platform: add the aarch64_iot platform

This platform copies more files into `/boot` which are necessary to be
able to boot IoT on some single board computers.

We also immediately set this on the `Aarch64_IoT` platform which needs
u-boot to be placed in the `/boot`.

This closes #3312.

internal/platform/aarch64.go

@@ -27,3 +27,36 @@ func (p *Aarch64) GetPackages() []string {
 
 	return packages
 }
+
+type Aarch64_IoT struct {
+	BasePlatform
+	UEFIVendor string
+	BootFiles  [][2]string
+}
+
+func (p *Aarch64_IoT) GetArch() Arch {
+	return ARCH_AARCH64
+}
+
+func (p *Aarch64_IoT) GetUEFIVendor() string {
+	return p.UEFIVendor
+}
+
+func (p *Aarch64_IoT) GetPackages() []string {
+	packages := p.BasePlatform.FirmwarePackages
+
+	if p.UEFIVendor != "" {
+		packages = append(packages,
+			"dracut-config-generic",
+			"efibootmgr",
+			"grub2-efi-aa64",
+			"grub2-tools",
+			"shim-aa64")
+	}
+
+	return packages
+}
+
+func (p *Aarch64_IoT) GetBootFiles() [][2]string {
+	return p.BootFiles
+}

internal/platform/platform.go

@@ -63,6 +63,7 @@ type Platform interface {
 	GetZiplSupport() bool
 	GetPackages() []string
 	GetBuildPackages() []string
+	GetBootFiles() [][2]string
 }
 
 type BasePlatform struct {
@@ -98,3 +99,7 @@ func (p BasePlatform) GetPackages() []string {
 func (p BasePlatform) GetBuildPackages() []string {
 	return []string{}
 }
+
+func (p BasePlatform) GetBootFiles() [][2]string {
+	return [][2]string{}
+}