天嵌IMX6开发板测试-第一篇

1.看下开发板介绍

1 品牌: 天嵌
2 CPU型号: NXP i.MX6Q
3 架构: Cortex_A9
4 主频: 4*1GHz
5 内存: 2GB DDR3
6 存储: 8GB eMMC FLA（64GB可扩）

2. 看下相关驱动啥的。

驱动  在内核中的源码位置  系统中的设备名称
 emmc/sdcard 驱动
drivers/mmc/host：sdhci-esdhc-imx.c
sdhci.c
sdhci-platform.c
sdhci-pltfm.c
  /dev/mmcblk*
 LCD 与 LVDS 驱动  drivers/video/mxc/ldb.c
mxc_dispdrv.c
mxc_dvi.c
mxc_ipuv3_fb.c
mxc_lcdif.c
  /dev/fb*
 电阻触摸屏驱动 drivers/input/touchscreen/tsc2007.module  dev/input/event*
 电容触摸屏驱动 drivers/input/touchscreen/gt811.module  dev/input/event*
 USB otg 驱动 drivers/usb/otg/fsl_otg.c  
 有线网络驱动 drivers/net/fec.module  eth0
 串口驱动
drivers/tty/serial/imx.c
mxc_uart_early.c
serial_core.c
  /dev/ttySAC*
 sgtl5000声卡驱动 sound/soc/imx/*  /dev/snd/*
 I2C 驱动 drivers/i2c/busses/i2c-imx.c  
 按键驱动 drivers/input/keyboard/gpio_keys.c  dev/input/event*
 红外驱动 drivers/input/keyboard/tq_hs0038.module  dev/input/event*
 背光灯驱动 drivers/video/backlight/pwm_bl.c drivers/video/backlight/backlight.c  
 pwm 驱动 arch/arm/plat-mxc/pwm.c  
 RTC 驱动 drivers/rtc/rtc-pcf8563.c  /dev/rtc0
 看门狗驱动 drivers/watchdog/imx2_wdt.c  /dev/watchdog
 多媒体摄像头驱动 drivers/media/video/mxc/capture/*  /dev/video*

3. 看下资料的下载，在淘宝找的

 下载资料  下载链接
 TQIMX6_android_V3.12.part01  http://pan.baidu.com/s/1slA1doD 密码：vpad
 TQIMX6_android_V3.12.part02  http://pan.baidu.com/s/1mikSS1E 密码：cac7
 TQIMX6_android_V3.12.part03  http://pan.baidu.com/s/1kVmqJKb 密码：x5yj
 TQIMX6_android_V3.12.part04  http://pan.baidu.com/s/1eR9RvRO 密码：vwra
 TQIMX6_android_V3.12.part05  http://pan.baidu.com/s/1hrIAHOK 密码：nhfe
 TQIMX6_android_V3.12.part06  http://pan.baidu.com/s/1gfLAL4R 密码：qyu6
 TQIMX6_android_V3.12.part07  http://pan.baidu.com/s/1hsgXpwK 密码：l7h7
 TQIMX6_android_V3.12.part08  http://pan.baidu.com/s/1dFniWmP 密码：bo8r
 TQIMX6_android_V3.12.part09  http://pan.baidu.com/s/1bo7p7f5 密码：nva2
 TQIMX6_android_V3.12.part10  http://pan.baidu.com/s/1mhRqdQw 密码：hawo
 Android镜像（6.0）  http://pan.baidu.com/s/1qXEWAxm 密码：pljv
 Linux镜像（4.1）  http://pan.baidu.com/s/1dFpQUNv 密码：2b8l
 Linux文件系统镜像.part1  http://pan.baidu.com/s/1jHPYnBK 密码：3t0h
 Linux文件系统镜像.part2  http://pan.baidu.com/s/1bo9XzD9 密码：pgim
 Linux平台工具  http://pan.baidu.com/s/1miGGWPU 密码：5fhr
 Linux资源  http://pan.baidu.com/s/1skS1Oc9 密码：g1ud
 Windows平台工具  http://pan.baidu.com/s/1pLMG23x 密码：hihw
 配套电路图  http://pan.baidu.com/s/1hsw6ulm 密码：92ym
 配套教材集  https://pan.baidu.com/s/1nvQj4N3 密码：g9v7
 配套芯片手册  http://pan.baidu.com/s/1dEUSeL7 密码：sx1b
 TQIMX6Q(V3) QT5.5开发境搭建  http://pan.baidu.com/s/1i4Q3hTb 密码：vh9f
 Qt快速入门攻略  http://www.armbbs.net/forum.php?mod=viewthread&tid=21338&extra=

