSYBOX_VERSION=1.36.1
+DROPBEAR_VERSION=2022.82
+LINUX_KERNEL_VERSION=6.9.8
 
+# Uncomment to build 64-bit version
 ARCH=riscv64
 ABI=lp64d
 CROSS_COMPILE=riscv64-unknown-linux-gnu-
 
-IMAGE_FILE=busybear.bin
-IMAGE_SIZE=100
+# Uncomment to build 32-bit version
+# ARCH=riscv32
+# ABI=ilp32d
+# CROSS_COMPILE=riscv32-unknown-linux-gnu-
+
+IMAGE_FILE=busybear-${ARCH}.bin
+IMAGE_SIZE=1024
 ROOT_PASSWORD=busybear