system/riscv/sifive_u.rst

56 Boot options
60 for loading a Linux kernel, a VxWorks kernel, a modified U-Boot bootloader
62 -bios. It also supports booting the unmodified U-Boot bootloader using the
76   offset 0xfc. U-Boot reads the serial number from the OTP memory, and uses
91   Mode Select (MSEL[3:0]) pins value, used to control where to boot from.
94   using the Mode Select pins on the chip. Typically, the boot process runs
98   1. Zeroth Stage Boot Loader (ZSBL), which is contained in an on-chip mask
102   2. First Stage Boot Loader (FSBL), which brings up PLLs and DDR memory.
103      This is U-Boot SPL.
104   3. Second Stage Boot Loader (SSBL), which further initializes additional
105      peripherals as needed. This is U-Boot proper combined with an OpenSBI
125 To boot the newly built Linux kernel in QEMU with the ``sifive_u`` machine:
131       -kernel arch/riscv/boot/Image \
135 Alternatively, we can use a custom DTB to boot the machine by inserting a CLINT
156       -kernel arch/riscv/boot/Image \
157       -dtb arch/riscv/boot/dts/sifive/hifive-unleashed-a00.dtb \
163 fix the 32-bit boot issue for Linux kernel v5.10.
175 line above to boot the 32-bit Linux kernel. A rootfs image containing 32-bit
176 applications shall be used in order for kernel to boot to user space.
196 To boot the VxWorks kernel in QEMU with the ``sifive_u`` machine, use:
210 Running U-Boot
213 U-Boot mainline v2024.01 release is tested at the time of writing. To build a
214 U-Boot mainline bootloader that can be booted by the ``sifive_u`` machine, use
224 You will get spl/u-boot-spl.bin and u-boot.itb file in the build tree.
226 To start U-Boot using the ``sifive_u`` machine, prepare an SPI flash image, or
242           partition u-boot-spl {
243                   image = "u-boot-spl.bin"
248           partition u-boot {
249                   image = "u-boot.itb"
268           partition u-boot-spl {
269                   image = "u-boot-spl.bin"
274           partition u-boot {
275                   image = "u-boot.itb"
281 Assume U-Boot binaries are put in the same directory as the config file,
288 Boot U-Boot from SD card, by specifying msel=11 and pass the SD card image
295       -bios /path/to/u-boot-spl.bin \
298 Changing msel= value to 6, allows booting U-Boot from the SPI flash:
304       -bios /path/to/u-boot-spl.bin \
307 Note when testing U-Boot, QEMU automatically generated device tree blob is
308 not used because U-Boot itself embeds device tree blobs for U-Boot SPL and
309 U-Boot proper. Hence the number of cores and size of memory have to match
312 Above use case is to run upstream U-Boot for the SiFive HiFive Unleashed
314 develop and test the recommended RISC-V boot flow with a real world use
315 case: ZSBL (in QEMU) loads U-Boot SPL from SD card or SPI flash to L2LIM,
316 then U-Boot SPL loads the combined payload image of OpenSBI fw_dynamic
317 firmware and U-Boot proper.
319 However sometimes we want to have a quick test of booting U-Boot on QEMU
321 way can be used, which is to create a U-Boot S-mode image by modifying the
322 configuration of U-Boot:
333 This changes U-Boot to use the QEMU generated device tree blob, and bypass
334 running the U-Boot SPL stage.
336 Boot the 64-bit U-Boot S-mode image directly:
342       -kernel /path/to/u-boot.bin
344 It's possible to create a 32-bit U-Boot S-mode image as well.
358 Use the same command line options to boot the 32-bit U-Boot S-mode image:
364       -kernel /path/to/u-boot.bin