From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Date: Mon, 10 Nov 2014 14:25:52 +0100 Subject: [U-Boot] ARM: PSCI 0.1 vs 0.2 In-Reply-To: <5460B8E8.9070706@arm.com> References: <5460B4B5.2060602@siemens.com> <5460B8E8.9070706@arm.com> Message-ID: <5460BCE0.2020301@siemens.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 2014-11-10 14:08, Marc Zyngier wrote: > On 10/11/14 12:51, Jan Kiszka wrote: >> Hi Marc, >> >> what is the motivation to expose a PSCI 0.1 interface in U-boot, instead >> of 0.2? Support for preexisting users of 0.1? The kernel seems to be >> happy with both, and I'm now wondering if we should actually add the >> legacy version to Jailhouse as well (I hope we can avoid this). > > The initial rational was simple: at the time this code was written, the > 0.2 spec still in review, and nobody was implementing it. Supporting 0.1 > was the only viable use-case. > >> Still studying the logic: Is it possible to provide both interfaces, and >> would it make sense? > > Supporting both is very easy. Just output the 0.2 function numbers that > actually make sense for 0.1 and have both compatible strings. Ah, cool - parameters and return values of, say, CPU_ON/OFF are compatible across both versions? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux