移植Goni最方便的地方就是串口移植。
1.修改配置
include/configs/smart210.h
#define CONFIG_SERIAL2 1 /* use SERIAL2 */修改成SERIAL0
2.vim arch/arm/lib/crt0.S
- bl board_init_f
+ ldr lr, =_run_in_ram
+ ldr pc, =board_init_f
+_run_in_ram:3.lowlevel_init.S
3.1 时钟设置
/*
* system_clock_init: Initialize core clock and bus clock.
* void system_clock_init(void)
*/
system_clock_init:
ldr r0, =S5PC110_CLOCK_BASE @ 0xE0100000
ldr r0, =0xE010C000 @ S5PC110_PWR_CFG
/* Set OSC_FREQ value */
ldr r1, =0xf
str r1, [r0, #0x100] @ S5PC110_OSC_FREQ
/* Set MTC_STABLE value */
ldr r1, =0xffffffff
str r1, [r0, #0x110] @ S5PC110_MTC_STABLE
/* Set CLAMP_STABLE value */
ldr r1, =0x3ff03ff
str r1, [r0, #0x114] @ S5PC110_CLAMP_STABLE
ldr r0, =S5PC110_CLOCK_BASE @ 0xE0100000
/* Set Clock divider */
ldr r1, =0x14131440 @ 1:1:4:4, 1:4:5
str r1, [r0, #0x300]
ldr r1, =0x11110111 @ UART[3210]: MMC[3210]
str r1, [r0, #0x310]
/* Set Lock Time */
ldr r1, =0x2cf @ Locktime : 30us
str r1, [r0, #0x000] @ S5PC110_APLL_LOCK
ldr r1, =0xe10 @ Locktime : 0xe10 = 3600
str r1, [r0, #0x008] @ S5PC110_MPLL_LOCK
str r1, [r0, #0x010] @ S5PC110_EPLL_LOCK
str r1, [r0, #0x020] @ S5PC110_VPLL_LOCK
/* S5PC110_APLL_CON */
ldr r1, =0x807D0301 @ 1000MHz
str r1, [r0, #0x100]
/* S5PC110_MPLL_CON */
ldr r1, =0x829B0C01 @ 667MHz
str r1, [r0, #0x108]
/* S5PC110_EPLL_CON */
ldr r1, =0x80600602 @ 96MHz VSEL 0 P 6 M 96 S 2
str r1, [r0, #0x110]
/* S5PC110_VPLL_CON */
ldr r1, =0x806C0603 @ 54MHz
str r1, [r0, #0x120]
/* Set Source Clock */
ldr r1, =0x10001111 @ A, M, E, VPLL Muxing
str r1, [r0, #0x200] @ S5PC1XX_CLK_SRC0
/*
/* OneDRAM(DMC0) clock setting */
ldr r1, =0x01000000 @ ONEDRAM_SEL[25:24] 1 SCLKMPLL
str r1, [r0, #0x218] @ S5PC110_CLK_SRC6
ldr r1, =0x30000000 @ ONEDRAM_RATIO[31:28] 3 + 1
str r1, [r0, #0x318] @ S5PC110_CLK_DIV6
/* XCLKOUT = XUSBXTI 24MHz */
add r2, r0, #0xE000 @ S5PC110_OTHERS
ldr r1, [r2]
orr r1, r1, #(0x3 << 8) @ CLKOUT[9:8] 3 XUSBXTI
str r1, [r2]
/* wait at least 200us to stablize all clock */
mov r2, #0x10000
1: subs r2, r2, #1
bne 1b
mov pc, lr
3.2 DDR设置
3.3 copy_code_to_dram
4.copy_code_to_dram(mmc_relocate.c)
此时，烧录有输出：
U-Boot 2014.04 (Dec 23 2018 - 20:03:21)
CPU: S5PC110@1000MHz
Board: Goni
I2C: ready
DRAM: 3.9 GiB