Re: [yocto] [meta-rockchip][PATCH v2 3/4] remove /boot partition

[Trevor Woerner <twoerner@gmail.com>]

On Fri 2024-02-16 @ 11:06:03 AM, Quentin Schulz wrote:
> Hi Trevor,
> 
> On 2/16/24 09:29, Trevor Woerner via lists.yoctoproject.org wrote:
> > In order to boot successfully, most Rockchip SoCs require a specific
> > partitioning scheme which was defined many years (and many SoCs) ago. That
> > partitioning scheme places the SPL and U-Boot at specific offsets at the
> > start of the boot block device:
> > 
> > 	https://opensource.rock-chips.com/wiki_Partitions
> > 
> > The Rockchip partitioning scheme goes on to also define the locations and
> > sizes of a number of additional partitions, including the "boot" and "root"
> > partitions.
> > 
> > Since both the SPL and U-Boot have already been placed on the block device,
> > the "boot" partition only contains the extlinux config file and the
> > kernel+dtb/fitImage; it doesn't contain any bootloader artifacts (other
> > than the extlinux config).
> > 
> > The location and size of the SPL partition is a hard dependency since the
> 
> Just because I like being pedantic, I don't thhink the size is a hard
> dependency. The location is (well there are a few possible though :) ), but
> the size is part of the header(s) that is parsed by the BootROM, the BootROM
> will only fetch what it needs as far as I remember. It's a bit of convoluted
> code but it's done in tools/rkcommon.c in U-Boot source code.
> 
> What we can say though is that the TPL+SPL has a maximum size, since it
> needs to fit inside the SRAM. But I don't think any SoC has been released by
> Rockchip that has 2.5MiB of SRAM, it's usually a few tens of KiB max only.
> Anyway, the message is fine, just wanted to give a bit more info there.

I appreciate pedantic, so don't hesitate to jump in. In fact up until this
point we have been playing fast and loose with the partition sizes, so I
already had proof that the sizing was not a hard dependency. And I never mind
in-depth explanations and experiences.

> 
> [...]
> 
> > diff --git a/conf/machine/include/rockchip-extlinux.inc b/conf/machine/include/rockchip-extlinux.inc
> > new file mode 100644
> > index 000000000000..3af7ed629e34
> > --- /dev/null
> > +++ b/conf/machine/include/rockchip-extlinux.inc
> > @@ -0,0 +1,12 @@
> > +UBOOT_EXTLINUX ?= "1"
> > +UBOOT_EXTLINUX_ROOT ?= "root=PARTLABEL=root"
> > +UBOOT_EXTLINUX_FDTDIR ?= "${@bb.utils.contains('KERNEL_IMAGETYPE', 'fitImage', '', '/boot', d)}"
> > +NONFITDT ?= "${@d.getVar('KERNEL_DEVICETREE').split('/')[1]}"
> 
> Maybe keep the comment explaining the logic of this line?

Done. But tweaked a little. The reasons for having it before (as part of the
boot files is slightly different than the reason for keeping it for EXTLINUX,
but very similar.

> 
> > +UBOOT_EXTLINUX_FDT ?= "${@bb.utils.contains('KERNEL_IMAGETYPE', 'fitImage', '', '${NONFITDT}', d)}"
> > +UBOOT_EXTLINUX_CONSOLE ?= "earlycon console=tty1 console=${RK_CONSOLE_DEVICE},${RK_CONSOLE_BAUD}n8"
> > +UBOOT_EXTLINUX_KERNEL_ARGS ?= "rootwait rw rootfstype=ext4"
> > +UBOOT_EXTLINUX_KERNEL_IMAGE ?= "/boot/${KERNEL_IMAGETYPE}"
> > +UBOOT_EXTLINUX_LABELS ?= "default"
> > +UBOOT_EXTLINUX_MENU_DESCRIPTION:default ?= "${MACHINE}"
> > +
> > +MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "u-boot-extlinux"
> 
> Going back to the mail I sent a few minutes ago on the v1 (which was sent
> after your v2 was sent :) ), I have a gut feeling we need _RDEPENDS here and
> not _RRECOMMENDS.

Ah got it. I misunderstood your comments. I thought you had been asking
whether it was necessary at all and I was pointing out that without that
package being added to the rootfs it wouldn't work.

Not a problem, I've upgraded it from a recommendation to a dependency.