建立自己的开发板
在SMDK2410上移植, 交叉编译器：arm-linux-gcc—3.4.5
解压U-BOOT-1.1.6，进入U-BOOT目录，在board目录下，新建自己的开发板目录TX24x0，把smdk2410目录下的所有文件拷到TX24x0，把smdk2410.c改为 TX24X0.c。修改该目录下的Makefile，把smdk2410.o改为TX24x0.o。
COBJS := TX24X0.o flash.o
在include/configs目录下创建板子的配置头文件，把smdk2410.h改名为TX24x0.h，
修改顶层Makefile：
在smdk2410_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t smdk2410 NULL s3c24x0
加上
TX24x0_config : unconfig
@$(MKCONFIG) $(@:_config=) arm arm920t TX24X0 NULL s3c24x0
各项的意思如下:
arm: CPU的架构(ARCH)
arm920t: CPU的类型(CPU)，其对应于cpu/arm920t子目录。
TX24X0: 开发板的型号(BOARD)，对应于board/ TX24X0目录。
NULL: 开发者/或经销商(vender)。
s3c24x0: 片上系统(SOC)。
在第128行：
ifeq ($(ARCH),arm)
CROSS_COMPILE = arm-linux-
指定交叉编译器，这里也可以写绝对路径
修改SDRAM配置，在board/ TX24X0/lowlevel_init.S中，检查
#define B6_BWSCON (DW32) 位宽为32
把B1_BWSCON 改为（DW16） B5_BWSCON 改为（DW8）
根据HCLK设置SDRAM 的刷新参数，主要是REFCNT寄存器，开发板HCLK为100M
将 #define REFCNT 0x1113 改为 #define REFCNT 0x4f4
测试能否编译成功：
执行make TX24X0_config
出现make: execvp: …………/mkconfig: 权限不够
查看mkconfig的权限，发现没有可执行权限，用chmod 764 mkconfig加上权限
然后再make，成功后可出现 Configuring for TX24X0 board.....
增加对S3C2440的支持
2440的时钟计算公式、NAND操作和2410不太一样。
对于2440开发板，将FCLK设为400MHz，分频比为FCLK：HCLK：PCLK=1：4：8。
修改board/ TX24X0/ TX24X0.c中的board_init函数
/* S3C2440: Mpll,Upll = (2*m * Fin) / (p * 2^s)
* m = M (the value for divider M)+ 8, p = P (the value for divider P) + 2
*/
#define S3C2440_MPLL_400MHZ ((0x7f<<12)|(0x02<<4)|(0x01))
#define S3C2440_UPLL_48MHZ ((0x38<<12)|(0x02<<4)|(0x02))
#define S3C2440_CLKDIV 0x05 /* FCLK:HCLK:PCLK = 1:4:8 */
/* S3C2410: Mpll,Upll = (m * Fin) / (p * 2^s)
* m = M (the value for divider M)+ 8, p = P (the value for divider P) + 2
*/
#define S3C2410_MPLL_200MHZ ((0x5c<<12)|(0x04<<4)|(0x00))
#define S3C2410_UPLL_48MHZ ((0x28<<12)|(0x01<<4)|(0x02))
#define S3C2410_CLKDIV 0x03 /* FCLK:HCLK:PCLK = 1:2:4 */
int board_init (void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
/* set up the I/O ports */
gpio->GPACON = 0x007FFFFF;
gpio->GPBCON = 0x00044555;
gpio->GPBUP = 0x000007FF;
gpio->GPCCON = 0xAAAAAAAA;
gpio->GPCUP = 0x0000FFFF;
gpio->GPDCON = 0xAAAAAAAA;
gpio->GPDUP = 0x0000FFFF;
gpio->GPECON = 0xAAAAAAAA;
gpio->GPEUP = 0x0000FFFF;
gpio->GPFCON = 0x000055AA;
gpio->GPFUP = 0x000000FF;
gpio->GPGCON = 0xFF95FFBA;
gpio->GPGUP = 0x0000FFFF;
gpio->GPHCON = 0x002AFAAA;
gpio->GPHUP = 0x000007FF;
/*support both of S3C2410 and S3C2440*/
if ((gpio->GSTATUS1 == 0x32410000) || (gpio->GSTATUS1 == 0x32410002))
{
/*FCLK:HCLK:PCLK = 1:2:4*/
clk_power->CLKDIVN = S3C2410_CLKDIV;
/* change to asynchronous bus mod */
__asm__( "mrc p15, 0, r1, c1, c0, 0\n" /* read ctrl register */
"orr r1, r1, #0xc0000000\n" /* Asynchronous */
"mcr p15, 0, r1, c1, c0, 0\n" /* write ctrl register */
:::"r1"
);
/* to reduce PLL lock time, adjust the LOCKTIME register */
clk_power->LOCKTIME = 0xFFFFFF;
/* configure MPLL */
clk_power->MPLLCON = S3C2410_MPLL_200MHZ;
/* some delay between MPLL and UPLL */
delay (4000);
/* configure UPLL */
clk_power->UPLLCON = S3C2410_UPLL_48MHZ;
/* some delay between MPLL and UPLL */
delay (8000);
/* arch number of SMDK2410-Board */
gd->bd->bi_arch_number = MACH_TYPE_SMDK2410;
}
else
{
/* FCLK:HCLK:PCLK = 1:4:8 */
clk_power->CLKDIVN = S3C2440_CLKDIV;
/* change to asynchronous bus mod */
__asm__( "mrc p15, 0, r1, c1, c0, 0\n" /* read ctrl register */
"orr r1, r1, #0xc0000000\n" /* Asynchronous */
"mcr p15, 0, r1, c1, c0, 0\n" /* write ctrl register */
:::"r1"
);
/* to reduce PLL lock time, adjust the LOCKTIME register */
clk_power->LOCKTIME = 0xFFFFFF;
