Hi Anup, On Mon, Jan 21, 2019 at 12:04 PM Anup Patel <anup.pa...@wdc.com> wrote: > > > > > -----Original Message----- > > From: Atish Patra [mailto:atish.pa...@wdc.com] > > Sent: Monday, January 21, 2019 7:07 AM > > To: Auer, Lukas <lukas.a...@aisec.fraunhofer.de>; s...@chromium.org; > > bmeng...@gmail.com; r...@andestech.com; Anup Patel > > <anup.pa...@wdc.com>; joe.hershber...@ni.com; > > yamada.masah...@socionext.com > > Cc: paul.walms...@sifive.com; pal...@sifive.com; h...@infradead.org; u- > > b...@lists.denx.de; ag...@suse.de > > Subject: Re: [PATCH v2 00/11] SiFive FU540 Support > > > > On 1/20/19 12:34 PM, Auer, Lukas wrote: > > > Hi Anup, > > > > > > On Fri, 2019-01-18 at 11:18 +0000, Anup Patel wrote: > > >> This patchset adds SiFive Freedom Unleashed (FU540) support to RISC-V > > >> U-Boot. > > >> > > >> The patches are based upon latest RISC-V U-Boot tree > > >> (git://git.denx.de/u-boot-riscv.git) at commit id > > >> 91882c472d8c0aef4db699d3f2de55bf43d4ae4b > > >> > > >> All drivers namely: SiFive PRCI, SiFive Serial, and Cadance MACB > > >> Ethernet work fine on actual SiFive Unleashed board and QEMU sifive_u > > >> machine. > > >> > > > > > > Thanks for working on this! Are you also planning on adding the > > > features of the FSBL to U-Boot to remove it from the boot flow? > > > > > > > That would also mean that adding M-mode capability in U-boot. As of now > > the expected boot flow is > > > > ZSBL->FSBL------->BBL/OpenSBI--------->U-boot------------->Linux > > (M mode from ROM) (M mode from DRAM) (S Mode from DRAM) (S Mode > > from > > DRAM) > > > > This is not the mandated boot flow but running the last stage boot loader > > from S-mode gives flexibility in virtualization in future. > > To elaborate more on what Atish already mentioned, our rationale behind > ZSBL->FSBL->BBL/OpenSBI->U-Boot(or Any other general bootloader) is > as follows: > 1. We don't want to replicate FSBL code (DRAM and other system-level init) > in general purpose bootloaders (U-Boot, UEFI/Tianocore, etc) > 2. We don't want to replicate SBI runtime implementation in general > purpose bootloaders (U-Boot, UEFI/Tianocore, etc) > 3. We want to use general purpose bootloader (U-Boot, UEFI/Tianocore, etc) > inside Guest/VM (S-mode) > > Of course, above boot flow is not mandatory. There could be RISC-V systems > where prior booting stages (such as ZSBL and FSBL) don't exist so users have > following options: > 1. Run U-Boot in M-mode for such RISC-V systems and link to OpenSBI static > library for SBI runtime services > 2. Run U-Boot in S-mode but do most system-level initialization (including > DRAM init) in OpenSBI firmware. In other words, use following booting flow: > OpenSBI (M-mode) -> U-Boot (S-mode) > > For point1 above, we will first try it with U-Boot M-mode on QEMU Virt > machine.
Has the OpenSBI project be started somewhere? Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
