Hi Bhupesh, On Fri, Sep 18, 2015 at 02:03:10PM +0000, Sharma Bhupesh wrote: > I have been trying my hands-on on replacing the current Legacy BDS > loader with the EFI_STUB on a Freescale ARM64 SoC to load Linux and > utilize the features of the EFI_STUB. > > I am taking a reference from ARM juno support, where I am getting > confused about a couple of points: > > 1. Legacy Linux Loader: > > I see the following INF inclusion in 'ArmPlatformPkg.dsc'. What do > we mean exactly by Legacy Linux Loader here? Is it the built-in > Linux Loader which ignores the stub (as you refer to it, in a HiKey > related discussion: > https://lists.96boards.org/pipermail/dev/2015-March/000083.html) > > ArmPlatformPkg.dsc > ---------------------- > # Legacy Linux Loader > ArmPkg/Application/LinuxLoader/LinuxLoader.inf
Yes, this is the anti-UEFI. > 2. Passing a initramfs/initird to the kernel: > > Using the reference from Juno board, I have added the following to > my .dsc. This allows me to specify a ARM64 Image + DTB placed on NOR > flash to the kernel and I see that using the BootMenu, I can boot > the kernel partially with the same: > > gArmPlatformTokenSpaceGuid.PcdDefaultBootDescription|L"EFI Linux from NOR > flash" > > gArmPlatformTokenSpaceGuid.PcdDefaultBootDevicePath|L"MemoryMapped(0x0,0x61100000,0x62000000)/Image" > > gEmbeddedTokenSpaceGuid.PcdFdtDevicePaths|L"MemoryMapped(0x0,0x63000000,0x638FFFFF)/fsl-dtb.dtb" > gArmPlatformTokenSpaceGuid.PcdDefaultBootArgument|"console=ttyS0,115200 > root=/dev/ram0 earlycon=uart8250,0x21c0500,115200" > > However, I cannot find a way to provide a .cpio based > initramfs/initrd kept on the NOR flash to the kernel. > > Will I need to use other booting media like a SD card (rather than > the NOR flash) and keep the Root-file-system there and invoke all > the components via a "startup.nsh" like script: > > fs0:\Image dtb=fsl-dtb.dtb rootwait console=ttyS0,115200 root=/dev/ram0 > earlycon=uart8250,0x21c0500,115200 root=/dev/sda1 Well, first of all, you should not be supplying a dtb via the command line (if you enabled Secure Boot, it would just be ignored anyway); you should register it as a configuration table. Secondly, specifying console= on the command line is redundant these days - just add a stdout-path entry to your dtb's chosen node. Similarly for the earlycon - just "earlycon" is sufficient if you have a stdout-path. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/chosen.txt Thirdly, if you're happy with the hardcoding, you could just create your own linux,initrd-start (inclusive) and linux,initrd-end (exclusive) entries in chosen. At which point root=/dev/ram should be redundant, and you would end up with arguments: earlycon root=/dev/sda1 Regards, Leif > Here are my Linux boot logs: > > Logs: > ------ > > [1] EFI Linux from NOR flash > - MemoryMapped(0x0,0x61100000,0x62000000)/Image > - Arguments: console=ttyS0,115200 root=/dev/ram0 > earlycon=uart8250,0x21c0500,115200 > [2] Shell > [3] Boot Manager > Start: 1 > EFI stub: Booting Linux Kernel... > EFI stub: Using DTB from configuration table > Booting Linux on physical CPU 0x0 > Initializing cgroup subsys cpu > Linux version 3.19.3+ ..... > > Regards, > Bhupesh _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