4. 看下uboot的源码，根据手册是

1 ./build_sh 编译

5. 是的，你比较厉害，-j8用8个线程去编译。

1 export ARCH=arm
2 export CROSS_COMPILE=arm-linux-
3 make mx6q_sabresd_android_config
4 make -j8

6. 找到mx6q_sabresd_android_config，没搞明白，2个make可以放在一起？打开IMX6_CoreC_CD\Linux 源码包\uboot源码\uboot_IMX6_CoreC_1.3.4_for_Linux\Makefile

1 mx6q_sabresd_config            \
2 mx6q_sabresd_android_config             \
3 mx6q_sabresd_mfg_config            \
4 mx6q_sabresd_iram_config    : unconfig
5     @[ -z "$(findstring iram_,$@)" ] || \
6         { echo "TEXT_BASE = 0x00907000" >$(obj)board/freescale/mx6q_sabresd/config.tmp ; \
7           echo "... with iram configuration" ; \
8         }
9     @$(MKCONFIG) $(@:_config=) arm arm_cortexa8 mx6q_sabresd freescale mx6

7. 上面的几个参数，arm是构架 arm_cortexa8是CPU型号 mx6q_sabresd是板子的型号 freescale mx6

8. 找到链接文件uboot_IMX6_CoreC_1.3.4_for_Linux\board\freescale\mx6q_sabresd\u-boot.lds

 1 OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
 2 OUTPUT_ARCH(arm)
 3 ENTRY(_start)
 4 SECTIONS
 5 {
 6     . = 0x00000000;  //放置的起始位置
 7 
 8     . = ALIGN(4); //4字节对齐
 9     .text       :   //代码段
10     {
11       /* WARNING - the following is hand-optimized to fit within    */
12       /* the sector layout of our flash chips!    XXX FIXME XXX    */
13       board/freescale/mx6q_sabresd/flash_header.module    (.text.flasheader)  //天嵌定制？
14       cpu/arm_cortexa8/start.o //启动文件
15       board/freescale/mx6q_sabresd/libmx6q_sabresd.a    (.text)
16       lib_arm/libarm.a        (.text)
17       net/libnet.a            (.text)
18       drivers/mtd/libmtd.a        (.text)
19       drivers/mmc/libmmc.a        (.text)
20 
21       . = DEFINED(env_offset) ? env_offset : .;
22       common/env_embedded.o(.text)
23 
24       *(.text)
25     }
26 
27     . = ALIGN(4);  //只读数据段,ROM
28     .rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }
29 
30     . = ALIGN(4); //数据段
31     .data : { *(.data) }
32 
33     . = ALIGN(4);
34     .got : { *(.got) }
35 
36     . = .;
37     __u_boot_cmd_start = .;
38     .u_boot_cmd : { *(.u_boot_cmd) }
39     __u_boot_cmd_end = .;
40 
41     . = ALIGN(4);
42     _end_of_copy = .; /* end_of ROM copy code here */
43 
44     /* Extend to align to 0x1000, then put the Hab Data */
45     . = ALIGN(0x1000);
46     __hab_data = .;
47     . = . + 0x2000;
48     __data_enc_key = .;
49     /* actually, only 64bytes are needed, but this generates
50         a size multiple of 512bytes, which is optimal for SD boot */
51     . = . + 0x200;
52     __hab_data_end = .;
53     /* End of Hab Data, Place it before BSS section */
54 
55     __bss_start = .;
56     .bss : { *(.bss) }
57     _end = .;
58 }

9. 第一行，这个不清楚是啥，天嵌定制的？

board/freescale/mx6q_sabresd/flash_header.module    (.text.flasheader)

10.第2个链接的文件是start.c

#include <config.h>
#include <version.h>

.globl _start  //定义一个全局可见的变量
_start: b    reset  //问题，哪里算是_start的结束？下一个冒号的位置
    ldr    pc, _undefined_instruction  //未定义指令
    ldr    pc, _software_interrupt //软件中断向量
    ldr    pc, _prefetch_abort //预取指令中断向量
    ldr    pc, _data_abort//数据操作异常向量
    ldr    pc, _not_used /、未使用
    ldr    pc, _irq//慢速中断向量
    ldr    pc, _fiq//快速中断向量

