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