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Many boot image configuration files refer to the appropriate documentation file, but these references contain typos in the directory and file name. Fix them. Also fix reference to doc/README.SPL file. Signed-off-by: Anatolij Gustschin <agust@denx.de> Cc: Prafulla Wadaskar <prafulla@marvell.com> Cc: Stefano Babic <sbabic@denx.de> Acked-by: Stefano Babic <sbabic@denx.de> |
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| README.omap3 | ||
Overview of SPL on OMAP3 devices ================================ Introduction ------------ This document provides an overview of how SPL functions on OMAP3 (and related such as am35x and am37x) processors. Methodology ----------- On these platforms the ROM supports trying a sequence of boot devices. Once one has been used successfully to load SPL this information is stored in memory and the location stored in a register. We will read this to determine where to read U-Boot from in turn. Memory Map ---------- This is an example of a typical setup. See top-level README for documentation of which CONFIG variables control these values. For a given board and the amount of DRAM available to it different values may need to be used. Note that the size of the SPL text rodata and data is enforced with a CONFIG option and growing over that size results in a link error. The SPL stack starts at the top of SRAM (which is configurable) and grows downward. The space between the top of SRAM and the enforced upper bound on the size of the SPL text, data and rodata is considered the safe stack area. Details on confirming this behavior are shown below. A portion of the system memory map looks as follows: SRAM: 0x40200000 - 0x4020FFFF DDR1: 0x80000000 - 0xBFFFFFFF Option 1 (SPL only): 0x40200800 - 0x4020BBFF: Area for SPL text, data and rodata 0x4020E000 - 0x4020FFFC: Area for the SPL stack. 0x80000000 - 0x8007FFFF: Area for the SPL BSS. 0x80100000: CONFIG_SYS_TEXT_BASE of U-Boot 0x80208000 - 0x80307FFF: malloc() pool available to SPL. Option 2 (SPL or X-Loader): 0x40200800 - 0x4020BBFF: Area for SPL text, data and rodata 0x4020E000 - 0x4020FFFC: Area for the SPL stack. 0x80008000: CONFIG_SYS_TEXT_BASE of U-Boot 0x87000000 - 0x8707FFFF: Area for the SPL BSS. 0x87080000 - 0x870FFFFF: malloc() pool available to SPL. For the areas that reside within DDR1 they must not be used prior to s_init() completing. Note that CONFIG_SYS_TEXT_BASE must be clear of the areas that SPL uses while running. This is why we have two versions of the memory map that only vary in where the BSS and malloc pool reside.