From mboxrd@z Thu Jan 1 00:00:00 1970 From: tike64 at gmail.com Date: Mon, 15 Dec 2008 08:53:13 +0200 Subject: [U-Boot] question about TEXT_BASE in U-boot In-Reply-To: <1229255632.32640.10.camel@wangrui-laptop> References: <248c3fc70812140214w248833cau8a1bc48944409eeb@mail.gmail.com> <5ad5c5a40812140226h642b11cal934e3dd398001276@mail.gmail.com> <1229255632.32640.10.camel@wangrui-laptop> Message-ID: <4945FED9.60205@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de wangrui wrote: > After power up board, CPU will execute the instruction store at 0x0 (ROM > flash), and I download u-boot > to ROM flash (start from 0x0) so that the instruction store at 0x0 is > "a0f00000: ea000014 b a0f00058 " > > Then program will jump to 0xa0f00058 (SDRAM)... No, it does not. b is a relative branch and causes a jump to 0xa0f00058 only if you execute it at 0xa0f00000. You would make yourself a big favor by familiarizing yourself with ARM instruction set. -- Timo