Allwinner sun50i SoCs contain an OpenRISC 1000 CPU that functions as a System Control Processor, or SCP. ARM Trusted Firmware (ATF) communicates with the SCP over SCPI to implement the PSCI system suspend, shutdown and reset functionality. Currently, SCP firmware is optional; the system will boot and run without it, but system suspend will be unavailable.
Since all communication with the SCP is mediated by ATF, the only thing U-Boot needs to do is load the firmware into SRAM. The SCP firmware occupies the last 16KiB of SRAM A2, immediately following ATF.
Signed-off-by: Samuel Holland samuel@sholland.org --- arch/arm/dts/sunxi-u-boot.dtsi | 16 ++++++++++++- board/sunxi/README.sunxi64 | 43 ++++++++++++++++++++++++++++------ 2 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/arch/arm/dts/sunxi-u-boot.dtsi b/arch/arm/dts/sunxi-u-boot.dtsi index ff3fff599f4..5ab7c6c23b7 100644 --- a/arch/arm/dts/sunxi-u-boot.dtsi +++ b/arch/arm/dts/sunxi-u-boot.dtsi @@ -2,8 +2,10 @@
#ifdef CONFIG_MACH_SUN50I_H6 #define BL31_ADDR 0x104000 +#define SCP_ADDR 0x114000 #else #define BL31_ADDR 0x44000 +#define SCP_ADDR 0x50000 #endif
/ { @@ -58,6 +60,18 @@ }; };
+ scp { + description = "SCP firmware"; + type = "firmware"; + arch = "or1k"; + compression = "none"; + load = <SCP_ADDR>; + + scp { + filename = "scp.bin"; + }; + }; + @fdt-SEQ { description = "NAME"; type = "flat_dt"; @@ -71,7 +85,7 @@ @config-SEQ { description = "NAME"; firmware = "atf"; - loadables = "uboot"; + loadables = "scp", "uboot"; fdt = "fdt-SEQ"; }; }; diff --git a/board/sunxi/README.sunxi64 b/board/sunxi/README.sunxi64 index 258921af22d..9a67e5301eb 100644 --- a/board/sunxi/README.sunxi64 +++ b/board/sunxi/README.sunxi64 @@ -14,8 +14,12 @@ Quick Start / Overview - Build the ARM Trusted Firmware binary (see "ARM Trusted Firmware (ATF)" below) $ cd /src/arm-trusted-firmware $ make PLAT=sun50i_a64 DEBUG=1 bl31 +- Build the SCP firmware binary (see "SCP firmware (Crust)" below) + $ cd /src/crust + $ make pine64_plus_defconfig && make -j5 scp - Build U-Boot (see "SPL/U-Boot" below) $ export BL31=/path/to/bl31.bin + $ export SCP=/src/crust/build/scp/scp.bin $ make pine64_plus_defconfig && make -j5 - Transfer to an uSD card (see "microSD card" below) $ dd if=u-boot-sunxi-with-spl.bin of=/dev/sdx bs=8k seek=1 @@ -24,13 +28,17 @@ Quick Start / Overview Building the firmware =====================
-The Allwinner A64/H5 firmware consists of three parts: U-Boot's SPL, an -ARM Trusted Firmware (ATF) build and the U-Boot proper. -The SPL will load both ATF and U-Boot proper along with the right device -tree blob (.dtb) and will pass execution to ATF (in EL3), which in turn will -drop into the U-Boot proper (in EL2). -As the ATF binary will become part of the U-Boot image file, you will need -to build it first. +The Allwinner A64/H5/H6 firmware consists of several parts: U-Boot's SPL, +ARM Trusted Firmware (ATF), optional System Control Processor (SCP) firmware +(e.g. Crust), and the U-Boot proper. + +The SPL will load all of the other firmware binaries into RAM, along with the +right device tree blob (.dtb), and will pass execution to ATF (in EL3). If SCP +firmware was loaded, ATF will power on the SCP and wait for it to boot. +ATF will then drop into U-Boot proper (in EL2). + +As the ATF binary and SCP firmware will become part of the U-Boot image file, +you will need to build them first.
ARM Trusted Firmware (ATF) ---------------------------- @@ -53,6 +61,27 @@ As sometimes the ATF build process is a bit picky about the toolchain used, or if you can't be bothered with building ATF, there are known working binaries in the firmware repository[3], purely for convenience reasons.
+ SCP firmware (Crust) +---------------------- +SCP firmware is responsible for implementing system suspend/resume, and (on +boards without a PMIC) soft poweroff/on. ATF contains fallback code for CPU +power control, so SCP firmware is optional if you don't need either of these +features. It runs on the AR100, with is an or1k CPU, not ARM, so it needs a +different cross toolchain. + +There is one SCP firmware implementation currently available, Crust: +$ git clone https://github.com/crust-firmware/crust +$ cd crust +$ export CROSS_COMPILE=or1k-linux-musl- +$ make pine64_plus_defconfig +$ make scp + +The same configuration generally works on any board with the same SoC (A64, H5, +or H6), so if there is no config for your board, use one for a similar board. + +Like for ATF, U-Boot finds the SCP firmware binary via an environment variable: +$ export SCP=/src/crust/build/scp/scp.bin + SPL/U-Boot ------------ Both U-Boot proper and the SPL are using the 64-bit mode. As the boot ROM