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Kconfig A D18-Mar-2022317 2516

MAINTAINERS A D18-Mar-2022138 76

Makefile A D18-Mar-2022189 134

README A D18-Mar-20221.9 KiB6445

spl_xea.c A D18-Mar-202210.9 KiB304236

xea.c A D18-Mar-20224.2 KiB208132

README

1 Building SPL/U-Boot for xea board
2 =================================
3 
4 Setup environment, configure and build, e.g. by:
5 
6  $ make imx28_xea_defconfig
7  $ make -j4 u-boot.sb u-boot.img
8 
9 Now you should see u-boot.sb and u-boot.img files in the build directory.
10 
11 
12 Booting
13 =======
14 
15 The boot ROM loads SPL from SPI NOR flash into SRAM.  SPL configures
16 DRAM and loads either a Linux kernel (falcon mode) or, if the rescue
17 pin is asserted, the main U-Boot.  Both kernel and U-Boot reside in
18 eMMC boot partition 0.  For redundancy, a copy of U-Boot is also
19 stored in SPI flash.  If a valid kernel image is not found, U-Boot is
20 loaded from eMMC or, if this fails, SPI flash.
21 
22 Boot area layout
23 ----------------
24 
25 SPI NOR
26 Offset          Function        File
27 ------------------------------------------
28 0x00000000      SPL             u-boot.sb
29 0x00010000      U-Boot          u-boot.img
30 0x00080000      Environment
31 
32 eMMC
33 Offset          Function        File
34 ------------------------------------------
35 0x00000000      U-Boot          u-boot.img
36 0x00080000      Devicetree      imx28-bttc.dtb
37 0x00100000      Kernel          uImage
38 
39 
40 Falcon mode
41 ===========
42 
43 In falcon mode, the default, SPL loads the kernel and devicetree
44 directly.  For this to work, the stored devicetree must include
45 correct "memory" and "chosen" nodes as these are not updated by SPL
46 before booting the kernel.
47 
48 
49 Updating from U-Boot
50 ====================
51 
52 The default U-Boot environment includes command sequences to update
53 SPL, U-Boot, and kernel over TFTP.  These are as follows:
54 
55 - update_spl: writes u-boot.sb to SPI NOR
56 - update_uboot: writes u-boot.img to eMMC and SPI NOR
57 - update_kernel: writes kernel and devicetree to eMMC
58 
59 They can be invoked at the U-Boot prompt using the "run" command,
60 e.g. "run update_spl" to update the SPL.
61 
62 These update commands download the above-named files from the
63 ${hostname} directory on the server provided by DHCP.
64