On Mon, Dec 28, 2020 at 3:10 PM Anup Patel <anup@xxxxxxxxxxxxxx> wrote: > > On Mon, Dec 28, 2020 at 7:05 PM Vitaly Wool <vitaly.wool@xxxxxxxxxxxx> wrote: > > > > On Mon, Dec 28, 2020 at 12:59 PM Anup Patel <anup@xxxxxxxxxxxxxx> wrote: > > > > > > On Sat, Dec 26, 2020 at 10:03 PM Vitaly Wool <vitaly.wool@xxxxxxxxxxxx> wrote: > > > > > > > > Sometimes, especially in a production system we may not want to > > > > use a "smart bootloader" like u-boot to load kernel, ramdisk and > > > > device tree from a filesystem on eMMC, but rather load the kernel > > > > from a NAND partition and just run it as soon as we can, and in > > > > this case it is convenient to have device tree compiled into the > > > > kernel binary. Since this case is not limited to MMU-less systems, > > > > let's support it for these which have MMU enabled too. > > > > > > > > Signed-off-by: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx> > > > > --- > > > > arch/riscv/Kconfig | 1 - > > > > arch/riscv/mm/init.c | 12 ++++++++++-- > > > > 2 files changed, 10 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > > > index 2b41f6d8e458..9464b4e3a71a 100644 > > > > --- a/arch/riscv/Kconfig > > > > +++ b/arch/riscv/Kconfig > > > > @@ -419,7 +419,6 @@ endmenu > > > > > > > > config BUILTIN_DTB > > > > def_bool n > > > > - depends on RISCV_M_MODE > > > > depends on OF > > > > > > > > menu "Power management options" > > > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > > > index 87c305c566ac..5d1c7a3ec01c 100644 > > > > --- a/arch/riscv/mm/init.c > > > > +++ b/arch/riscv/mm/init.c > > > > @@ -194,12 +194,20 @@ void __init setup_bootmem(void) > > > > setup_initrd(); > > > > #endif /* CONFIG_BLK_DEV_INITRD */ > > > > > > > > + /* > > > > + * If DTB is built in, no need to reserve its memblock. > > > > + * OTOH, initial_boot_params has to be set to properly copy DTB > > > > + * before unflattening later on. > > > > + */ > > > > + if (IS_ENABLED(CONFIG_BUILTIN_DTB)) > > > > + initial_boot_params = __va(dtb_early_pa); > > > > > > Don't assign initial_boot_params directly here because the > > > early_init_dt_scan() will do it. > > > > early_init_dt_scan will set initial_boot_params to dtb_early_va from > > the early mapping which will be gone by the time > > unflatten_and_copy_device_tree() is called. > > That's why we are doing early_init_dt_verify() again for the MMU-enabled > case which already takes care of your concern. I might be out in the woods here but... Do you mean the call to early_init_dt_verify() in setup_arch() which is compiled out completely in the CONFIG_BUILTIN_DTB case? Or is there any other call that I'm overlooking? Best regards, Vitaly > We use early_init_dt_verify() like most architectures to set the initial DTB. > > > > > > The setup_vm() is supposed to setup dtb_early_va and dtb_early_pa > > > for MMU-enabled case so please add a "#ifdef" over there for the > > > built-in DTB case. > > > > > > > + else > > > > + memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); > > > > + > > > > /* > > > > * Avoid using early_init_fdt_reserve_self() since __pa() does > > > > * not work for DTB pointers that are fixmap addresses > > > > */ > > > > > > This comment needs to be updated and moved along the memblock_reserve() > > > statement. > > > > > > > - memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); > > > > - > > > > early_init_fdt_scan_reserved_mem(); > > > > dma_contiguous_reserve(dma32_phys_limit); > > > > memblock_allow_resize(); > > > > -- > > > > 2.29.2 > > > > > > > > > > This patch should be based upon Damiens builtin DTB patch. > > > Refer, https://www.spinics.net/lists/linux-gpio/msg56616.html > > > > Thanks for the pointer, however I don't think our patches have > > intersections. Besides, Damien is dealing with the MMU-less case > > there. > > Damien's patch is also trying to move to use generic BUILTIN_DTB > support for the MMU-less case so it is similar work hence the chance > of patch conflict. > > Regards, > Anup
