android移植（一）-s3c2416内核的移植
板子helper2416 芯片是三星的s3c2416 arm平台 本机系统： opensuse
以下只是记录曾经的瞎搞过程，可能有些乱。 要在板子上运行andoid首先得有一个支持android的内核
下载内核
$ git clone https://android.googlesource.com/kernel/samsung.git$ ls -a
. .. .git
$ git branch -r
origin/HEAD -> origin/master
origin/android-samsung-2.6.35-gingerbread
origin/android-samsung-3.0-ics-mr1
origin/master
$ git checkout origin/android-samsung-3.0-ics-mr1
hecking out files: 100% (37465/37465), done.
Previous HEAD position was eef8e7b... empty commit
HEAD is now at 6656123... ARM: s5pv210: herring: don't disable prox sensor during suspend
$ ls
arch CREDITS drivers include Kbuild lib mm REPORTING-BUGS security usr
block crypto firmware init Kconfig MAINTAINERS net samples sound virt
COPYING Documentation fs ipc kernel Makefile README scripts tools
上面版本为 3.0.8
由help2416的内核与同版本的内核比较，生成patch，然后把patch打到下载的android 内核上，冲突的手动解决
编译通过后，启动出现
Memory policy: ECC disabled, Data cache writeback
<4>BUG: not creating mapping for 0x56000000 at 0x03000000 in user region
Linux内核访问外设I/O内存资源的方式有两种：动态映射(ioremap)和静态映射(map_desc)
static void __init create_mapping(struct map_desc *md)
{
unsigned long addr, length, end;
phys_addr_t phys;
const struct mem_type *type;
pgd_t *pgd;
if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) { //0x03000000这个是virtual找到对应这个就能知道哪里错
printk(KERN_WARNING "BUG: not creating mapping for 0x%08llx"
" at 0x%08lx in user region\n",
(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
return;
}
.................
}
arch/arm/mach-s3c2416/s3c2416.c
static struct map_desc s3c2416_iodesc[] __initdata = {
IODESC_ENT(WATCHDOG),
IODESC_ENT(CLKPWR),
IODESC_ENT(TIMER),
};
iotable_init(s3c2416_iodesc, ARRAY_SIZE(s3c2416_iodesc));
struct map_desc {
unsigned long virtual; ////0x03000000
unsigned long pfn; //0x56000000 这两个值是出错值
unsigned long length;
unsigned int type;
};
#define IODESC_ENT(x) { (unsigned long)S3C24XX_VA_##x, __phys_to_pfn(S3C24XX_PA_##x), S3C24XX_SZ_##x, MT_DEVICE }
由代码可知，可能是S3C24XX_VA_WATCHDOG/CLKPWR/TIMER 中的一个或几个值不对 或者是S3C24XX_PA_xx中某个不对
另外还有一处可能是出错处
arm/mach-s3c2416/mach-smdk2416.c
static void __init smdk2416_map_io(void)
{
s3c24xx_init_io(smdk2416_iodesc, ARRAY_SIZE(smdk2416_iodesc)); //这个函数里处理了smdk2416_iodesc还处理了s3c_iodesc
}
static struct map_desc s3c_iodesc[] __initdata = {
IODESC_ENT(GPIO),
IODESC_ENT(IRQ),
IODESC_ENT(MEMCTRL),
IODESC_ENT(UART)
};
调试发现，出错出为GPIO处
#define S3C2410_PA_GPIO (0x56000000)
#define S3C24XX_VA_GPIO ((S3C24XX_PA_GPIO - S3C24XX_PA_UART) + S3C24XX_VA_UART)
#define S3C24XX_SZ_GPIO SZ_1M
S3C24XX_VA_GPIO = (0x56000000 - 0x50000000) + (0xFC000000 + 0x01000000) = 0x03000000
解决方法
arch/arm/plat-samsung/include/plat/map-base.h
#define S3C_ADDR_BASE (0xFC000000)
改成
#define S3C_ADDR_BASE 0xF6000000
另外启动时发现，打印信息都会打两次
比如
<6>usbcore: registered new interface driver usbfs
usbcore: registered new interface driver usbfs
查看printk源码
在vprintk中多了以下代码
#ifdef CONFIG_DEBUG_LL
printascii(printk_buf);
#endif
menuconfig中下面选项不配置
[ ] Kernel low-level debugging functions
=======================================================================================
kernel运行声卡驱动出问题
Error: Driver 'samsung-audio' is already registered, aborting...
ALSA device list:
No soundcards found.
搜索发现有两处driver的 name都是"samsung-audio",而且这两个driver都编译进内核，导致冲突
sound/soc/samsung/dma.c
sound/soc/samsung/s3c-dma-wrapper.c
sound/soc/samsung/Makefile
snd-soc-s3c24xx-objs := dma.o s3c-dma-wrapper.o
改成snd-soc-s3c24xx-objs := dma.o
此时还是无法识别声卡
sound/soc/samsung/dma.c
#ifndef CONFIG_S5P_INTERNAL_DMA //这行去掉
static int __devinit samsung_asoc_platform_probe(struct platform_device *pdev)
{
return snd_soc_register_platform(&pdev->dev, &samsung_asoc_platform);
}
.......
#endif //这行去掉
sound/soc/codecs/wm8753.c
static struct i2c_driver wm8753_i2c_driver = {
.driver = {
.name = "wm8753-codec", //注意这里与3.2.11不同
.owner = THIS_MODULE,
.........
}
/sound/soc/samsung/smdk2416_wm8753.c
static struct snd_soc_dai_link smdk6400_dai[] = {
{ /* Hifi Playback - for similatious use with voice below */
.name = "WM8753",
.stream_name = "WM8753 HiFi",
//.cpu_dai = &s3c_i2s_dai,
//.codec_dai = &wm8753_dai[WM8753_DAI_HIFI],
.platform_name = "samsung-audio",
.cpu_dai_name = "s3c24xx-iis",
.codec_dai_name = "wm8753-hifi",
.codec_name = "wm8753-codec.0-001a", //"wm8753.0-001a", //相应改这里
.init = smdk6400_wm8753_init,
.ops = &smdk6400_hifi_ops,
},
};
再编译运行kernel打印出错
clk_get: could not find clock iis for dev 0xc03e9f38 (s3c24xx-iis)
arch/arm/plat-s3c24xx/s3c2443-clock.c
static struct clk init_clocks_off[] = {
//加上
{
.name = "iis", //这个是针对s3c24xx-iis的
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_IIS,
}, {
.name = "hsspi", //这个是spi的,跟上面的错误无关，随便加的
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_HSSPI,
},
}
arch/arm/mach-s3c2410/include/mach/regs-s3c2443-clock.h
加上
#define S3C2443_PCLKCON_HSSPI (1<<6)
选中Android内核必须选项
Kernel Features ---> [*] Use the ARM EABI to compile the kernel
Device Drivers ---> [*] Staging drivers ---> Android --->
[*] Android Drivers
[*] Android Binder IPC Driver
<*> Android log driver
[*] Android RAM buffer console
[*] Enable verbose console messages on Android RAM console (NEW)
[*] Android RAM Console Enable error correction --->
[ ] Start Android RAM console early (NEW)
[*] Timed output class driver (NEW)
<*> Android timed gpio driver
[*] Android Low Memory Killer
-> General setup--> [ ] Configure standard kernel features (expert users) --->
-> General setup-->[*]Enable the Anonymous Shared Memory Subsystem
-> System Type-->[*]Support Thumb user binaries
作者：帅得不敢出门 c++哈哈堂群：31843264 转载请保留此信息