From 506858f996f8094ad79f01615c3647f254381a47 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <nathan@kernel.org>
Date: Wed, 27 Jan 2021 11:39:43 -0700
Subject: [PATCH] boot-utils: Add '--use-cbl-qemu'

We need to do this in order to boot s390 kernels in our CI. The qemu
binaries are hosted in a separate repo to keep things reasonable in
terms of file size.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 .gitignore   |  1 +
 README.txt   |  7 +++++++
 boot-qemu.sh | 16 ++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/.gitignore b/.gitignore
index bc78feb..e7df6b3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
+qemu-binaries/
 rootfs.cpio
diff --git a/README.txt b/README.txt
index a9978ea..9960c20 100644
--- a/README.txt
+++ b/README.txt
@@ -49,3 +49,10 @@ Optional parameters:
     QEMU machine. Depending on the power of the host machine, this might
     not be long enough for a kernel to boot so this allows that timeout
     to be configured. Takes the value passed to timeout (e.g. 30s or 4m).
+
+  --use-cbl-qemu (only relevant with '-a s390'):
+    Currently, s390 only boots with patches that are available in QEMU
+    master. It could take a while for those patches to make it to various
+    distribution versions of qemu-system-s390 so we provide a copy of it
+    at https://github.com/ClangBuiltLinux/qemu-binaries. This option
+    downloads that repo here and decompresses the binary to use it.
diff --git a/boot-qemu.sh b/boot-qemu.sh
index c32732a..6ece571 100755
--- a/boot-qemu.sh
+++ b/boot-qemu.sh
@@ -72,6 +72,10 @@ function parse_parameters() {
                 shift && TIMEOUT=${1}
                 ;;
 
+            --use-cbl-qemu)
+                USE_CBL_QEMU=true
+                ;;
+
             *)
                 die "Invalid parameter '${1}'"
                 ;;
@@ -208,6 +212,18 @@ function setup_qemu_args() {
             KIMAGE=bzImage
             QEMU_ARCH_ARGS=(-M s390-ccw-virtio)
             QEMU=(qemu-system-s390x)
+            if ${USE_CBL_QEMU:-false}; then
+                QEMU_BINARIES=${BASE}/qemu-binaries
+
+                green "Downloading or updating qemu-binaries..."
+                [[ -d ${QEMU_BINARIES} ]] || git clone https://github.com/ClangBuiltLinux/qemu-binaries "${QEMU_BINARIES}"
+                git -C "${QEMU_BINARIES}" pull --rebase
+
+                QEMU_BIN=${QEMU_BINARIES}/bin
+                QEMU_S390=${QEMU_BIN}/${QEMU[*]}
+                zstd -q -d "${QEMU_S390}".zst -o "${QEMU_S390}" || die "Error decompressing qemu-system-s390x"
+                export PATH=${QEMU_BIN}:${PATH}
+            fi
             ;;
 
         x86 | x86_64)