u-boot-在2440上的移植詳解（二）
嵌入式Linux之我行，主要講述和總結(jié)了本人在學(xué)習(xí)嵌入式linux中的每個(gè)步驟。一為總結(jié)經(jīng)驗(yàn)，二希望能給想入門嵌入式Linux的朋友提供方便。如有錯(cuò)誤之處，謝請(qǐng)指正。
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一、移植環(huán)境
主 機(jī)：VMWare--Fedora 9
開發(fā)板：Mini2440--64MB Nand,Kernel:2.6.30.4
編譯器：arm-linux-gcc-4.3.2.tgz
u-boot：u-boot-2009.08.tar.bz2
二、移植步驟
上接：u-boot-2009.08在2440上的移植詳解（一）
4）準(zhǔn)備進(jìn)入u-boot的第二階段（在u-boot中添加對(duì)我們開發(fā)板上Nor Flash的支持）。
通 常，在嵌入式bootloader中，有兩種方式來(lái)引導(dǎo)啟動(dòng)內(nèi)核：從Nor Flash啟動(dòng)和從Nand Flash啟動(dòng)。u-boot中默認(rèn)是從Nor Flash啟動(dòng)，再?gòu)纳弦还?jié)這個(gè)運(yùn)行結(jié)果圖中看，還發(fā)現(xiàn)幾個(gè)問(wèn)題：第一，我開發(fā)板的Nor Flash是2M的，而這里顯示的是512kB；第二，出現(xiàn)Warning - bad CRC, using default environment的警告信息。不是u-boot默認(rèn)是從Nor Flash啟動(dòng)的嗎？為什么會(huì)有這些錯(cuò)誤信息呢？這是因?yàn)槲覀冞€沒(méi)有添加對(duì)我們自己的Nor Flash的支持，u-boot默認(rèn)的是其他型號(hào)的Nor Flash，而我們的Nor Flash的型號(hào)是SST39VF1601。另外怎樣將命令行提示符前面的SMDK2410變成我自己定義的呢？
下面我們一一來(lái)解決這些問(wèn)題，讓u-boot完全對(duì)我們Nor Flash的支持。首先我們修改頭文件代碼如下：
#geditinclude/configs/my2440.h//修改命令行前的名字和Nor Flash參數(shù)部分的定義
#defineCONFIG_SYS_PROMPT"[MY2440]#"http://將命令行前的名字改成[MY2440]
/*-----------------------------------------------------------------------
* FLASH and environment organization
*/
#if0//注釋掉下面兩個(gè)類型的Nor Flash設(shè)置，因?yàn)椴皇俏覀兯褂玫男吞?hào)
#defineCONFIG_AMD_LV4001/* uncomment this if you have a LV400 flash */
#defineCONFIG_AMD_LV8001/* uncomment this if you have a LV800 flash */
#endif
#defineCONFIG_SYS_MAX_FLASH_BANKS1/* max number of memory banks */
#ifdefCONFIG_AMD_LV800
#definePHYS_FLASH_SIZE0x00100000/* 1MB */
#defineCONFIG_SYS_MAX_FLASH_SECT(19)/* max number of sectors on one chip */
#defineCONFIG_ENV_ADDR(CONFIG_SYS_FLASH_BASE+0x0F0000)/* addr of environment */
#endif
#ifdefCONFIG_AMD_LV400
#definePHYS_FLASH_SIZE0x00080000/* 512KB */
#defineCONFIG_SYS_MAX_FLASH_SECT(11)/* max number of sectors on one chip */
#defineCONFIG_ENV_ADDR(CONFIG_SYS_FLASH_BASE+0x070000)/* addr of environment */
#endif
#defineCONFIG_SST_39VF16011//添加mini2440開發(fā)板Nor Flash設(shè)置
#definePHYS_FLASH_SIZE0x200000//我們開發(fā)板的Nor Flash是2M
#defineCONFIG_SYS_MAX_FLASH_SECT(512)//根據(jù)SST39VF1601的芯片手冊(cè)描述，對(duì)其進(jìn)行操作有兩種方式：塊方式和扇區(qū)方式?，F(xiàn)采用扇區(qū)方式(sector)，1 sector = 2Kword = 4Kbyte，所以2M的Nor Flash共有512個(gè)sector
#defineCONFIG_ENV_ADDR(CONFIG_SYS_FLASH_BASE+0x040000)//暫設(shè)置環(huán)境變量的首地址為0x040000(即：256Kb)
然后添加對(duì)我們mini2440開發(fā)板上2M的Nor Flash(型號(hào)為SST39VF1601)的支持。在u-boot中對(duì)Nor Flash的操作分別有初始化、擦除和寫入，所以我們主要修改與硬件密切相關(guān)的三個(gè)函數(shù)flash_init、flash_erase、 write_hword，修改代碼如下：
#geditboard/samsung/my2440/flash.c
//修改定義部分如下：
//#define MAIN_SECT_SIZE0x10000
#defineMAIN_SECT_SIZE0x1000//定義為4k，剛好是一個(gè)扇區(qū)的大小
//#define MEM_FLASH_ADDR1 (*(volatile u16 *)(CONFIG_SYS_FLASH_BASE + (0x00000555 << 1)))
//#define MEM_FLASH_ADDR2(*(volatile u16 *)(CONFIG_SYS_FLASH_BASE + (0x000002AA << 1)))
