原文地址:http://blog.youkuaiyun.com/lightsoure/archive/2010/09/22/5900500.aspx
环境:S5PC100+android(UBOOT 1.3.4)
DDR2 256MB
由于DDR2相对于mobile ddR的低功耗优势,加上产品本身对功耗要求较高,所以需要使用DD2代替MOBILE DDR;
从/board/samsung/smdkc100下的UBOOT链表u-boot.LDS
- .text :
- {
- cpu/s5pc1xx/start.o (.text)
- cpu/s5pc1xx/s5pc100/cpu_init.o (.text)
- board/samsung/smdkc100/lowlevel_init.o (.text)
- cpu/s5pc1xx/onenand_cp.o (.text)
- cpu/s5pc1xx/nand_cp.o (.text)
- cpu/s5pc1xx/movi.o (.text)
- *(.text)
- }
可以知道UBOOT整个工作流程,很清晰。我们要做的应该是修改内存部分相关配置;
从START.S中
/*
* Go setup Memory and board specific bits prior to relocation.
*/
ldr sp, =0xd0036000 /* end of sram dedicated to u-boot */
sub sp, sp, #12 /* set stack */
mov fp, #0
bl lowlevel_init /* go setup pll,mux,memory */
以及lowlevel_init .S中
/* when we already run in ram, we don't need to relocate U-Boot.
* and actually, memory controller must be configured before U-Boot
* is running in ram.
*/
ldr r0, =0xff000fff
bic r1, pc, r0 /* r0 <- current base addr of code */
ldr r2, _TEXT_BASE /* r1 <- original base addr in ram */
bic r2, r2, r0 /* r0 <- current base addr of code */
cmp r1, r2 /* compare r0, r1 */
beq 1f /* r0 == r1 then skip sdram init */
/* init system clock */
bl system_clock_init
bl mem_ctrl_asm_init知道内存相关配置在CPU_INIT.S中,好吧,不罗嗦了。直接贴上配置:
step1:
- /************ DLL initialization *************/
- // ldr r1, =0x6A101000 @ Phycontrol0 DLL parameter setting
- ldr r1, =0x50101008 //added by S
- str r1, [r0, #DMC_PHYCONTROL0]
- //ldr r1, =0x000000F4 //added by S
- ldr r1, =0x000000F6 //added by S the last bit is 6 for ddr21
- str r1, [r0, #DMC_PHYCONTROL1]
- // ldr r1, =0x00000000 @Phycontrol2 DLL parameter setting
- ldr r1, =0x00000000 //added by S
- str r1, [r0, #DMC_PHYCONTROL2]
- // ldr r1, =0x6A101002 @DLL on
- ldr r1, =0x5010100a //added by S
- str r1, [r0, #DMC_PHYCONTROL0]
- // ldr r1, =0x6A101003 @Dll start
- ldr r1, =0x5010100b //added by S
- str r1, [r0, #DMC_PHYCONTROL0]
- ldr r2, = 0xE6000040 @DMC_PHYSTATUS0
- loop1:
- ldr r1, [r2] @Check DLL lock
- ands r1, r1, #4
- beq loop1
- ldr r1, [r2]
- mov r1, r1, LSR #(0x6)
- and r1, r1, #(0xff)
- mov r1, r1, LSL #(0x18)
- ldr r2, = 0xE6000018 @DMC_PHYCONTROL0
- ldr r3, [r2]
- bic r3, r3, #(0xff000000)
- orr r1, r3, r2
- str r1, [r2]
- // ldr r1, =0x6A101003 @Force Value locking
- ldr r1, =0x5010100b //added by S
- str r1, [r0, #DMC_PHYCONTROL0]
- // ldr r1, =0x6A101009 @Dll off
- ldr r1, =0x50101009 //added by S
- str r1, [r0, #DMC_PHYCONTROL0]
- #if 0
- ldr r1, =0x6A101000 @ Phycontrol0 DLL parameter setting
- str r1, [r0, #DMC_PHYCONTROL0]
- ldr r1, =0x00008484 @Phycontrol1 DLL parameter setting
- str r1, [r0, #DMC_PHYCONTROL1]
- ldr r1, =0x00000000 @Phycontrol2 DLL parameter setting
- str r1, [r0, #DMC_PHYCONTROL2]
- #endif
- /************ DLL initialization - END *************/
step1中需要注意的是:对于DDR2,手册上说明PHYCONTROL1后最后3位为0X110;
step2:
- //ldr r1, =0x0FF01010 @auto refresh off
- ldr r1, =0x0FF01010 //added S
- str r1, [r0, #DMC_CONCONTROL]
- //ldr r1, =0x00102100
- ldr r1, =0x00212400 //added by S
- str r1, [r0, #DMC_MEMCONTROL]
- ldr r1, =0x20f00313 //1CS 256MB0
- str r1, [r0, #DMC_MEMCONFIG0]
- ldr r1, =0x40f00313 //added by S
- str r1, [r0, #DMC_MEMCONFIG1]
- ldr r1, =0x20000000
- str r1, [r0, #DMC_PRECHCONFIG]
- ldr r1, =0x00100004 @ PwrdnConfig
- str r1, [r0, #DMC_PWRDNCONFIG
