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 26Toolchain 27========= 28 29While ARM Cortex-A8 support ARM v7 instruction set (-march=armv7a) we compile 30with -march=armv5 to allow more compilers to work. For U-Boot code this has 31no performance impact. 32 33Build 34===== 35 36* BeagleBoard: 37 38make omap3_beagle_config 39make 40 41* Gumstix Overo: 42 43make omap3_overo_config 44make 45 46* TI EVM: 47 48make omap3_evm_config 49make 50 51* Pandora: 52 53make omap3_pandora_config 54make 55 56* Zoom MDK: 57 58make omap3_zoom1_config 59make 60 61* Zoom 2: 62 63make omap3_zoom2_config 64make 65 66* CM-T35: 67 68make cm_t35_config 69make 70 71 72Custom commands 73=============== 74 75To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot 76for OMAP3 supports custom user command 77 78nandecc hw/sw 79 80To be compatible with NAND drivers using SW ECC (e.g. kernel code) 81 82nandecc sw 83 84enables SW ECC calculation. HW ECC enabled with 85 86nandecc hw 87 88is typically used to write 2nd stage bootloader (known as 'x-loader') which is 89executed by OMAP3's boot rom and therefore has to be written with HW ECC. 90 91For all other commands see 92 93help 94 95Interfaces 96========== 97 98gpio 99---- 100 101To set a bit : 102 103 if (!gpio_request(N, "")) { 104 gpio_direction_output(N, 0); 105 gpio_set_value(N, 1); 106 } 107 108To clear a bit : 109 110 if (!gpio_request(N, "")) { 111 gpio_direction_output(N, 0); 112 gpio_set_value(N, 0); 113 } 114 115To read a bit : 116 117 if (!gpio_request(N, "")) { 118 gpio_direction_input(N); 119 val = gpio_get_value(N); 120 gpio_free(N); 121 } 122 if (val) 123 printf("GPIO N is set\n"); 124 else 125 printf("GPIO N is clear\n"); 126 127dma 128--- 129void omap3_dma_init(void) 130 Init the DMA module 131int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); 132 Read config of the channel 133int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); 134 Write config to the channel 135int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst, 136 uint32_t sze) 137 Config source, destination and size of a transfer 138int omap3_dma_wait_for_transfer(uint32_t chan) 139 Wait for a transfer to end - this hast to be called before a channel 140 or the data the channel transferd are used. 141int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) 142 Read silicon Revision of the DMA module 143 144NAND 145==== 146 147There are some OMAP3 devices out there with NAND attached. Due to the fact that 148OMAP3 ROM code can only handle 1-bit hamming ECC for accessing first page 149(place where SPL lives) we require this setup for u-boot at least when reading 150the second progam within SPL. A lot of newer NAND chips however require more 151than 1-bit ECC for the pages, some can live with 1-bit for the first page. To 152handle this we can switch to another ECC algorithm after reading the payload 153within SPL. 154 155BCH8 156---- 157 158To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on 159OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH 160and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW. 161The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 162implementation for OMAP3 works for you so the u-boot version should also. 163When you require the SPL to read with BCH8 there are two more configs to 164change: 165 166 * CONFIG_SYS_NAND_ECCPOS (must be the same as .eccpos in 167 GPMC_NAND_HW_BCH8_ECC_LAYOUT defined in 168 arch/arm/include/asm/arch-omap3/omap_gpmc.h) 169 * CONFIG_SYS_NAND_ECCSIZE must be 512 170 * CONFIG_SYS_NAND_ECCBYTES must be 13 for this BCH8 setup 171 172Acknowledgements 173================ 174 175OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by 176several TI employees. 177 178Links 179===== 180 181[1] OMAP3: 182 183http://www.ti.com/omap3 (high volume) and 184http://www.ti.com/omap35x (broad market) 185 186[2] OMAP3530 BeagleBoard: 187 188http://beagleboard.org/ 189 190[3] Gumstix Overo: 191 192http://www.gumstix.net/Overo/ 193 194[4] TI EVM: 195 196http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html 197 198[5] OpenPandora Ltd. Pandora: 199 200http://openpandora.org/ 201 202[6] TI/Logic PD Zoom MDK: 203 204http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit 205 206[7] TI/Logic PD Zoom 2 207 208http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf 209 210[8] CompuLab Ltd. CM-T35: 211 212http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm 213 214[9] TI OMAP3 U-Boot: 215 216http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz 217