#defineMEM_FLASH_ADDR1(*(volatileu16*)(CONFIG_SYS_FLASH_BASE+(0x00005555<<1)))//這兩個(gè)參數(shù)看SST39VF1601手冊(cè)
#defineMEM_FLASH_ADDR2(*(volatileu16*)(CONFIG_SYS_FLASH_BASE+(0x00002AAA<<1)))
//修改flash_init函數(shù)如下：
#elifdefined(CONFIG_AMD_LV800)
(AMD_MANUFACT&FLASH_VENDMASK)|
(AMD_ID_LV800B&FLASH_TYPEMASK);
#elifdefined(CONFIG_SST_39VF1601)//在CONFIG_AMD_LV800后面添加CONFIG_SST_39VF1601
(SST_MANUFACT&FLASH_VENDMASK)|
(SST_ID_xF1601&FLASH_TYPEMASK);
for(j=0;j
// /* 1st one is 16 KB */
//if (j == 0) {
//flash_info[i].start[j] =flashbase + 0;
//}
///* 2nd and 3rd are both 8 KB */
//if ((j == 1) || (j == 2)) {
//flash_info[i].start[j] =flashbase + 0x4000 + (j -1) *0x2000;
//}
///* 4th 32 KB */
//if (j == 3) {
//flash_info[i].start[j] =flashbase + 0x8000;
//}
//} else {
//flash_info[i].start[j] =flashbase + (j - 3) * MAIN_SECT_SIZE;
//}
flash_info[i].start[j]=flashbase+j*MAIN_SECT_SIZE;
}
//修改flash_print_info函數(shù)如下：
case(AMD_MANUFACT&FLASH_VENDMASK):
printf("AMD: ");
break;
case(SST_MANUFACT&FLASH_VENDMASK)://添加SST39VF1601的
printf("SST:");
break;
case(AMD_ID_LV800B&FLASH_TYPEMASK):
printf("1x Amd29LV800BB (8Mbit)n");
break;
case(SST_ID_xF1601&FLASH_TYPEMASK)://添加SST39VF1601的
printf("1x SST39VF1610 (16Mbit)n");
break;
//修改flash_erase函數(shù)如下：
//if ((info->flash_id & FLASH_VENDMASK) !=
// (AMD_MANUFACT & FLASH_VENDMASK)) {
//return ERR_UNKNOWN_FLASH_VENDOR;
//}
if((info->flash_id&FLASH_VENDMASK)!=
(SST_MANUFACT&FLASH_VENDMASK)){
returnERR_UNKNOWN_FLASH_VENDOR;
}
///* wait until flash is ready */
//chip = 0;
//do {
//result = *addr;
///* check timeout */
//if (get_timer_masked () >
// CONFIG_SYS_FLASH_ERASE_TOUT) {
//MEM_FLASH_ADDR1 = CMD_READ_ARRAY;
//chip = TMO;
//break;
//}
//if (!chip
// && (result & 0xFFFF) & BIT_ERASE_DONE)
//chip = READY;
//if (!chip
// && (result & 0xFFFF) & BIT_PROGRAM_ERROR)
//chip = ERR;
//} while (!chip);
//MEM_FLASH_ADDR1 = CMD_READ_ARRAY;
//if (chip == ERR) {
//rc = ERR_PROG_ERROR;
//goto outahere;
//}
//if (chip == TMO) {
//rc = ERR_TIMOUT;
//goto outahere;
//}
while(1)
{
if((*addr&0x40)!=(*addr&0x40))
continue;
if(*addr&0x80)
{
rc=ERR_OK;
break;
}
}
//修改write_hword函數(shù)如下：
MEM_FLASH_ADDR1=CMD_UNLOCK1;
MEM_FLASH_ADDR2=CMD_UNLOCK2;
//MEM_FLASH_ADDR1 = CMD_UNLOCK_BYPASS;
MEM_FLASH_ADDR1=CMD_PROGRAM;
//*addr = CMD_PROGRAM;
*addr=data;
///* wait until flash is ready */
//chip = 0;
//do {
//result = *addr;
///* check timeout */
//if (get_timer_masked () > CONFIG_SYS_FLASH_ERASE_TOUT) {
//chip = ERR | TMO;
//break;
//}
//if (!chip && ((result & 0x80) == (data & 0x80)))
//chip = READY;
//if (!chip && ((result & 0xFFFF) & BIT_PROGRAM_ERROR)) {
//result = *addr;
//if ((result & 0x80) == (data & 0x80))
//chip = READY;
//else
//chip = ERR;
//}
//} while (!chip);
//*addr = CMD_READ_ARRAY;
//if (chip == ERR || *addr != data)
//rc = ERR_PROG_ERROR;
while(1)
{
if((*addr&0x40)!=(*addr&0x40))
continue;
if((*addr&0x80)==(data&0x80))
{
rc=ERR_OK;
break;
}
}
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