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https://github.com/brain-hackers/u-boot-brain
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![Tom Rini](/assets/img/avatar_default.png)
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
70 lines
1.9 KiB
Plaintext
70 lines
1.9 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0+
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#
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# (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
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Build & Run instructions:
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1) Install mkbootimg and dtbTool from
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git://codeaurora.org/quic/kernel/skales (15ece94f09 worked for me)
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2) Setup CROSS_COMPILE to aarch64 compiler
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3) make dragonboard410c_config
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4) make
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5) generate fake, empty ramdisk (can have 0 bytes)
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$ touch rd
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6) Generate qualcomm device tree table with dtbTool [1]
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$ dtbTool -o dt.img arch/arm/dts
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7) Generate Android boot image with mkbootimg [2]:
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$ mkbootimg --kernel=u-boot-dtb.bin --output=u-boot.img --dt=dt.img \
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--pagesize 2048 --base 0x80000000 --ramdisk=rd --cmdline=""
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8) Enter fastboot (reboot board with vol- button pressed)
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9) Boot it:
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$ fastboot boot u-boot.img
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or flash as kernel:
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$ fastboot flash boot u-boot.img
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$ fastboot reboot
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What is working:
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- UART
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- GPIO (SoC)
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- SD
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- eMMC
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- Reset
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- USB in EHCI mode (usb starts does switch device->host, usb stop does the opposite)
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- PMIC GPIOS (but not in generic subsystem)
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- PMIC "special" buttons (power, vol-)
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What is not working / known bugs:
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- SDHCI is slow (~2.5MiB/s for SD and eMMC)
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[1] To boot any kernel image, Little Kernel requires valid device tree for the
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platform it runs on. dtbTool creates device tree table that Little Kernel scans.
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Later on proper device tree is passed to next boot stage.
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Full device tree is not required to boot u-boot. Enough would be:
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/dts-v1/;
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/ {
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model = "Qualcomm Technologies, Inc. Dragonboard 410c";
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compatible = "qcom,dragonboard", "qcom,apq8016-sbc";
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qcom,msm-id = <0xce 0x0 0xf8 0x0 0xf9 0x0 0xfa 0x0 0xf7 0x0>;
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qcom,board-id = <0x10018 0x0>;
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#address-cells = <0x2>;
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#size-cells = <0x2>;
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chosen { };
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aliases { };
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memory {
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device_type = "memory";
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reg = <0 0x80000000 0 0x3da00000>;
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};
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};
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but for simplicity (and because size of image is not that critical) we use
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existing Qualcomm device trees.
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[2] Note that ramdisk is required, even if it is unused.
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