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Diffstat (limited to 'Documentation/boards/riscv.rst')
| -rw-r--r-- | Documentation/boards/riscv.rst | 114 |
1 files changed, 108 insertions, 6 deletions
diff --git a/Documentation/boards/riscv.rst b/Documentation/boards/riscv.rst index 97f4d1deb7..990bd16a64 100644 --- a/Documentation/boards/riscv.rst +++ b/Documentation/boards/riscv.rst @@ -6,10 +6,10 @@ QEMU Virt barebox supports both the qemu riscv32 and riscv64 ``-M virt`` boards:: - make ARCH=riscv virt64_defconfig + make ARCH=riscv rv64i_defconfig qemu-system-riscv64 -M virt -serial stdio -kernel build/images/barebox-dt-2nd.img -Replace ``64`` by ``32`` for 32-bit build. :ref:`virtio_sect` over MMIO is supported and +For 32-bit builds use ``virt32_defconfig``. :ref:`virtio_sect` over MMIO is supported and can be used for e.g. an extra console or to pass in a virtio-blk device:: qemu-system-riscv64 -M virt -serial stdio \ @@ -58,14 +58,14 @@ To activate add:: into the config file. -See https://barebox.org/jsbarebox/?graphic=1 for a live example. +See https://barebox.org/demo/?graphic=1 for a live example. BeagleV ------- barebox has second-stage support for the BeagleV Starlight:: - make ARCH=riscv starfive_defconfig + make ARCH=riscv rv64i_defconfig make Thie resulting ``./images/barebox-beaglev-starlight.img`` can be used as payload @@ -168,13 +168,13 @@ Connect to board's UART with your favorite serial communication software (e.g. minicom) and check 'nmon> ' prompt (nmon runs from onchip ROM). Next close your communication software and use ./scripts/nmon-loader -to load barebox image into board's DRAM, e.g. +to load barebox image into board's DRAM, e.g.:: # ./scripts/nmon-loader barebox.erizo.nmon /dev/ttyUSB0 115200 Wait several munutes for 'nmon> ' prompt. -Next, start barebox from DRAM: +Next, start barebox from DRAM:: nmon> g 80000000 Switch to console [cs0] @@ -188,3 +188,105 @@ Next, start barebox from DRAM: running /env/bin/init... /env/bin/init not found barebox:/ + +Allwinner D1 Nezha +------------------ + +Barebox has limited second-stage support for the Allwinner D1 Nezha (sun20i):: + + ARCH=riscv make rv64i_defconfig + ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- make + +The resulting ``./images/barebox-allwinner-d1.img`` can be used as 2nd stage +image which gets called by opensbi:: + + git clone https://github.com/tekkamanninja/opensbi -b allwinner_d1 + cd opensbi + CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic FW_PIC=y make + +The resulting ``./build/platform/generic/firmware/fw_dynamic.bin`` is loaded +by the 1st stage (spl) loader, which is basically a u-boot spl:: + + git clone https://github.com/smaeul/sun20i_d1_spl -b mainline + cd sun20i_d1_spl + CROSS_COMPILE=riscv64-linux-gnu- make p=sun20iw1p1 mmc + +The resulting ``./nboot/boot0_sdcard_sun20iw1p1.bin`` image used as 1st stage +bootloader which loads all necessary binaries: dtb, opensbi and barebox to the +dedicated places in DRAM. After loading it jumps to the opensbi image. The +initial dtb can be taken from u-boot:: + + git clone https://github.com/smaeul/u-boot.git -b d1-wip + cd u-boot + ARCH=riscv make nezha_defconfig + ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- make + +Make will print two warnings at the end of this command but those can be ignored +since we only want the devicetree blob which can be found under ``./u-boot.dtb``. + +The final image is build by mkimage. It is some sort of a self-defined toc1 +format. So we need to compile the mkimage with the toc1 format support as +first:: + + cd u-boot + make tools-only + +The resulting ``tools/mkimage`` is used to build the toc1 image which is loaded +by the 1st stage bootloader from the mmc interface. To build the final toc1 image +we need to specify a toc1.cfg like:: + + [opensbi] + file = <ABSOLUT_PATH_TO>/opensbi/build/platform/generic/firmware/fw_dynamic.bin + addr = 0x40000000 + [dtb] + file = <ABSOLUT_PATH_TO>/u-boot/u-boot.dtb + addr = 0x44000000 + [u-boot] + file = <ABSOLUT_PATH_TO>/barebox/images/barebox-allwinner-d1.img + addr = 0x4a000000 + +Then we need to call:: + + mkimage -T sunxi_toc1 -d toc1.cfg boot.toc1 + +The last part is to place the 1st stage bootloader and the ``boot.toc1`` image +onto the correct places. So the ROM loader can find the 1st stage bootloader +and the 1st bootloader can find the ``boot.toc1`` image. This is done by:: + + dd if=boot0_sdcard_sun20iw1p1.bin of=/dev/sd<X> bs=512 seek=16 + dd if=boot.toc1 of=/dev/sd<X> bs=512 seek=32800 + +Now plug in the sdcard and power device and you will see:: + + [309]HELLO! BOOT0 is starting! + [312]BOOT0 commit : 882671f-dirty + [315]set pll start + [317]periph0 has been enabled + [320]set pll end + [322]board init ok + + ... + + OpenSBI v0.9-204-gc9024b5 + ____ _____ ____ _____ + / __ \ / ____| _ \_ _| + | | | |_ __ ___ _ __ | (___ | |_) || | + | | | | '_ \ / _ \ '_ \ \___ \| _ < | | + | |__| | |_) | __/ | | |____) | |_) || |_ + \____/| .__/ \___|_| |_|_____/|____/_____| + | | + |_| + + Platform Name : Allwinner D1 Nezha + Platform Features : medeleg + + ... + + barebox 2022.08.0-00262-g38678340903b #1 Tue Sep 13 12:54:29 CEST 2022 + + + Board: Allwinner D1 Nezha + + ... + + barebox@Allwinner D1 Nezha:/ |