/* configure MPLL */
clk_power->MPLLCON = S3C2440_MPLL_400MHZ;
/* some delay between MPLL and UPLL */
delay (4000);
/* configure UPLL */
clk_power->UPLLCON = S3C2440_UPLL_48MHZ;
/* some delay between MPLL and UPLL */
delay (8000);
/* arch number of SMDK2440-Board */
gd->bd->bi_arch_number = MACH_TYPE_S3C2440;
}
/* adress of boot parameters */
gd->bd->bi_boot_params = 0x30000100;
icache_enable();
dcache_enable();
return 0;
}
在cpu/arm920t/s3c24X0/speed.c中修改：
在程序开头增加一行DECLARE_GLOBAL_DATA_PTR;，这样才可以使用gd变量
修改get_PLLCLK函数：
static ulong get_PLLCLK(int pllreg)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
ulong r, m, p, s;
if (pllreg == MPLL)
r = clk_power->MPLLCON;
else if (pllreg == UPLL)
r = clk_power->UPLLCON;
else
hang();
m = ((r & 0xFF000) >> 12) + 8;
p = ((r & 0x003F0) >> 4) + 2;
s = r & 0x3;
/* support both of S3C2410 and S3C2440 */
if (gd->bd->bi_arch_number == MACH_TYPE_SMDK2410)
return((CONFIG_SYS_CLK_FREQ * m) / (p << s));
else
return((CONFIG_SYS_CLK_FREQ * m * 2) / (p << s)); /* S3C2440 */
}
修改get_HCLK, get_PCLK:
/* for s3c2440 */
#define S3C2440_CLKDIVN_PDIVN (1<<0)
#define S3C2440_CLKDIVN_HDIVN_MASK (3<<1)
#define S3C2440_CLKDIVN_HDIVN_1 (0<<1)
#define S3C2440_CLKDIVN_HDIVN_2 (1<<1)
#define S3C2440_CLKDIVN_HDIVN_4_8 (2<<1)
#define S3C2440_CLKDIVN_HDIVN_3_6 (3<<1)
#define S3C2440_CLKDIVN_UCLK (1<<3)
#define S3C2440_CAMDIVN_CAMCLK_MASK (0xf<<0)
#define S3C2440_CAMDIVN_CAMCLK_SEL (1<<4)
#define S3C2440_CAMDIVN_HCLK3_HALF (1<<8)
#define S3C2440_CAMDIVN_HCLK4_HALF (1<<9)
#define S3C2440_CAMDIVN_DVSEN (1<<12)
/* return HCLK frequency */
ulong get_HCLK(void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
unsigned long clkdiv;
unsigned long camdiv;
int hdiv = 1;
/* support both of S3C2410 and S3C2440 */
if (gd->bd->bi_arch_number == MACH_TYPE_SMDK2410)
return((clk_power->CLKDIVN & 0x2) ? get_FCLK()/2 : get_FCLK());
else
{
clkdiv = clk_power->CLKDIVN;
camdiv = clk_power->CAMDIVN;
/* work out clock scalings */
switch (clkdiv & S3C2440_CLKDIVN_HDIVN_MASK) {
case S3C2440_CLKDIVN_HDIVN_1:
hdiv = 1;
break;
case S3C2440_CLKDIVN_HDIVN_2:
hdiv = 2;
break;
case S3C2440_CLKDIVN_HDIVN_4_8:
hdiv = (camdiv & S3C2440_CAMDIVN_HCLK4_HALF) ? 8 : 4;
break;
case S3C2440_CLKDIVN_HDIVN_3_6:
hdiv = (camdiv & S3C2440_CAMDIVN_HCLK3_HALF) ? 6 : 3;
break;
}
return get_FCLK() / hdiv;
}
}
/* return PCLK frequency */
ulong get_PCLK(void)
{
S3C24X0_CLOCK_POWER * const clk_power = S3C24X0_GetBase_CLOCK_POWER();
unsigned long clkdiv;
unsigned long camdiv;
int hdiv = 1;
/* support both of S3C2410 and S3C2440 */
if (gd->bd->bi_arch_number == MACH_TYPE_SMDK2410)
return((clk_power->CLKDIVN & 0x1) ? get_HCLK()/2 : get_HCLK());
else
{
clkdiv = clk_power->CLKDIVN;
camdiv = clk_power->CAMDIVN;
/* work out clock scalings */
switch (clkdiv & S3C2440_CLKDIVN_HDIVN_MASK) {
case S3C2440_CLKDIVN_HDIVN_1:
hdiv = 1;
break;
case S3C2440_CLKDIVN_HDIVN_2:
hdiv = 2;
break;
case S3C2440_CLKDIVN_HDIVN_4_8:
hdiv = (camdiv & S3C2440_CAMDIVN_HCLK4_HALF) ? 8 : 4;
break;
case S3C2440_CLKDIVN_HDIVN_3_6:
hdiv = (camdiv & S3C2440_CAMDIVN_HCLK3_HALF) ? 6 : 3;
break;
}
return get_FCLK() / hdiv / ((clkdiv & S3C2440_CLKDIVN_PDIVN)? 2:1);
}
}
执行
# make TX24X0_config
# make all
生成u-boot.bin，烧入NOR Flash中运行在make all时会出现错误：没有CAMDIVN这个要在include/s3c24x0.h中定义，在129行S3C24X0_CLOCK_POWER结构体中增加：S3C24X0_REG32 CAMDIVN; /* for s3c2440*/
至此，对S3C2440 的支持（时钟配置部分）就算做好了，为了方便调试，
可以利用开发板自带的u-boot 将u-boot.bin 文件烧到内存中运行，此时还要修改一些设置：
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