1 2 Summary 3 ======= 4 5 This README is about U-Boot support for TI's ARM Cortex-A8 based OMAP3 [1] 6 family of SoCs. TI's OMAP3 SoC family contains an ARM Cortex-A8. Additionally, 7 some family members contain a TMS320C64x+ DSP and/or an Imagination SGX 2D/3D 8 graphics processor and various other standard peripherals. 9 10 Currently 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 26 Toolchain 27 ========= 28 29 While ARM Cortex-A8 support ARM v7 instruction set (-march=armv7a) we compile 30 with -march=armv5 to allow more compilers to work. For U-Boot code this has 31 no performance impact. 32 33 Build 34 ===== 35 36 * BeagleBoard: 37 38 make omap3_beagle_config 39 make 40 41 * Gumstix Overo: 42 43 make omap3_overo_config 44 make 45 46 * TI EVM: 47 48 make omap3_evm_config 49 make 50 51 * Pandora: 52 53 make omap3_pandora_config 54 make 55 56 * Zoom MDK: 57 58 make omap3_zoom1_config 59 make 60 61 * Zoom 2: 62 63 make omap3_zoom2_config 64 make 65 66 * CM-T35: 67 68 make cm_t35_config 69 make 70 71 72 Custom commands 73 =============== 74 75 To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot 76 for OMAP3 supports custom user command 77 78 nandecc hw/sw 79 80 To be compatible with NAND drivers using SW ECC (e.g. kernel code) 81 82 nandecc sw 83 84 enables SW ECC calculation. HW ECC enabled with 85 86 nandecc hw 87 88 is typically used to write 2nd stage bootloader (known as 'x-loader') which is 89 executed by OMAP3's boot rom and therefore has to be written with HW ECC. 90 91 For all other commands see 92 93 help 94 95 Interfaces 96 ========== 97 98 gpio 99 ---- 100 101 To set a bit : 102 103 if (!gpio_request(N, "")) { 104 gpio_direction_output(N, 0); 105 gpio_set_value(N, 1); 106 } 107 108 To clear a bit : 109 110 if (!gpio_request(N, "")) { 111 gpio_direction_output(N, 0); 112 gpio_set_value(N, 0); 113 } 114 115 To 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"); 126 127 dma 128 --- 129 void omap3_dma_init(void) 130 Init the DMA module 131 int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); 132 Read config of the channel 133 int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); 134 Write config to the channel 135 int 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 138 int 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. 141 int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) 142 Read silicon Revision of the DMA module 143 144 NAND 145 ==== 146 147 There are some OMAP3 devices out there with NAND attached. Due to the fact that 148 OMAP3 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 150 the second progam within SPL. A lot of newer NAND chips however require more 151 than 1-bit ECC for the pages, some can live with 1-bit for the first page. To 152 handle this we can switch to another ECC algorithm after reading the payload 153 within SPL. 154 155 BCH8 156 ---- 157 158 To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on 159 OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH 160 and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW. 161 The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 162 implementation for OMAP3 works for you so the u-boot version should also. 163 When you require the SPL to read with BCH8 there are two more configs to 164 change: 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 171 172 Acknowledgements 173 ================ 174 175 OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by 176 several TI employees. 177 178 Links 179 ===== 180 181 [1] OMAP3: 182 183 http://www.ti.com/omap3 (high volume) and 184 http://www.ti.com/omap35x (broad market) 185 186 [2] OMAP3530 BeagleBoard: 187 188 http://beagleboard.org/ 189 190 [3] Gumstix Overo: 191 192 http://www.gumstix.net/Overo/ 193 194 [4] TI EVM: 195 196 http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html 197 198 [5] OpenPandora Ltd. Pandora: 199 200 http://openpandora.org/ 201 202 [6] TI/Logic PD Zoom MDK: 203 204 http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit 205 206 [7] TI/Logic PD Zoom 2 207 208 http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf 209 210 [8] CompuLab Ltd. CM-T35: 211 212 http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm 213 214 [9] TI OMAP3 U-Boot: 215 216 http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz 217