From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?GB2312?B?zNq3ycH6?= Date: Wed, 28 Dec 2005 17:33:48 +0800 Subject: [U-Boot-Users] How is the "ba 0xfff80000" located at 0xfffffffc ? Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de As in Embedded Planet EP405 board, ppc405GPr processor support high boot only, when Power On or reset, the processor starts at 0xfffffffc and the code is executed from flash/rom. There is usually a branch instruction(such as: ba target) in 0xfffffffc so that it can jump to the target. For example, if i set TEXT_BASE=0xfff80000 in u-boot,it means the instruction "ba 0xfff80000" is in 0xfffffffc. My questions are follow: 1 where can i find the branch instruction "ba 0xfff80000" in u-boot-1.1.3 code? it seems it is not in start.s 2 As we know, before u-boot is written to flash the first time, there is nothing in flash. when we write u-boot in flash from addr 0xfff80000, how is the branch instruction written to addr 0xfffffffc which is not neigbour to u-boot code body? Thank you and best wishes!