_undefined_instruction: .word undefined_instruction
_software_interrupt:    .word software_interrupt
_prefetch_abort:    .word prefetch_abort
_data_abort:        .word data_abort
_not_used:        .word not_used
_irq:            .word irq
_fiq:            .word fiq
_pad:            .word 0x12345678 /* now 16*4=64 */
.global _end_vect
_end_vect:

11. 上面的.wordirq说是是什么意思，点是什么意思？加点的是伪指令，不会被编译的，理解如下.word是一个汇编伪指令，表示是一个字节，.word是伪操作，用于分配一小段字内存单元

1 _software_interrupt:    .word software_interrupt  //_software_interrupt = software_interrupt

12. 下面是reset的代码

 1 reset:
 2     /*
 3      * set the cpu to SVC32 mode
 4      *//ARM有7种模式，SVC是特权模式，可以访问所有寄存器
 5     mrs    r0, cpsr
 6     bic    r0, r0, #0x1f
 7     orr    r0, r0, #0xd3
 8     msr    cpsr,r0
33     /* the mask ROM code should have PLL and others stable */
34 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
35     bl    cpu_init_crit
36 #endif

13.首先会将CPU的工作模式设置为svc32模式，然后便调用 cpu_init_crit ，需要注意的是，这里使用的是 bl 指令，也就是说在运行完 cpu_init_crit 标号处的代码之后，会通过这个指令返回来

1 mov    pc, lr            @ back to my caller

14. 跳转到cpu_init_crit

 1 cpu_init_crit:
 2     /*
 3      * Invalidate L1 I/D
 4      */
 5     mov    r0, #0            @ set up for MCR
 6     mcr    p15, 0, r0, c8, c7, 0    @ invalidate TLBs
 7     mcr    p15, 0, r0, c7, c5, 0    @ invalidate icache
 8 
 9     /*
10      * disable MMU stuff and caches
11      */
12     mrc    p15, 0, r0, c1, c0, 0
13     bic    r0, r0, #0x00002000    @ clear bits 13 (--V-)
14     bic    r0, r0, #0x00000007    @ clear bits 2:0 (-CAM)
15     orr    r0, r0, #0x00000002    @ set bit 1 (--A-) Align
16     orr    r0, r0, #0x00000800    @ set bit 12 (Z---) BTB
17     mcr    p15, 0, r0, c1, c0, 0
18 
19     /*
20      * Jump to board specific initialization...
21      * The Mask ROM will have already initialized
22      * basic memory. Go here to bump up clock rate and handle
23      * wake up conditions.
24      */
25     mov    ip, lr            @ persevere link reg across call
26     bl    lowlevel_init        @ go setup pll,mux,memory
27     mov    lr, ip            @ restore link
28     mov    pc, lr            @ back to my caller

15.找到lowlevel_init这个函数，E:\arm_a\IMX6_CoreC_CD\Linux 源码包\uboot源码\uboot_IMX6_CoreC_1.3.4_for_Linux\board\freescale\mx6q_sabresd\lowlevel_init.S

1 .globl lowlevel_init
2 lowlevel_init:
3     inv_dcache
4     init_l2cc
5     init_aips
6     init_clock
7     mov pc, lr

