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* Pandora: 45 46make omap3_pandora_config 47make 48 49* Zoom MDK: 50 51make omap3_zoom1_config 52make 53 54* Zoom 2: 55 56make omap3_zoom2_config 57make 58 59* CM-T35: 60 61make cm_t35_config 62make 63 64 65Custom commands 66=============== 67 68To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot 69for OMAP3 supports custom user command 70 71nandecc hw/sw 72 73To be compatible with NAND drivers using SW ECC (e.g. kernel code) 74 75nandecc sw 76 77enables SW ECC calculation. HW ECC enabled with 78 79nandecc hw 80 81is typically used to write 2nd stage bootloader (known as 'x-loader') which is 82executed by OMAP3's boot rom and therefore has to be written with HW ECC. 83 84For all other commands see 85 86help 87 88Interfaces 89========== 90 91gpio 92---- 93 94To set a bit : 95 96 if (!gpio_request(N, "")) { 97 gpio_direction_output(N, 0); 98 gpio_set_value(N, 1); 99 } 100 101To clear a bit : 102 103 if (!gpio_request(N, "")) { 104 gpio_direction_output(N, 0); 105 gpio_set_value(N, 0); 106 } 107 108To read a bit : 109 110 if (!gpio_request(N, "")) { 111 gpio_direction_input(N); 112 val = gpio_get_value(N); 113 gpio_free(N); 114 } 115 if (val) 116 printf("GPIO N is set\n"); 117 else 118 printf("GPIO N is clear\n"); 119 120dma 121--- 122void omap3_dma_init(void) 123 Init the DMA module 124int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); 125 Read config of the channel 126int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); 127 Write config to the channel 128int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst, 129 uint32_t sze) 130 Config source, destination and size of a transfer 131int omap3_dma_wait_for_transfer(uint32_t chan) 132 Wait for a transfer to end - this hast to be called before a channel 133 or the data the channel transferd are used. 134int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) 135 Read silicon Revision of the DMA module 136 137NAND 138==== 139 140There are some OMAP3 devices out there with NAND attached. Due to the fact that 141OMAP3 ROM code can only handle 1-bit hamming ECC for accessing first page 142(place where SPL lives) we require this setup for u-boot at least when reading 143the second progam within SPL. A lot of newer NAND chips however require more 144than 1-bit ECC for the pages, some can live with 1-bit for the first page. To 145handle this we can switch to another ECC algorithm after reading the payload 146within SPL. 147 148BCH8 149---- 150 151To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on 152OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH 153and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW. 154The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 155implementation for OMAP3 works for you so the u-boot version should also. 156When you require the SPL to read with BCH8 there are two more configs to 157change: 158 159 * CONFIG_SYS_NAND_ECCPOS (must be the same as .eccpos in 160 GPMC_NAND_HW_BCH8_ECC_LAYOUT defined in 161 arch/arm/include/asm/arch-omap3/omap_gpmc.h) 162 * CONFIG_SYS_NAND_ECCSIZE must be 512 163 * CONFIG_SYS_NAND_ECCBYTES must be 13 for this BCH8 setup 164 165Acknowledgements 166================ 167 168OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by 169several TI employees. 170 171Links 172===== 173 174[1] OMAP3: 175 176http://www.ti.com/omap3 (high volume) and 177http://www.ti.com/omap35x (broad market) 178 179[2] OMAP3530 BeagleBoard: 180 181http://beagleboard.org/ 182 183[3] Gumstix Overo: 184 185http://www.gumstix.net/Overo/ 186 187[4] TI EVM: 188 189http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html 190 191[5] OpenPandora Ltd. Pandora: 192 193http://openpandora.org/ 194 195[6] TI/Logic PD Zoom MDK: 196 197http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit 198 199[7] TI/Logic PD Zoom 2 200 201http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf 202 203[8] CompuLab Ltd. CM-T35: 204 205http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm 206 207[9] TI OMAP3 U-Boot: 208 209http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz 210