builder/qemu: use 512M for -m [GH-1444]

CHANGELOG.md

@@ -27,6 +27,7 @@ BUG FIXES:
   * builder/parallels/all: Add support for Parallels Desktop 10 [GH-1438]
   * builder/parallels/all: Added some navigation keys [GH-1442]
   * builder/qemu: If headless, sdl display won't be used. [GH-1395]
+  * builder/qemu: Use `512M` as `-m` default. [GH-1444]
   * builder/virtualbox/all: Seed RNG to avoid same ports. [GH-1386]
   * builder/vmware/all: `ssh_host` accepts templates. [GH-1396]
   * builder/vmware/all: Don't remount floppy in VMX post step. [GH-1239]

builder/qemu/step_run.go

@@ -83,7 +83,7 @@ func getCommandArgs(bootDrive string, state multistep.StateBag) ([]string, error
 	defaultArgs["-drive"] = fmt.Sprintf("file=%s,if=%s", imgPath, config.DiskInterface)
 	defaultArgs["-cdrom"] = isoPath
 	defaultArgs["-boot"] = bootDrive
-	defaultArgs["-m"] = "512m"
+	defaultArgs["-m"] = "512M"
 	defaultArgs["-redir"] = fmt.Sprintf("tcp:%v::22", sshHostPort)
 	defaultArgs["-vnc"] = vnc