pkg/build: Add ppc64le Linux as a supported configuration

Enable the Linux builder for ppc64le.

For ppc64le, we use zImage rather than bzImage as our kernel target. Pass
through the target architecture to buildKernel() so we can pick the right
target based on arch.

Closes: #1084 ("pkg/build: Support building Linux on ppc64le")
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>

2 files changed, 24 insertions, 6 deletions

diff --git a/pkg/build/build.go b/pkg/build/build.go
index 8ccbe9e3d..7e2a71ae4 100644
--- a/pkg/build/build.go
+++ b/pkg/build/build.go
@@ -72,6 +72,7 @@ func getBuilder(targetOS, targetArch, vmType string) (builder, error) {
 	}{
 		{"linux", "amd64", []string{"gvisor"}, gvisor{}},
 		{"linux", "amd64", []string{"gce", "qemu"}, linux{}},
+		{"linux", "ppc64le", []string{"qemu"}, linux{}},
 		{"fuchsia", "amd64", []string{"qemu"}, fuchsia{}},
 		{"fuchsia", "arm64", []string{"qemu"}, fuchsia{}},
 		{"akaros", "amd64", []string{"qemu"}, akaros{}},
diff --git a/pkg/build/linux.go b/pkg/build/linux.go
index e3c8a6d9f..c56595743 100644
--- a/pkg/build/linux.go
+++ b/pkg/build/linux.go
@@ -25,7 +25,7 @@ type linux struct{}
 
 func (linux linux) build(targetArch, vmType, kernelDir, outputDir, compiler, userspaceDir,
 	cmdlineFile, sysctlFile string, config []byte) error {
-	if err := linux.buildKernel(kernelDir, outputDir, compiler, config); err != nil {
+	if err := linux.buildKernel(targetArch, kernelDir, outputDir, compiler, config); err != nil {
 		return err
 	}
 	if err := linux.createImage(targetArch, vmType, kernelDir, outputDir, userspaceDir, cmdlineFile,
@@ -35,7 +35,7 @@ func (linux linux) build(targetArch, vmType, kernelDir, outputDir, compiler, use
 	return nil
 }
 
-func (linux) buildKernel(kernelDir, outputDir, compiler string, config []byte) error {
+func (linux) buildKernel(targetArch, kernelDir, outputDir, compiler string, config []byte) error {
 	configFile := filepath.Join(kernelDir, ".config")
 	if err := osutil.WriteFile(configFile, config); err != nil {
 		return fmt.Errorf("failed to write config file: %v", err)
@@ -59,9 +59,18 @@ func (linux) buildKernel(kernelDir, outputDir, compiler string, config []byte) e
 	if err := osutil.CopyFile(configFile, outputConfig); err != nil {
 		return err
 	}
-	// We build only bzImage as we currently don't use modules.
+	// We build only zImage/bzImage as we currently don't use modules.
 	cpu := strconv.Itoa(runtime.NumCPU())
-	cmd = osutil.Command("make", "bzImage", "-j", cpu, "CC="+compiler)
+
+	var target string
+	switch targetArch {
+	case "386", "amd64":
+		target = "bzImage"
+	case "ppc64le":
+		target = "zImage"
+	}
+	cmd = osutil.Command("make", target, "-j", cpu, "CC="+compiler)
+
 	if err := osutil.Sandbox(cmd, true, true); err != nil {
 		return err
 	}
@@ -87,8 +96,16 @@ func (linux) createImage(targetArch, vmType, kernelDir, outputDir, userspaceDir,
 	if err := osutil.WriteExecFile(scriptFile, []byte(createImageScript)); err != nil {
 		return fmt.Errorf("failed to write script file: %v", err)
 	}
-	bzImage := filepath.Join(kernelDir, filepath.FromSlash("arch/x86/boot/bzImage"))
-	cmd := osutil.Command(scriptFile, userspaceDir, bzImage, targetArch)
+
+	var kernelImage string
+	switch targetArch {
+	case "386", "amd64":
+		kernelImage = "arch/x86/boot/bzImage"
+	case "ppc64le":
+		kernelImage = "arch/powerpc/boot/zImage.pseries"
+	}
+	kernelImagePath := filepath.Join(kernelDir, filepath.FromSlash(kernelImage))
+	cmd := osutil.Command(scriptFile, userspaceDir, kernelImagePath, targetArch)
 	cmd.Dir = tempDir
 	cmd.Env = append([]string{}, os.Environ()...)
 	cmd.Env = append(cmd.Env,