16. 接下来一个尴尬的问题，不知道程序接下来往哪里走了！！假设汇编代码是顺序执行的，那么接下来是relocate

 1 relocate:                @ relocate U-Boot to RAM
 2     adr    r0, _start        @ r0 <- current position of code
 3     ldr    r1, _TEXT_BASE        @ test if we run from flash or RAM
 4     cmp    r0, r1            @ don't reloc during debug
 5     beq    stack_setup
 6 
 7     ldr    r2, _armboot_start
 8     ldr    r3, _bss_start
 9     sub    r2, r3, r2        @ r2 <- size of armboot
10     add    r2, r0, r2        @ r2 <- source end address
11 
12 copy_loop:                @ copy 32 bytes at a time
13     ldmia    r0!, {r3 - r10}        @ copy from source address [r0]
14     stmia    r1!, {r3 - r10}        @ copy to   target address [r1]
15     cmp    r0, r2            @ until source end addreee [r2]
16     ble    copy_loop
17 #endif    /* CONFIG_SKIP_RELOCATE_UBOOT */
18 
19     /* Set up the stack */
20 stack_setup:
21     ldr    r0, _TEXT_BASE        @ upper 128 KiB: relocated uboot
22     sub    r0, r0, #CONFIG_SYS_MALLOC_LEN @ malloc area
23     sub    r0, r0, #CONFIG_SYS_GBL_DATA_SIZE @ bdinfo
24 #ifdef CONFIG_USE_IRQ
25     sub    r0, r0, #(CONFIG_STACKSIZE_IRQ + CONFIG_STACKSIZE_FIQ)
26 #endif
27     sub    sp, r0, #12        @ leave 3 words for abort-stack
28     and    sp, sp, #~7        @ 8 byte alinged for (ldr/str)d
29 
30     /* Clear BSS (if any). Is below tx (watch load addr - need space) */
31 clear_bss:
32     ldr    r0, _bss_start        @ find start of bss segment
33     ldr    r1, _bss_end        @ stop here
34     mov    r2, #0x00000000        @ clear value
35 clbss_l:
36     str    r2, [r0]        @ clear BSS location
37     cmp    r0, r1            @ are we at the end yet
38     add    r0, r0, #4        @ increment clear index pointer
39     bne    clbss_l            @ keep clearing till at end
40 
41 #ifdef CONFIG_ARCH_MMU
42     bl board_mmu_init
43 #endif
44     ldr    pc, _start_armboot    @ jump to C code
45 
46 _start_armboot: .word start_armboot

17. 跳入到C语言函数中start_armboot，但是这个函数在哪里？还好在书中找到了答案。uboot_IMX6_CoreC_1.3.4_for_Linux\lib_arm\board.c

