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diff --git a/qemu/roms/u-boot/doc/README.omap3 b/qemu/roms/u-boot/doc/README.omap3 new file mode 100644 index 000000000..a62c35740 --- /dev/null +++ b/qemu/roms/u-boot/doc/README.omap3 @@ -0,0 +1,220 @@ + +Summary +======= + +This README is about U-Boot support for TI's ARM Cortex-A8 based OMAP3 [1] +family of SoCs. TI's OMAP3 SoC family contains an ARM Cortex-A8. Additionally, +some family members contain a TMS320C64x+ DSP and/or an Imagination SGX 2D/3D +graphics processor and various other standard peripherals. + +Currently the following boards are supported: + +* OMAP3530 BeagleBoard [2] + +* Gumstix Overo [3] + +* TI EVM [4] + +* OpenPandora Ltd. Pandora [5] + +* TI/Logic PD Zoom MDK [6] + +* TI/Logic PD Zoom 2 [7] + +* CompuLab Ltd. CM-T35 [8] + +Toolchain +========= + +While ARM Cortex-A8 support ARM v7 instruction set (-march=armv7a) we compile +with -march=armv5 to allow more compilers to work. For U-Boot code this has +no performance impact. + +Build +===== + +* BeagleBoard: + +make omap3_beagle_config +make + +* Gumstix Overo: + +make omap3_overo_config +make + +* TI EVM: + +make omap3_evm_config +make + +* Pandora: + +make omap3_pandora_config +make + +* Zoom MDK: + +make omap3_zoom1_config +make + +* Zoom 2: + +make omap3_zoom2_config +make + +* CM-T35: + +make cm_t35_config +make + +* BlueLYNX-X: + +make omap3_mvblx_config +make + +Custom commands +=============== + +To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot +for OMAP3 supports custom user command + +nandecc hw/sw + +To be compatible with NAND drivers using SW ECC (e.g. kernel code) + +nandecc sw + +enables SW ECC calculation. HW ECC enabled with + +nandecc hw + +is typically used to write 2nd stage bootloader (known as 'x-loader') which is +executed by OMAP3's boot rom and therefore has to be written with HW ECC. + +For all other commands see + +help + +Interfaces +========== + +gpio +---- + +To set a bit : + + if (!gpio_request(N, "")) { + gpio_direction_output(N, 0); + gpio_set_value(N, 1); + } + +To clear a bit : + + if (!gpio_request(N, "")) { + gpio_direction_output(N, 0); + gpio_set_value(N, 0); + } + +To read a bit : + + if (!gpio_request(N, "")) { + gpio_direction_input(N); + val = gpio_get_value(N); + gpio_free(N); + } + if (val) + printf("GPIO N is set\n"); + else + printf("GPIO N is clear\n"); + +dma +--- +void omap3_dma_init(void) + Init the DMA module +int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); + Read config of the channel +int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); + Write config to the channel +int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst, + uint32_t sze) + Config source, destination and size of a transfer +int omap3_dma_wait_for_transfer(uint32_t chan) + Wait for a transfer to end - this hast to be called before a channel + or the data the channel transferd are used. +int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) + Read silicon Revision of the DMA module + +NAND +==== + +There are some OMAP3 devices out there with NAND attached. Due to the fact that +OMAP3 ROM code can only handle 1-bit hamming ECC for accessing first page +(place where SPL lives) we require this setup for u-boot at least when reading +the second progam within SPL. A lot of newer NAND chips however require more +than 1-bit ECC for the pages, some can live with 1-bit for the first page. To +handle this we can switch to another ECC algorithm after reading the payload +within SPL. + +BCH8 +---- + +To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on +OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH +and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW. +The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 +implementation for OMAP3 works for you so the u-boot version should also. +When you require the SPL to read with BCH8 there are two more configs to +change: + + * CONFIG_SYS_NAND_ECCPOS (must be the same as .eccpos in + GPMC_NAND_HW_BCH8_ECC_LAYOUT defined in + arch/arm/include/asm/arch-omap3/omap_gpmc.h) + * CONFIG_SYS_NAND_ECCSIZE must be 512 + * CONFIG_SYS_NAND_ECCBYTES must be 13 for this BCH8 setup + +Acknowledgements +================ + +OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by +several TI employees. + +Links +===== + +[1] OMAP3: + +http://www.ti.com/omap3 (high volume) and +http://www.ti.com/omap35x (broad market) + +[2] OMAP3530 BeagleBoard: + +http://beagleboard.org/ + +[3] Gumstix Overo: + +http://www.gumstix.net/Overo/ + +[4] TI EVM: + +http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html + +[5] OpenPandora Ltd. Pandora: + +http://openpandora.org/ + +[6] TI/Logic PD Zoom MDK: + +http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit + +[7] TI/Logic PD Zoom 2 + +http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf + +[8] CompuLab Ltd. CM-T35: + +http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm + +[9] TI OMAP3 U-Boot: + +http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz |