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5f1600e03e
The documentation states that SPL is enabled in all config options for the da850. This incorrect, because devices booting from NOR do not need the SPL to do the low level initializion because when booting from NOR, the board is able to execute in place (XIP) This also clarifies that SPL isn't only used for booting from SPI, because it is also used for booting from MMC and NAND for those devices supporting those boot options. Signed-off-by: Adam Ford <aford173@gmail.com>
82 lines
2.1 KiB
Text
82 lines
2.1 KiB
Text
Summary
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=======
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Note: this document used to be about the entire family of DaVinci SOCs but the
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support for the DM* family and DA830 has since been dropped.
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This README is about U-Boot support for TI's DA850 SoC. This SOC has an OMAP
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part number but is very similar to the DaVinci series.
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Currently the following boards are supported:
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* TI DA850 EVM
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* TI OMAP-L138 LCDK
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* Lego EV3
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Build
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=====
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* TI DA850 EVM:
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make da850evm_config
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make
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* TI OMAP-L138 LCDK
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make omapl138_lcdk_defconfig
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make
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* Lego EV3
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make legoev3_defconfig
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make
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Bootloaders
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===============
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For DA850 an SPL (secondary program loader, see doc/README.SPL) is provided
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to load U-Boot from SPI flash, MMC or NAND. The SPL takes care of the low level
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initialization.
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The SPL is built as u-boot.ais for all DA850 defconfigs except those booting
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from NOR flash. The resulting image file can be programmed to the SPI flash
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of the DA850 EVM/LCDK.
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Devices that support booting from NOR utilize execute in place (XIP) and do
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not require SPL to perform low level initialization.
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Environment Variables
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=====================
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The DA850 EVM allows the user to specify the maximum cpu clock allowed by the
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silicon, in Hz, via an environment variable "maxcpuclk".
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The maximum clock rate allowed depends on the silicon populated on the EVM.
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Please make sure you understand the restrictions placed on this clock in the
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device specific datasheet before setting up this variable. This information is
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passed to the Linux kernel using the ATAG_REVISION atag.
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If "maxcpuclk" is not defined, the configuration CONFIG_DA850_EVM_MAX_CPU_CLK
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is used to obtain this information.
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Links
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=====
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1) TI DA850 EVM
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http://focus.ti.com/docs/prod/folders/print/omap-l138.html
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http://www.logicpd.com/products/development-kits/zoom-omap-l138-evm-development-kit
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2) TI OMAP-L138 LCDK
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http://focus.ti.com/docs/prod/folders/print/omap-l138.html
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http://www.ti.com/tool/TMDXLCDK138
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Davinci special defines
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=======================
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CONFIG_SYS_DV_NOR_BOOT_CFG: AM18xx based boards, booting in NOR Boot mode
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need a "NOR Boot Configuration Word" stored
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in the NOR Flash. This define adds this.
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More Info about this, see:
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spraba5a.pdf chapter 3.1
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