My goal when I started on this project a year ago was to get to linux userspace within a second from power on. Oh, and it had to be secure! Contrast that to the two minutes it took the STLinux demo to come up.
It was obvious that the accepted way of running an FSBL, then SSBL was going to blow the time budget. There really wasn't a good solution, and traditional falcon mode with "spl export" command was not secure.
I chose to use SPL with a FIT payload. We have to add certain logic to SPL, as well as some FDT modifications that would be normally done in u-boot. The boot flow is
SPL -> OP-TEE -> Linux
Incidentally, these patches are some of the earlier ones I wrote for this project. It didn't make sense to publish them at the time, as the supporting infrastructure was not in place then
I decided not to separate these patches into mini-series.
Alexandru Gagniuc (10): stm32mp1: Add support for baudrates higher than 115200 stm32mp1: Add support for falcon mode boot from SD card board: stm32mp1: Implement board_fit_config_name_match() for SPL fdt_support: Implement fdt_ethernet_set_macaddr() arm: stm32mp: bsec: Do not skip .probe() for SPL arm: stm32mp: Factor out reading MAC address from OTP stm32mp1: spl: Configure MAC address when booting OP-TEE lib: Makefile: Make optee library available in SPL ARM: dts: stm32mp: Add OP-TEE "/firmware" node to SPL dtb stm32mp1: spl: Copy optee nodes to target FDT for OP-TEE payloads
arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi | 1 + arch/arm/mach-stm32mp/bsec.c | 2 +- arch/arm/mach-stm32mp/cpu.c | 59 ++++++++++++++----- .../arm/mach-stm32mp/include/mach/sys_proto.h | 3 + arch/arm/mach-stm32mp/spl.c | 3 + board/st/stm32mp1/spl.c | 49 +++++++++++++++ common/fdt_support.c | 30 ++++++++++ include/configs/stm32mp1.h | 17 ++++++ include/fdt_support.h | 17 ++++++ lib/Makefile | 2 +- 10 files changed, 167 insertions(+), 16 deletions(-)