说明：  U-Boot不仅仅支持嵌入式Linux系统的引导，它还支持NetBS D, VxWorks, QNX, RTEMS, ARTOS, LynxOS, android嵌入式操作系统。其目前要支持的目标操作系统是OpenBSD, NetBSD, FreeBSD,4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, LynxOS, pSOS, QNX, RTEMS, ARTOS, android。这是U-Boot中Universal的一层含义，另外一层含义则是U-Boot除了支持PowerPC系列的处理器外，还能支持MIPS、 x86、ARM、NIOS、XScale等诸多常用系列的处理器。这两个特点正是U-Boot项目的开发目标，即支持尽可能多的嵌入式处理器和嵌入式操作系统。就目前来看，U-Boot对PowerPC系列处理器支持最为丰富，对Linux的支持最完善。其它系列的处理器和操作系统基本是在2002年11 月PPCBOOT改名为U-Boot后逐步扩充的。从PPCBOOT向U-Boot的顺利过渡，很大程度上归功于U-Boot的维护人德国DENX软件工程中心Wolfgang Denk[以下简称W.D]本人精湛专业水平和执着不懈的努力。
(U-boot not only supports the boot of embedded Linux system, but also supports netbs D. VxWorks, QNX, RTEMS, Artos, lynxos, Android embedded operating system. The current target operating systems to be supported are OpenBSD, NetBSD, FreeBSD, 4.4BSD, Linux, SVR4, ESIX, Solaris, IRIX, SCO, Dell, NCR, VxWorks, lynxos, PSOs, QNX, RTEMS, Artos, Android. This is the meaning of universal in u-boot. The other meaning is that u-boot supports not only PowerPC series processors, but also MIPs, x86, arm, NIOS, Xscale and many other commonly used series processors. These two characteristics are exactly the development goal of the u-boot project, that is to support as many embedded processors and embedded operating systems as possible. At present, u-boot has the richest support for PowerPC series processors and the most perfect support for Linux.)