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* BlueLYNX-X: 72 73make omap3_mvblx_config 74make 75 76Custom commands 77=============== 78 79To make U-Boot for OMAP3 support NAND device SW or HW ECC calculation, U-Boot 80for OMAP3 supports custom user command 81 82nandecc hw/sw 83 84To be compatible with NAND drivers using SW ECC (e.g. kernel code) 85 86nandecc sw 87 88enables SW ECC calculation. HW ECC enabled with 89 90nandecc hw 91 92is typically used to write 2nd stage bootloader (known as 'x-loader') which is 93executed by OMAP3's boot rom and therefore has to be written with HW ECC. 94 95For all other commands see 96 97help 98 99Interfaces 100========== 101 102gpio 103---- 104 105To set a bit : 106 107 if (!gpio_request(N, "")) { 108 gpio_direction_output(N, 0); 109 gpio_set_value(N, 1); 110 } 111 112To clear a bit : 113 114 if (!gpio_request(N, "")) { 115 gpio_direction_output(N, 0); 116 gpio_set_value(N, 0); 117 } 118 119To read a bit : 120 121 if (!gpio_request(N, "")) { 122 gpio_direction_input(N); 123 val = gpio_get_value(N); 124 gpio_free(N); 125 } 126 if (val) 127 printf("GPIO N is set\n"); 128 else 129 printf("GPIO N is clear\n"); 130 131dma 132--- 133void omap3_dma_init(void) 134 Init the DMA module 135int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config); 136 Read config of the channel 137int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config); 138 Write config to the channel 139int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst, 140 uint32_t sze) 141 Config source, destination and size of a transfer 142int omap3_dma_wait_for_transfer(uint32_t chan) 143 Wait for a transfer to end - this hast to be called before a channel 144 or the data the channel transferd are used. 145int omap3_dma_get_revision(uint32_t *minor, uint32_t *major) 146 Read silicon Revision of the DMA module 147 148NAND 149==== 150 151There are some OMAP3 devices out there with NAND attached. Due to the fact that 152OMAP3 ROM code can only handle 1-bit hamming ECC for accessing first page 153(place where SPL lives) we require this setup for u-boot at least when reading 154the second progam within SPL. A lot of newer NAND chips however require more 155than 1-bit ECC for the pages, some can live with 1-bit for the first page. To 156handle this we can switch to another ECC algorithm after reading the payload 157within SPL. 158 159BCH8 160---- 161 162To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on 163OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH 164to enable the library and CONFIG_NAND_OMAP_BCH8 to to enable hardware assisted 165syndrom generation to your board config. 166The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8 167implementation for OMAP3 works for you so the u-boot version should also. 168When you require the SPL to read with BCH8 there are two more configs to 169change: 170 171 * CONFIG_SYS_NAND_ECCPOS (must be the same as .eccpos in 172 GPMC_NAND_HW_BCH8_ECC_LAYOUT defined in 173 arch/arm/include/asm/arch-omap3/omap_gpmc.h) 174 * CONFIG_SYS_NAND_ECCSIZE must be 512 175 * CONFIG_SYS_NAND_ECCBYTES must be 13 for this BCH8 setup 176 177Acknowledgements 178================ 179 180OMAP3 U-Boot is based on U-Boot tar ball [9] for BeagleBoard and EVM done by 181several TI employees. 182 183Links 184===== 185 186[1] OMAP3: 187 188http://www.ti.com/omap3 (high volume) and 189http://www.ti.com/omap35x (broad market) 190 191[2] OMAP3530 BeagleBoard: 192 193http://beagleboard.org/ 194 195[3] Gumstix Overo: 196 197http://www.gumstix.net/Overo/ 198 199[4] TI EVM: 200 201http://focus.ti.com/docs/toolsw/folders/print/tmdxevm3503.html 202 203[5] OpenPandora Ltd. Pandora: 204 205http://openpandora.org/ 206 207[6] TI/Logic PD Zoom MDK: 208 209http://www.logicpd.com/products/devkit/ti/zoom_mobile_development_kit 210 211[7] TI/Logic PD Zoom 2 212 213http://www.logicpd.com/sites/default/files/1012659A_Zoom_OMAP34x-II_MDP_Brief.pdf 214 215[8] CompuLab Ltd. CM-T35: 216 217http://www.compulab.co.il/t3530/html/t3530-cm-datasheet.htm 218 219[9] TI OMAP3 U-Boot: 220 221http://beagleboard.googlecode.com/files/u-boot_beagle_revb.tar.gz 222