On Sat, Nov 3, 2012 at 8:26 AM, Wolfgang Denk <w...@denx.de> wrote: > Dear Simon Glass, > > In message <1351902453-27956-16-git-send-email-...@chromium.org> you > wrote: > > From: Vadim Bendebury <vben...@chromium.org> > > > > Provide u-boot console functions to access IO space registers. A no > > thrills implementation, accessing one register at a time. > > > > For example: > > boot > iod 80 > > 0080: 00000094 > > boot > iod.w 80 > > 0080: 0094 > > boot > iod.b 80 > > 0080: 94 > > boot > iow.b 0x80 12 > > boot > iod 0x80 > > 0080: 00000012 > > What are the exact use cases where this is necessary, i. e. where > plain md / mw does not work? > > Wolfgang,
the x86 architecture defines this different kind of address space, device IO, in addition to memory address space. This is a remnant of the days when address lines were sparse. On typical x86 systems devices are accessed through this device IO space, and this patch adds a command which allows the operator to read and write device registers on such systems. Cheers, /vb Best regards, > > Wolfgang Denk > > -- > DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de > Quantum particles: The dreams that stuff is made of. > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot >
_______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot