1、将目录切换置gem5欲安装的目录
2、在目录wyj@arch-node3:~$下输入
hg clone http://repo.gem5.org/gem5接下来会看到gem5的更新
destination directory: gem5 requesting all changes adding changesets adding manifests adding file changes added 10014 changesets with 59050 changes to 6786 files updating to branch default 3310 files updated, 0 files merged, 0 files removed, 0 files unresolved
3、进入gem5目录：
cd gem5
4、在gem5目录下输入：
hg tags可以看到gem5的所有版本，其版本如下：
tip 10013:2e9e2fb2fa71 stable_2013_10_14 9804:6a043adb1e8d stable_2013_06_16 9644:07352f119e48 stable_2012_06_28 9073:f75ee4849c40 stable_2012_02_02 8642:549b72de8f72 Calvin_Submission 6859:5de565c4b7bd m5_2.0_beta6 5588:d8b246a665c1 copyright_update 5404:60a931b03fb1 m5_2.0_beta5 5371:dce5a8655829 m5_2.0_beta4 5214:1ac44b6c87ec m5_2.0_beta3 4464:91a9ac67662a m5_2.0_beta2 3708:b174ae14f007 m5_2.0_beta1_patch1 3078:d83885ad2b41 m5_2.0_beta1 3041:8d690c7c2efc m5_1.1 1906:cdd48642d9bf m5_1.0_web 1785:ffe1942d845c m5_1.0_tutorial 1780:4cfa92eca35d m5_1.0_beta2 758:069849384988 m5_1.0_beta1 131:1a40e60270c15、选择你要更新的版本，假若我要更新版本stable_2012_02_02，我只需输入：
hg update stable_2012_02_02
则会把gem5更新成2012_02_02发布的版本。如果要更新成其他版本，操作类似