On 25.04.25 09:38, Maud Spierings wrote:
On 4/24/25 13:26, E Shattow wrote:
Overall I think this patch is acceptable as-is and I'll be willing to
make a later series with my suggestions; it's documentation so it is
never really completed, I think, and I spend an hour or two editing then
decide that what I want to do is its own other series. None of the what
I'd like to suggest here should delay a PR for this series.
On 4/24/25 05:13, Heinrich Schuchardt wrote:
Describe building U-Boot for the board and booting.
Carve out common information for JH7110 boards into an include.
Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com>
---
[...]
+Booting from SD-Card
+--------------------
+
+The device boot ROM loads U-Boot SPL (u-boot-spl.bin.normal.out)
from the
+partition with type GUID 2E54B353-1271-4842-806F-E436D6AF6985. You
are free
+to choose any partition number.
+
+With the default configuration U-Boot SPL loads the U-Boot FIT image
+(u-boot.itb) from partition 2
(CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=0x2).
+When formatting it is recommended to use GUID
+BC13C2FF-59E6-4262-A352-B275FD6F7172 for this partition.
+
+Booting from eMMC
+-----------------
+
+The device boot ROM tries to load U-Boot SPL (u-boot-
spl.bin.normal.out) from
+sector 0 of the eMMC's main hardware partition. But this conflicts
with GPT
+partitioning. Fortunately eMMC can alternatively load U-Boot SPL
from a backup
+position.
+
+For U-Boot SPL (u-boot-spl.bin.normal.out) starting at sector 2048
(position
+0x100000) write the following bytes to the eMMC device after GPT
partitioning:
+
+======= ========================
+Address Bytes
+======= ========================
+0x0000 40 02 00 00 00 00 10 00
+0x0290 40 02 00 00 00 00 10 00
+======= ========================
+
+With the default configuration U-Boot SPL loads the U-Boot FIT image
+(u-boot.itb) from partition 2
(CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=0x2).
+When formatting it is recommended to use GUID
+BC13C2FF-59E6-4262-A352-B275FD6F7172 for this partition.
+
+Booting from UART
+-----------------
+
+The boot ROM supports the X-modem protocol to upload
+spl/u-boot-spl.bin.normal.out. U-Boot SPL support loading the FIT image
+u-boot.itb via the Y-modem protocol.
+
+Due to restrictions of the boot ROM not all X-modem implementations are
+compatible. The package tio (https://github.com/tio/tio) has been
found to be
+usable.
JH7110 Boot User Guide says "Since document release 1.2, boot from SD
Card or eMMC is no longer recommended. But to maintain the code
structure, the following SD/eMMC boot address allocations are modified
as "reserved". Be aware of this change when designing your device based
on JH7110." [1]
1:https://doc-en.rvspace.org/VisionFive2/Developer_Guide/
JH7110_Boot_UG.pdf
So this is important we preserve documentation how SD-card and eMMC Boot
source modes can be prepared that are since dropped from official
documentation. Yet on my patch for bootph-pre-ram device-tree hints to
LKML there is Hal (StarFive) and some other people that want this
functionality of SD-card and eMMC boot to remain working in U-Boot even
though it's recommended against and dropped from official StarFive
documentation.
Can confirm that I would like this functionality to stay, as I've used
it a couple of times already on the fml13v01 board specifically to test
firmware before flashing it to spi flash.
The functionality is in the Boot ROM. So unless somebody changes the
lithography mask it won't change.
I believe it is actually the default boot mode selected by deepcomputing
on new boards, but don't quote me on that.
The fml13v01 comes without installed eMMC. My board came with U-Boot on
SPI flash.
I have only confirmed the sd card to work though, since my eMMC is my
main drive and is already full of efi/bootfs/rootfs.
I should try that uart booting at some point, I already use tio. Would
love to see a more detailed how to on it. I guess set to uart, then
ctrl+t x and then just send the spl, then ctrl+t x to send the FIT?
Ctrl+t x to send u-boot-spl.bin.normal.out.
Ctrl+t y to send u-boot.itb. We use Y-Modem at that stage.
https://docs.u-boot.org/en/v2025.01/board/starfive/milk-v_mars_cm.html
had this well described.
We can add in more detail again after this series.
Best regards
Heinrich
Kind regards,
Maud
I don't know, which is it? This appears to be an academic exercise to
make those deprecated boot modes working. It certainly belongs in
jh7110_common.rst as something interesting the hardware may be capable
of, but not as the recommended standard operating procedure.
@ Hal can you describe what the JH7110 boot code is doing for SD-card
and eMMC Boot modes? What magic numbers and logic is this process? If
you want these boot modes to be functional then please help with the
documentation here that is now deleted from StarFive officially.
With that,
Reviewed-by: E Shattow <e...@freeshell.de>