  1 void start_armboot (void)
  2 {
  3     init_fnc_t **init_fnc_ptr;
  4     char *s;
  5 #if defined(CONFIG_VFD) || defined(CONFIG_LCD)
  6     unsigned long addr;
  7 #endif
  8 
  9     /* Pointer is writable since we allocated a register for it */
 10     gd = (gd_t*)(_armboot_start - CONFIG_SYS_MALLOC_LEN - sizeof(gd_t));
 11     /* compiler optimization barrier needed for GCC >= 3.4 */
 12     __asm__ __volatile__("": : :"memory");
 13 
 14     memset ((void*)gd, 0, sizeof (gd_t));
 15     gd->bd = (bd_t*)((char*)gd - sizeof(bd_t));
 16     memset (gd->bd, 0, sizeof (bd_t));
 17 
 18     gd->flags |= GD_FLG_RELOC;
 19 
 20     monitor_flash_len = _bss_start - _armboot_start;
 21 
 22     for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
 23         if ((*init_fnc_ptr)() != 0) {
 24             hang ();
 25         }
 26     }
 27 
 28     /* armboot_start is defined in the board-specific linker script */
 29     mem_malloc_init (_armboot_start - CONFIG_SYS_MALLOC_LEN);
 30 
 31 #ifndef CONFIG_SYS_NO_FLASH
 32     /* configure available FLASH banks */
 33     display_flash_config (flash_init ());
 34 #endif /* CONFIG_SYS_NO_FLASH */
 35 
 36 #ifdef CONFIG_VFD
 37 #    ifndef PAGE_SIZE
 38 #      define PAGE_SIZE 4096
 39 #    endif
 40     /*
 41      * reserve memory for VFD display (always full pages)
 42      */
 43     /* bss_end is defined in the board-specific linker script */
 44     addr = (_bss_end + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 45     vfd_setmem (addr);
 46     gd->fb_base = addr;
 47 #endif /* CONFIG_VFD */
 48 
 49 #ifdef CONFIG_LCD
 50     /* board init may have inited fb_base */
 51     if (!gd->fb_base) {
 52 #        ifndef PAGE_SIZE
 53 #          define PAGE_SIZE 4096
 54 #        endif
 55         /*
 56          * reserve memory for LCD display (always full pages)
 57          */
 58         /* bss_end is defined in the board-specific linker script */
 59         addr = (_bss_end + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
 60         lcd_setmem (addr);
 61         gd->fb_base = addr;
 62     }
 63 #endif /* CONFIG_LCD */
 64 
 65 #if defined(CONFIG_CMD_NAND)
 66     puts ("NAND:  ");
 67     nand_init();        /* go init the NAND */
 68 #endif
 69 
 70 #if defined(CONFIG_CMD_ONENAND)
 71     onenand_init();
 72 #endif
 73 
 74 #ifdef CONFIG_HAS_DATAFLASH
 75     AT91F_DataflashInit();
 76     dataflash_print_info();
 77 #endif
 78 
 79 #ifdef CONFIG_GENERIC_MMC
 80 #ifndef CONFIG_DIS_BOARD_INFO
 81     puts ("MMC:   ");
 82 #endif
 83     mmc_initialize (gd->bd);
 84 #endif
 85 
 86     /* initialize environment */
 87     env_relocate ();
 88 
 89 #ifdef CONFIG_VFD
 90     /* must do this after the framebuffer is allocated */
 91     drv_vfd_init();
 92 #endif /* CONFIG_VFD */
 93 
 94 #ifdef CONFIG_SERIAL_MULTI
 95     serial_initialize();
 96 #endif
 97 
 98     /* IP Address */
 99     gd->bd->bi_ip_addr = getenv_IPaddr ("ipaddr");
100 
101 #if defined CONFIG_SPLASH_SCREEN && defined CONFIG_VIDEO_MX5
102     setup_splash_image();
103 #endif
104 
105     stdio_init ();    /* get the devices list going. */
106 
107     jumptable_init ();
108 
109 #if defined(CONFIG_API)
110     /* Initialize API */
111     api_init ();
112 #endif
113 
114     console_init_r ();    /* fully init console as a device */
115 
116 #if defined(CONFIG_ARCH_MISC_INIT)
117     /* miscellaneous arch dependent initialisations */
118     arch_misc_init ();
119 #endif
120 #if defined(CONFIG_MISC_INIT_R)
121     /* miscellaneous platform dependent initialisations */
122     misc_init_r ();
123 #endif
124 
125     /* enable exceptions */
126     enable_interrupts ();
127 
128     /* Perform network card initialisation if necessary */
129 #ifdef CONFIG_DRIVER_TI_EMAC
130     /* XXX: this needs to be moved to board init */
131 extern void davinci_eth_set_mac_addr (const u_int8_t *addr);
132     if (getenv ("ethaddr")) {
133         uchar enetaddr[6];
134         eth_getenv_enetaddr("ethaddr", enetaddr);
135         davinci_eth_set_mac_addr(enetaddr);
136     }
137 #endif
138 
139 #ifdef CONFIG_DRIVER_CS8900
140     /* XXX: this needs to be moved to board init */
141     cs8900_get_enetaddr ();
142 #endif
143 
144 #if defined(CONFIG_DRIVER_SMC91111) || defined (CONFIG_DRIVER_LAN91C96)
145     /* XXX: this needs to be moved to board init */
146     if (getenv ("ethaddr")) {
147         uchar enetaddr[6];
148         eth_getenv_enetaddr("ethaddr", enetaddr);
149         smc_set_mac_addr(enetaddr);
150     }
151 #endif /* CONFIG_DRIVER_SMC91111 || CONFIG_DRIVER_LAN91C96 */
152 
153 #if defined(CONFIG_ENC28J60_ETH) && !defined(CONFIG_ETHADDR)
154     extern void enc_set_mac_addr (void);
155     enc_set_mac_addr ();
156 #endif /* CONFIG_ENC28J60_ETH && !CONFIG_ETHADDR*/
157 
158     /* Initialize from environment */
159     if ((s = getenv ("loadaddr")) != NULL) {
160         load_addr = simple_strtoul (s, NULL, 16);
161     }
162 #if defined(CONFIG_CMD_NET)
163     if ((s = getenv ("bootfile")) != NULL) {
164         copy_filename (BootFile, s, sizeof (BootFile));
165     }
166 #endif
167 
168 #ifdef BOARD_LATE_INIT
169     board_late_init ();
170 #endif
171 
172 #ifdef CONFIG_ANDROID_RECOVERY
173     check_recovery_mode();
174 #endif
175 
176 #if defined(CONFIG_CMD_NET)
177 #if defined(CONFIG_NET_MULTI)
178 #ifndef CONFIG_DIS_BOARD_INFO
179     puts ("Net:   ");
180 #endif
181 #endif
182     eth_initialize(gd->bd);
183 #if defined(CONFIG_RESET_PHY_R)
184     debug ("Reset Ethernet PHY\n");
185     reset_phy();
186 #endif
187 #endif
188 #ifdef CONFIG_FASTBOOT
189     check_fastboot_mode();
190 #endif
191     /* main_loop() can return to retry autoboot, if so just run it again. */
192     for (;;) {
193         main_loop ();
194     }
195 
196     /* NOTREACHED - no way out of command loop except booting */
197 }                            
//结束
posted @ 2017-12-22 19:42  429512065  阅读(3149)  评论(1)  编辑  收藏  举报