step2中需要注意的是:对于DDR2 与S5PC100来说 需要注意的是要与实际内存电路设计相关,我是32bit 两片内存并联,所以DDR2 对应一个CS为256MB,所以对于DMC_MEMCONFIG0来说chip_mask为f0;如果这里为f8则出现,UBOOT引导内核后,在内核的内存配置部分死掉等现象;
还有个部分:
对于这里的设置是否真的能影响功耗,这个还有待测试。
step3:
- /************ Timing Optimization *************/
- /************ DDR2_166MHz *************///
- // 7.8us*166MHz=0x50e
- ldr r1, =0x0000050E
- str r1, [r0, #DMC_TIMINGAREF]
- ldr r1, =0x16233288 //added bu S
- str r1, [r0, #DMC_TIMINGROW]
- ldr r1, =0x23250304 @Timing Data //added bu S
- str r1, [r0, #DMC_TIMINGDATA]
- ldr r1, =0x06c80232 @ Timing Power !!!!!!!!!!!!!!!
- str r1, [r0, #DMC_TIMINGPOWER]
这部分是要根据你的内存时序来设置的,与其他BOOT内存时序配置类似.
step4:
- /* Direct Command for LPDDR - *///added by S 2010.9.16
- /* chip0*/
- ldr r1, =0x07000000 @chip0 Deselect
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x01000000 @chip0 PALL
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00020000 @ chip0 EMRS2
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00030000 @ chip0 EMRS3
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00010400 @ EMRS1 (MEM DLL on, DQS# disable)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00000552 @ chip0 MRS (MEM DLL reset)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x01000000 @ chip0 chip0 PALL
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x05000000 @ chip0 chip0 REFA
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x05000000 @ chip0 chip0 REFA
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00000452 @ chip0 MRS (MEM DLL unreset), BL=4,CL=5
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00010780 @ chip0 EMRS1 (OCD default)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00010400 @ chip0 EMRS1 (OCD exit)
- str r1, [r0, #DMC_DIRECTCMD]
- /* chip1*/
- ldr r1, =0x07100000 @DirectCmd chip1 Deselect
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x01100000 @DirectCmd chip1 PALL
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00120000 @DirectCmd chip1 EMRS2
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00130000 @DirectCmd chip1 EMRS3
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00110440 @DirectCmd chip1 EMRS1 (MEM DLL on, DQS# disable)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00100552 @DirectCmd chip1 MRS (MEM DLL reset) CL=5, BL=4
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x01100000 @DirectCmd chip1 PALL
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x05100000 @DirectCmd chip1 REFA
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x05100000 @DirectCmd chip1 REFA
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00100452 @DirectCmd chip1 MRS (MEM DLL unreset)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00110780 @DirectCmd chip1 EMRS1 (OCD default)
- str r1, [r0, #DMC_DIRECTCMD]
- ldr r1, =0x00110400 @DirectCmd chip1 EMRS1 (OCD exit)
- str r1, [r0, #DMC_DIRECTCMD]
- /***************************end**********************************
既然前面用到了两个片选则,对两个片选的配置。
step5: Start the DMC.
- // [ 5. Start the DMC.]//added by S
- ldr r1, =0x0FF020B0 //change S @ConControl auto refresh on
- str r1, [r0, #DMC_CONCONTROL]
- #if 0
- ldr r1, =0x001000FF @ PwrdnConfig
- str r1, [r0, #DMC_PWRDNCONFIG]
- #endif
- ldr r1, =0x00212413 //change S @ MemControl
- str r1, [r0, #DMC_MEMCONTROL]
- b exit_cpu_init
启动DMC
到这里这个流程基本结束了,因为没用ONENAND 所以着部分不用关注暂时
经过测试UBOOT能正常引导整个内核以及文件系统。
不过有个疑问:
我是8个BANKS,但是我选2个chips没有问题哦暂时,改成0X00貌似也一样。。这里有点晕忽~
留点疑问吧~等后面再侃侃~