| Message ID | 20200418193228.44209-2-atish.patra@wdc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | RISC-V DT related fixes for reserved memory & UEFI | expand |
On Sun, Apr 19, 2020 at 3:32 AM Atish Patra <atish.patra at wdc.com> wrote: > > Linux booting protocol mandates that register "a0" contains the hartid. > However, U-Boot can not pass the hartid via a0 during via standard UEFI > protocol. DT nodes are commonly used to pass such information to the OS. > > Add a DT node under chosen node to indicate the boot hartid. EFI stub > in Linux kernel will parse this node and pass it to the real kernel > in "a0" before jumping to it. > > Signed-off-by: Atish Patra <atish.patra at wdc.com> > Reviewed-by: Rick Chen <rick at andestech.com> > Reviewed-by: Bin Meng <bmeng.cn at gmail.com> > Tested-by: Heinrich Schuchardt <xypron.glpk at gmx.de> > --- > arch/riscv/lib/bootm.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > Verified on booting OS, and dump DTB /chosen node Tested-by: Bin Meng <bmeng.cn at gmail.com>
diff --git a/arch/riscv/lib/bootm.c b/arch/riscv/lib/bootm.c index fad16901c5f2..87cadad5016d 100644 --- a/arch/riscv/lib/bootm.c +++ b/arch/riscv/lib/bootm.c @@ -28,6 +28,28 @@ __weak void board_quiesce_devices(void) int arch_fixup_fdt(void *blob) { +#ifdef CONFIG_EFI_LOADER + int err; + u32 size; + int chosen_offset; + + size = fdt_totalsize(blob); + err = fdt_open_into(blob, blob, size + 32); + if (err < 0) { + printf("Device Tree can't be expanded to accommodate new node"); + return err; + } + chosen_offset = fdt_path_offset(blob, "/chosen"); + if (chosen_offset < 0) { + err = fdt_add_subnode(blob, 0, "chosen"); + if (err < 0) { + printf("chosen node can not be added\n"); + return err; + } + } + /* Overwrite the boot-hartid as U-Boot is the last stage BL */ + fdt_setprop_u32(blob, chosen_offset, "boot-hartid", gd->arch.boot_hart); +#endif return 0; }