On 3/8/24 22:48, E Shattow wrote:
Yes this reference to GPIO high/low states is clearer to understand. Have you tested the DIP switch functionality to confirm?; It is not shown in the MilkV documentation or outdated schematics and I don't have a Mars to test. I did find function descriptions from what is likely cut-and-paste of VisionFive2 board reference.
Ref: https://github.com/milkv-mars/mars-files/blob/main/Mars_hardware_schematics/... https://github.com/milkv-mars/mars-files/blob/main/Mars_hardware_schematics/Mars_V1.11_20230821.pdf Sheet 7 of 22 JH7110 GPIOs There is a schematic for SW2 (bootloader button?) that lists an inset table:
- GPIO_1
- GPIO_0 - Boot
- 0
- 0 - Flash
- 0
- 1 - SD
- 1
- 0 - eMMC
- 1
- 1 - UART
That circuit on SW2 appears to pull high both RGPIO_1 and RGPIO_0 with transistors. Again, no DIP switch as this is an earlier revision.
Ref: https://doc-en.rvspace.org/VisionFive2/Developer_Guide/JH7110_Boot_UG.pdf https://doc-en.rvspace.org/VisionFive2/Developer_Guide/JH7110_Boot_UG.pdf page 9 table 1-4: RGPIO1=0x0 RGPIO0=0x0 Boot Source: Quad SPI NOR flash memory, Read SPL from Sector 0. RGPIO1=0x1 RGPIO0=0x1 Boot Source: UART0, (description of UART Xmodem function).
Following in the same document on page 13 figure 2-1 Boot Flow: JH7110supportsthefollowingbootdevices. QSPIFlash(ForSPL + OpenSBI + U-Boot)+NVMe/SDCard/eMMC(ForKernel+FileSystemandlater) Note: System will detect in sequence whether it can boot from the following device sequence: NVMe > SD > eMMC. For example,if the boot program is found on the SD, eMMC will be ignored.
The GPIOs select from where U-Boot SPL is loaded. Currently U-Boot SPL loads main U-Boot from the same device. But you could change it to scan multiple devices for main U-Boot.
Once you have successfully loaded main U-Boot, main U-Boot will scan the different boot devices. This includes NVME, eMMC, SD, USB, Network.
Currently upstream U-Boot development is moving from hard coded sequences in board files to configurable boot sequences.
Again in this document Figure 4-2 on page 17 is a visual listing of the DIP switch positions for QSPI, SDIO, eMMC, and UART boot modes, of the VisionFive2 board.
These are just the same switches as on the Milk-V.
The only consistent physical interface over VisionFive2, Mars, Star64, Mars CM all is RGPIO1=L RGPIO0=L SPI and RGPIO1=H RGPIO1=H UART; either by DIP switch or pushbutton attached circuit. So, I question our assumptions about what the actual behavior is for RGPIO1=H RGPIO0=L pairing and RGPIO1=L RGPIO0=H, and in what circumstance would there be followed a device sequence as suggested by the JH7110 reference. Why does the StarFive documentation list a JH7110 boot device sequence if there is also these H+L or L+H pairings to choose the device?
As said the device sequence including NVMe is not realized by the code loading U-Boot SPL. It is realized in main U-Boot.
Best regards
Heinrich
On Thu, Mar 7, 2024 at 6:37 PM Heinrich Schuchardt <heinrich.schuchardt@canonical.com mailto:heinrich.schuchardt@canonical.com> wrote:
On 3/8/24 00:20, E Shattow wrote: > > On Sun, Mar 3, 2024 at 5:02 AM Heinrich Schuchardt > <heinrich.schuchardt@canonical.com <mailto:heinrich.schuchardt@canonical.com> > <mailto:heinrich.schuchardt@canonical.com <mailto:heinrich.schuchardt@canonical.com>>> wrote: > ... > > +The board provides the DIP switches MSEL[1:0] to select the boot > device out of > +SPI flash, eMMC, SD-card, UART. To select booting from SD-card set > the DIP > +switches MSEL[1:0] to 10. > > > This does not match the [Milk-V Mars vendor > documentation](https://milkv.io/docs/mars/getting-started/bootloader <https://milkv.io/docs/mars/getting-started/bootloader> > <https://milkv.io/docs/mars/getting-started/bootloader <https://milkv.io/docs/mars/getting-started/bootloader>>). Maybe you have > a different board revision? Thank you for reviewing. My board revision is V1.21 according to the silk screen. The Milk-V Mars has DIP switches for the boot selection as shown in https://gist.github.com/xypron/e28f95b1ed6911aeb9699ba63ae1a885 <https://gist.github.com/xypron/e28f95b1ed6911aeb9699ba63ae1a885> If you look at the photo https://milkv.io/assets/images/mars-icon-04-e8814f18158a0e9d4387f4fa330693f1.webp <https://milkv.io/assets/images/mars-icon-04-e8814f18158a0e9d4387f4fa330693f1.webp> in the https://milkv.io/mars <https://milkv.io/mars> page, it also shows DIP switches (in the SPI-Flash position) on a rev 1.2 board. Did you see a board without DIP switches being sold? The silk screen markings on the board and the switch don't match. The same confusion exists on the VisionFive2. So maybe I should better write in a table: SPI-Flash: GPIO0=L GPIO1=L SD-Card: GPIO0=H GPIO1=L eMMC: GPIO0=L GPIO1=H UART: GPIO0=H GPIO1=H Best regards Heinrich