On 29 December 2013 19:10, <tiger...@viatech.com.cn> wrote: > Hi, Dall: > I have a few questions about switching cpu's state from secure to > non-sec in uboot. > 1. I found do_nonsec_virt_switch() function had been integrated in > uboot_2014_01_RC2. > This function would switch cpu from secure state to non-sec, even > into hyp-state. > So, my question is: > If a SOC is based on ARMv7 architecture: > Virt-v7.c / nonsec_virt.S are common files to all kinds of SOCs > which are produced by different Vendors?
Yes, the aim is to be able to reuse as much of this code for as many platforms as possible. > > 2. Does uboot need to switch its state to non-sec? > Based on ARM company released doc: > U-boot should run at non-sec state, so no need to swith to non-sec > again. > It depends on the board. Which ARM doc are you referring to? In general, there are three options for how u-boot is booted: 1. In secure mode 2. In non-secure hyp mode 3. in non-secure svc mode for (1) you can just switch to non-secure hyp. for (2) you don't have to do anything. for (3) you're screwed, unless there's a backdoor call to enter Hyp mode (typically found on TI hardware). If we are talking PSCI, that's a different story, and if that's provided by the board and not U-boot (see Marc's recent work), then I would expect that board to always boot U-boot in Hyp mode to be coherent with the documentation. -Christoffer _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
