With driver model SPL support in place the remaining driver difference between U-Boot proper and SPL is that SPL does not support device tree. This series adds this support, using a Rockchip board as an example.
One problem with device tree is that U-Boot has no way of dropping features it does not need or use. For SPL this problem needs to be solved and this series uses the preprocessor for this. The 45KB Firefly device tree reduces to 693 bytes when unused material is removed. A better solution might involve the 'fdtgrep' tool but this has not made it into the device tree compiler as yet.
This series includes some changes aimed at reduce code size in SPL, including: - dropping alias sequence support (the aliases node) since many boards just use a single UART in SPL - adding a smaller panic() function that does not support printf()-format strings - removing device unbind code which will never be used in SPL
Overall the resulting SPL binary is 8829 bytes with my Linaro 4.8.2 compiler, including the device tree, using Thumb-2. Of this:
1768 bytes is driver model core code 1556 bytes is device tree code 693 bytes is the device tree itself 4756 is other code, including serial drivers, rodata and data
The last figure includes rodata incorrectly added by the tool chain [1]. With a bug-fixed gcc 4.9.2 the total size is 6893 bytes including device tree.
Approximately 750 bytes is used for strings and driver data (root device and serial) associated with driver model and device tree. This adds up an overhead of around 4750 bytes for driver model and device tree, including the code, rodata and device tree itself.
It should therefore be possible to use driver model and device tree in SPL for board that have enough SRAM. Clearly 4KB is impossible without further work (perhaps removing some error strings). I suspect 8KB would be tricky, allowing only 3KB for stack and other code. But 16KB should work OK.
SRAM sizes for recent SoCs I am aware of are:
Rockchip RK3288: 96KB Tegra 124: 128KB Samsung Exynos 5420: 384KB
The Rockchip Firefly was chosen for this work since it is a fairly recent board and is readily available. Rockchip engineers have been actively upstreaming code to Linux in the past year and there is a very full-featured U-Boot available. But it is invisible to most U-Boot people - mainline Rockchip support seems well overdue. This series does not make a serious start on that, since it only prints a message in SPL and then hangs, but additional work should get it booting to a prompt.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54303
Simon Glass (29): serial: ns16550: Add an option to specify the debug UART register shift dm: ns16550: Support non-byte register spacing with driver model dm: ns16550: Support CONFIG_SYS_NS16550_MEM32 with driver model serial: ns16550: Remove unnecessary init on UART setup fdt: arm: Drop device tree padding dm: core: Allow sequence alias support to be removed for SPL dm: core: Remove unbind operations when not required dm: Add a panic_str() function to reduce code size dm: core: Drop device removal error path when not supported fdt: sandbox: Move setup code from board_f to fdtdec fdt: Rename setup_fdt() and make it prepare also Move initf_malloc() to a common place Correct malloc_limit value for pre-relocation malloc() fdt: Add an option to disable device tree in SPL dts: Disable device tree for SPL on all boards fdt: Allow FDT functions to be built for SPL dm: core: Select device tree control correctly for SPL dm: Init device tree as well as driver model in SPL dm: serial: Don't support CONFIG_CONS_INDEX with device tree Remove SPL undefine of CONFIG_OF_CONTROL fdt: arm: Build device tree in SPL dm: rockchip: Add serial support rockchip: Bring in RK3288 device tree file includes and bindings rockchip: dts: Adjust device tree files for U-Boot SPL rockchip: Add base SoC files rockchip: Add basic support for firefly-rk3288 mkimage: Display a better list of available image types rockchip: Add the beginnings of an image tool rockchip: Add a simple README
