1 2Summary 3======= 4 5This README is about U-Boot support for TI's ARM Cortex-A8 based OMAP3 [1] 6family of SoCs. TI's OMAP3 SoC family contains an ARM Cortex-A8. Additionally, 7some family members contain a TMS320C64x+ DSP and/or an Imagination SGX 2D/3D 8graphics processor and various other standard peripherals. 9 10Currently the following boards are supported: 11 12* OMAP3530 BeagleBoard [2] 13 14* Gumstix Overo [3] 15 16* TI EVM [4] 17 18* OpenPandora Ltd. Pandora [5] 19 20* TI/Logic PD Zoom MDK [6] 21 22* TI/Logic PD Zoom 2 [7] 23 24* CompuLab Ltd. CM-T35 [8] 25 26Build 27===== 28 29* BeagleBoard: 30 31make omap3_beagle_config 32make 33 34* Gumstix Overo: 35 36make omap3_overo_config 37make 38 39* TI EVM: 40 41make omap3_evm_config 42make 43 44* Zoom 2: 45 46make omap3_zoom2_config 47make 48 49* CM-T35: 50 51make cm_t35_config 52make 53 54 55Custom commands 56=============== 57 58To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot 59for OMAP3 supports custom user command 60 61nandecc hw/sw 62 63To be compatible with NAND drivers using SW ECC (e.g. kernel code) 64 65nandecc sw 66 67enables SW ECC calculation. HW ECC enabled with 68 69nandecc hw 70 71is typically used to write 2nd stage bootloader (known as 'x-loader') which is 72executed by OMAP3's boot rom and therefore has to be written with HW ECC. 73 74For all other commands see 75 76help 77 78Interfaces 79========== 80 81gpio 82---- 83 84To set a bit : 85 86 if (!gpio_request(N, "")) { 87 gpio_direction_output(N, 0); 88 gpio_set_value(N, 1); 89 } 90 91To clear a bit : 92 93 if (!gpio_request(N, "")) { 94 gpio_direction_output(N, 0); 95 gpio_set_value(N, 0); 96 } 97 98To read a bit : 99 100 if (!gpio_request(N, "")) { 101 gpio_direction_input(N); 102 val = gpio_get_value(N); 103 gpio_free(N); 104 } 105 if (val) 106 printf("GPIO N is set\n"); 107 else 108 printf("GPIO N is clear\n"); 109 110dma 111--- 112void omap3_dma_init(void) 113 Init the DMA module 114int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); 115 Read config of the channel 116int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); 117 Write config to the channel 118int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst, 119 uint32_t sze) 120 Config source, destination and size of a transfer 121int omap3_dma_wait_for_transfer(uint32_t chan) 122 Wait for a transfer to end - this hast to be called before a channel 123 or the data the channel transferd are used. 124int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) 125 Read silicon Revision of the DMA module 126 127NAND 128==== 129 130There are some OMAP3 devices out there with NAND attached. Due to the fact that 131OMAP3 ROM code can only handle 1-bit hamming ECC for accessing first page 132(place where SPL lives) we require this setup for u-boot at least when reading 133the second progam within SPL. A lot of newer NAND chips however require more 134than 1-bit ECC for the pages, some can live with 1-bit for the first page. To 135handle this we can switch to another ECC algorithm after reading the payload 136within SPL. 137 138BCH8 139---- 140 141To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on 142OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH 143and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW. 144The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 145implementation for OMAP3 works for you so the u-boot version should also. 146When you require the SPL to read with BCH8 there are two more configs to 147change: 148 149 * CONFIG_SYS_NAND_ECCPOS (must be the same as .eccpos in 150 GPMC_NAND_HW_BCH8_ECC_LAYOUT defined in 151 arch/arm/include/asm/arch-omap3/omap_gpmc.h) 152 * CONFIG_SYS_NAND_ECCSIZE must be 512 153 * CONFIG_SYS_NAND_ECCBYTES must be 13 for this BCH8 setup 154 155Acknowledgements 156================ 157 158OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by 159several TI employees. 160 161Links 162===== 163 164[1] OMAP3: 165 166http://www.ti.com/omap3 (high volume) and 167http://www.ti.com/omap35x (broad market) 168 169[2] OMAP3530 BeagleBoard: 170 171http://beagleboard.org/ 172 173[3] Gumstix Overo: 174 175http://www.gumstix.net/Overo/ 176 177[4] TI EVM: 178 179http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html 180 181[5] OpenPandora Ltd. Pandora: 182 183http://openpandora.org/ 184 185[6] TI/Logic PD Zoom MDK: 186 187http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit 188 189[7] TI/Logic PD Zoom 2 190 191http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf 192 193[8] CompuLab Ltd. CM-T35: 194 195http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm 196 197[9] TI OMAP3 U-Boot: 198 199http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz 200