Hi, On Thu, Nov 22, 2018 at 05:27:49PM +0800, lzSun wrote: > Hello ,Genode Community > I have written an email before which has a similar question to this email, > but I haven't receive any response yet. Because solving this problem is very > important to my work , so I decide to put it out again and hope to receive > some help. > The thing is I want to use sd_card driver in i.mx53 quick start board with > trustzone. I know Martin said " you should not run 'sd_card' with Genodes > Trustzone feature-set (platform 'hw_imx53_qsb_tz'), because Genode will then > declare the ESDHC-IRQ to be unsecure to enable Linux to drive SD cards."[1]. > But unfortunately, my work is just needs to use sd_card driver with > trustzone. So I wonder is this possible? I am now using the latest Genode > version(18.08). > Form my point of view, if ESDHC-IRQ is still to be unsecure, this's two ways > to solve this problem: > 1. set ESDHC-IRQ to be secure. In this way ,Genode OS in secure world can > directly drive the SD card. Also, the linux in the normal world must be > modified to the stat that could not drive SD card. If this is right, could > you provide me some hint to this method?
Surely this is the right way to go. All ingredients are already in place. Have a look at the usb_armory platform, which uses exactly the same SoC i.MX53 with a trustzone Linux using the sd-card client-wise from the Genode secure-world. You need to change the sd-card device assignment in: `repos/base-hw/src/bootstrap/spec/imx53_qsb/platform_trustzone.cc` The fourth parameter of the Csu object decides over the sd-card assignment. And of course you need to change the Linux kernel to use the paravirtualized block device of the trustzone VMM. Please use the Linux kernel version + adaptations from here as inspiration: https://github.com/m-stein/linux/tree/genode_hw_usb_armory_tz_vmm > 2. forward the sd card request to linux in the normal world.So all the sd > card operation will be performed by linux. However, I think this will > introduce more world switch between two worlds and you should provide a linux > driver to serve for Genode's file operation. > I will be grateful if you could give me some help, thanks a lot! > I cannot see a reason for using a secure-world stack than anyway. If make the secure side dependent of the potential insecure side is no good idea for obvious reasons. Best regards Stefan > > > > ------------------ > Best wishes > _______________________________________________ > Genode users mailing list > [email protected] > https://lists.genode.org/listinfo/users -- Stefan Kalkowski Genode labs https://github.com.skalk | https://genode.org _______________________________________________ Genode users mailing list [email protected] https://lists.genode.org/listinfo/users
