On 07.05.19 19:25, Andreas Dannenberg wrote:
TI K3 SoCs like the AM654x devices are fundamentally dependent on a firmware called SYSFW (System Firmware) being loaded into the dedicated DMSC (Device Management and Security Controller) processor to provide various services via TISCI (Texas Instruments System Control Interface) to manage device aspects such as core bringup, power, clocks, security, and so on across the entire SoC.
Currently public U-Boot does not boot on an actual AM654x EVM due to the missing loading and startup of SYSFW, with this being the only piece missing preventing a successful boot from SD/MMC-type media. This gap is addressed with this patch series.
Note that the loading and starting of SYSFW is done in the context of board_init_f() in SPL which poses some unique challenges due to the very constrained nature of this environment (minimal amount of SRAM, no DDR yet available).
In order to be as lean as possible on resource use an approach was chosen that extends the existing SPL loader framework to be usable beyond the usual "loading U-Boot" use case. While this patch series only makes changes to the MMC/SD card loader framework to support eMMC/MMC/SD FS- and sector/partition-based RAW boot at this time we have this solution in production today but extended to SPI/OSPI and Y-Modem without any issues.
While I also have a working solution based on the existing FS loader framework this has its own challenges, namely by its very nature only addressing a subset of our use cases (no eMMC/SD RAW boot support for example), being heavier on resource usage (needing to use ENV to pass parameters), and not addressing the need to probe the boot peripheral. This particular framework works well for use cases requiring to load firmware from FS-based media once DDR is up and U-Boot is in a more "initialized" state but it is not a one-fits all solution for very early use in SPL board_init_f() accross different boot modes.
And would it be an option to improve the loader (maybe dropping the "fs" from its name)? I think it's an "fs" loader because its idea has been copied from Linux. I think in U-Boot, it's more common to have things at a raw offset instead of a file system. Just thinking...
And the current state of that fs_loader is like it is because it fits its single user (socfpga stratix 10), I think.
Anyway, even if you do need yet another loader, would it make sense to create a common file instead of adding this in your arch/mach?
Regards, Simon
Andreas Dannenberg (10): mmc: k3_arasan: Allow driver to probe without PDs specified spl: Allow skipping clearing BSS during relocation spl: Make image loader infrastructure more universal arm: K3: Introduce System Firmware loader framework armV7R: K3: am654: Allow using SPL BSS pre-relocation armv7R: K3: am654: Use full malloc implementation in SPL armV7R: K3: am654: Load SYSFW binary and config from boot media configs: am65x_evm_r5: All sysfw to be loaded via MMC configs: am65x_hs_evm_r5: All sysfw to be loaded via MMC configs: am65x_hs_evm: Add Support for eMMC boot
Faiz Abbas (2): configs: am65x_evm: Add Support for eMMC boot am65x: README: Add eMMC layout and flash instructions
Lokesh Vutla (1): armv7R: dts: k3: am654: Update mmc nodes for loading sysfw
arch/arm/dts/k3-am654-r5-base-board.dts | 18 ++ arch/arm/lib/crt0.S | 3 + arch/arm/mach-k3/Kconfig | 40 +++ arch/arm/mach-k3/Makefile | 1 + arch/arm/mach-k3/am6_init.c | 34 ++- arch/arm/mach-k3/include/mach/sysfw-loader.h | 12 + arch/arm/mach-k3/sysfw-loader.c | 263 +++++++++++++++++++ board/ti/am65x/Kconfig | 1 + board/ti/am65x/README | 52 ++++ common/spl/Kconfig | 13 + common/spl/spl_fit.c | 14 + common/spl/spl_mmc.c | 76 ++++-- configs/am65x_evm_a53_defconfig | 2 + configs/am65x_evm_r5_defconfig | 7 +- configs/am65x_hs_evm_a53_defconfig | 2 + configs/am65x_hs_evm_r5_defconfig | 7 +- drivers/mmc/k3_arsan_sdhci.c | 16 +- include/configs/am65x_evm.h | 30 ++- include/spl.h | 26 ++ 19 files changed, 577 insertions(+), 40 deletions(-) create mode 100644 arch/arm/mach-k3/include/mach/sysfw-loader.h create mode 100644 arch/arm/mach-k3/sysfw-loader.c