arch/arm/Kconfig | 11 + arch/arm/Makefile | 1 + arch/arm/cpu/armv7/exynos/Kconfig | 8 + arch/arm/cpu/armv7/s5pc1xx/Kconfig | 2 + arch/arm/cpu/u-boot-spl.lds | 2 +- arch/arm/dts/Makefile | 6 +- arch/arm/dts/rk3288-firefly.dts | 82 ++ arch/arm/dts/rk3288-firefly.dtsi | 496 +++++++ arch/arm/dts/rk3288-thermal.dtsi | 90 ++ arch/arm/dts/rk3288.dtsi | 1480 ++++++++++++++++++++ arch/arm/include/asm/arch-rockchip/clock.h | 12 + arch/arm/include/asm/arch-rockchip/gpio.h | 5 + arch/arm/include/asm/arch-rockchip/grf.h | 181 +++ arch/arm/mach-rockchip/Kconfig | 44 + arch/arm/mach-rockchip/Makefile | 12 + arch/arm/mach-rockchip/board-spl.c | 54 + arch/arm/mach-rockchip/board.c | 17 + arch/arm/mach-rockchip/common.c | 11 + arch/arm/mach-rockchip/rk3288/Kconfig | 16 + arch/arm/mach-tegra/Kconfig | 3 + arch/sandbox/cpu/cpu.c | 41 + arch/sandbox/include/asm/u-boot-sandbox.h | 8 + board/firefly/firefly-rk3288/Kconfig | 15 + board/firefly/firefly-rk3288/MAINTAINERS | 6 + board/firefly/firefly-rk3288/Makefile | 7 + board/firefly/firefly-rk3288/firefly-rk3288.c | 7 + common/board_f.c | 84 +- common/dlmalloc.c | 11 + common/image.c | 55 +- common/spl/spl.c | 22 +- configs/Linksprite_pcDuino3_fdt_defconfig | 1 + configs/am335x_boneblack_vboot_defconfig | 1 + configs/arches_defconfig | 1 + configs/canyonlands_defconfig | 1 + configs/firefly-rk3288_defconfig | 11 + configs/galileo_defconfig | 1 + configs/microblaze-generic_defconfig | 1 + configs/odroid_defconfig | 1 + configs/origen_defconfig | 1 + configs/s5pc210_universal_defconfig | 1 + configs/socfpga_socrates_defconfig | 1 + configs/trats2_defconfig | 1 + configs/trats_defconfig | 1 + configs/zynq_microzed_defconfig | 1 + configs/zynq_zc70x_defconfig | 1 + configs/zynq_zc770_xm010_defconfig | 1 + configs/zynq_zc770_xm012_defconfig | 1 + configs/zynq_zc770_xm013_defconfig | 1 + configs/zynq_zed_defconfig | 1 + configs/zynq_zybo_defconfig | 1 + doc/README.rockchip | 83 ++ .../clock/rockchip,rk3288-cru.txt | 61 + doc/device-tree-bindings/clock/rockchip.txt | 77 + .../pinctrl/rockchip,pinctrl.txt | 157 +++ .../thermal/rockchip-thermal.txt | 68 + drivers/core/Kconfig | 9 + drivers/core/Makefile | 2 + drivers/core/device.c | 54 +- drivers/core/root.c | 14 +- drivers/core/uclass.c | 4 + drivers/serial/Kconfig | 19 + drivers/serial/Makefile | 1 + drivers/serial/ns16550.c | 44 +- drivers/serial/serial-uclass.c | 69 +- drivers/serial/serial_rockchip.c | 41 + dts/Kconfig | 11 +- dts/Makefile | 9 +- include/config_uncmd_spl.h | 3 + include/configs/firefly-rk3288.h | 50 + include/dm/uclass-internal.h | 8 + include/dt-bindings/clock/rk3288-cru.h | 378 +++++ include/dt-bindings/clock/rockchip,rk808.h | 11 + include/dt-bindings/pinctrl/rockchip.h | 34 + include/dt-bindings/power-domain/rk3288.h | 11 + include/dt-bindings/thermal/thermal.h | 17 + include/fdtdec.h | 16 + include/image.h | 12 + include/malloc.h | 3 + include/vsprintf.h | 23 + lib/Makefile | 6 + lib/fdtdec.c | 39 +- lib/vsprintf.c | 23 +- scripts/Makefile.lib | 12 +- scripts/Makefile.spl | 35 + scripts/Makefile.uncmd_spl | 2 + tools/Makefile | 1 + tools/mkimage.c | 59 +- tools/rkimage.c | 63 + 88 files changed, 4136 insertions(+), 212 deletions(-) create mode 100644 arch/arm/dts/rk3288-firefly.dts create mode 100644 arch/arm/dts/rk3288-firefly.dtsi create mode 100644 arch/arm/dts/rk3288-thermal.dtsi create mode 100644 arch/arm/dts/rk3288.dtsi create mode 100644 arch/arm/include/asm/arch-rockchip/clock.h create mode 100644 arch/arm/include/asm/arch-rockchip/gpio.h create mode 100644 arch/arm/include/asm/arch-rockchip/grf.h create mode 100644 arch/arm/mach-rockchip/Kconfig create mode 100644 arch/arm/mach-rockchip/Makefile create mode 100644 arch/arm/mach-rockchip/board-spl.c create mode 100644 arch/arm/mach-rockchip/board.c create mode 100644 arch/arm/mach-rockchip/common.c create mode 100644 arch/arm/mach-rockchip/rk3288/Kconfig create mode 100644 board/firefly/firefly-rk3288/Kconfig create mode 100644 board/firefly/firefly-rk3288/MAINTAINERS create mode 100644 board/firefly/firefly-rk3288/Makefile create mode 100644 board/firefly/firefly-rk3288/firefly-rk3288.c create mode 100644 configs/firefly-rk3288_defconfig create mode 100644 doc/README.rockchip create mode 100644 doc/device-tree-bindings/clock/rockchip,rk3288-cru.txt create mode 100644 doc/device-tree-bindings/clock/rockchip.txt create mode 100644 doc/device-tree-bindings/pinctrl/rockchip,pinctrl.txt create mode 100644 doc/device-tree-bindings/thermal/rockchip-thermal.txt create mode 100644 drivers/serial/serial_rockchip.c create mode 100644 include/configs/firefly-rk3288.h create mode 100644 include/dt-bindings/clock/rk3288-cru.h create mode 100644 include/dt-bindings/clock/rockchip,rk808.h create mode 100644 include/dt-bindings/pinctrl/rockchip.h create mode 100644 include/dt-bindings/power-domain/rk3288.h create mode 100644 include/dt-bindings/thermal/thermal.h create mode 100644 tools/rkimage.c