Dear Seunghyeon Rhee,
please do not top posting.
2009/11/5 "Seunghyeon Rhee (이승현)" seunghyeon@lpmtec.com:
Dear Minkyu Kang,
What causes the current ambiguity is, in my opinion, the "parameters" themselves and "the way of setting them." As you know, DRAM controller is integrated in the SoC while the parameters required to set them are dependent on the external components, DRAM chips.
In this respect, cpu_init.S - I don't like the name because all it does is set up the memory controller. mem_setup.S is more appropriate - don't need to be moved to board description stuffs. The memory controller (the hardware logic in the SoC) is not changeable according to the board design. Neither does the way of setting it, which is in charge of cpu_init.S. What is changed from board to board is not cpu_init.S but the parameters. If we move it to board directory, we have to add redundant code - actually several copies of the same file - every time we add support for a new board with the same SoC.
Thererfore, I think cpu_init.S(or mem_setup.S) would better be placed with SoC stuffs like it is now while DRAM parameters be moved to board description stuffs. We can make the function for setting up the DRAM controller completely independent of board design by introducing more macro definitions if necessary. All we have to do for adding support for new boards then will be reduced to creating the new board's description. No redundant codes, no repeated modification of the SoC description will be required.
Agreed. But, I'm not sure that move it to board configuration file. let's figure out and discuss.. including regard your suggestion.
Best regards, Seunghyeon
Seunghyeon Rhee, Ph.D. / Director LPM Technology Inc. T +82-70-8255-6007 F +82-2-6442-6462 M +82-10-2790-0657
Minkyu Kang 쓴 글:
Dear Seunghyeon Rhee,
2009/11/4 "Seunghyeon Rhee (이승현)" seunghyeon@lpmtec.com:
Move the definitions of DRAM parameters from SoC description (s3c6400.h) to board description (smdk6400.h). DRAM parameters are rather board-specific than SoC specific. According to the current source, one may have to change the definitions in s3c6400.h in addition to creating the new board description whenever he wants to add support for a new board based on s3c6400. I don't think this meets the U-Boot policy of separating SoC description and board description. There will be no observable changes in operation. It's just to make it easier to add support for new boards.
Signed-off-by: Seunghyeon Rhee seunghyeon@lpmtec.com
include/configs/smdk6400.h | 21 +++++++++++++++++++++ include/s3c6400.h | 21 --------------------- 2 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/include/configs/smdk6400.h b/include/configs/smdk6400.h index f6e1221..a2b46fd 100644 --- a/include/configs/smdk6400.h +++ b/include/configs/smdk6400.h @@ -309,4 +309,25 @@ # error "usb_ohci.c is currently broken with MMU enabled." #endif
+/*-----------------------------------------------------------------------
- Physical Memory Map
- */
+#define DMC1_MEM_CFG 0x80010012 /* Chip1, Burst4, Row/Column bit */ +#define DMC1_MEM_CFG2 0xB45 +#define DMC1_CHIP0_CFG 0x150F8 /* 0x4000_0000 ~ 0x43ff_ffff (64MB) */ +#define DMC_DDR_32_CFG 0x0 /* 32bit, DDR */
+/* Memory Parameters */ +/* DDR Parameters */ +#define DDR_tREFRESH 7800 /* ns */ +#define DDR_tRAS 45 /* ns (min: 45ns)*/ +#define DDR_tRC 68 /* ns (min: 67.5ns)*/ +#define DDR_tRCD 23 /* ns (min: 22.5ns)*/ +#define DDR_tRFC 80 /* ns (min: 80ns)*/ +#define DDR_tRP 23 /* ns (min: 22.5ns)*/ +#define DDR_tRRD 15 /* ns (min: 15ns)*/ +#define DDR_tWR 15 /* ns (min: 15ns)*/ +#define DDR_tXSR 120 /* ns (min: 120ns)*/ +#define DDR_CASL 3 /* CAS Latency 3 */
#endif /* __CONFIG_H */ diff --git a/include/s3c6400.h b/include/s3c6400.h index e527c08..34d0d15 100644 --- a/include/s3c6400.h +++ b/include/s3c6400.h @@ -814,27 +814,6 @@ #endif
-/*-----------------------------------------------------------------------
- Physical Memory Map
- */
-#define DMC1_MEM_CFG 0x80010012 /* Chip1, Burst4, Row/Column bit */ -#define DMC1_MEM_CFG2 0xB45 -#define DMC1_CHIP0_CFG 0x150F8 /* 0x4000_0000 ~ 0x43ff_ffff (64MB) */ -#define DMC_DDR_32_CFG 0x0 /* 32bit, DDR */
-/* Memory Parameters */ -/* DDR Parameters */ -#define DDR_tREFRESH 7800 /* ns */ -#define DDR_tRAS 45 /* ns (min: 45ns)*/ -#define DDR_tRC 68 /* ns (min: 67.5ns)*/ -#define DDR_tRCD 23 /* ns (min: 22.5ns)*/ -#define DDR_tRFC 80 /* ns (min: 80ns)*/ -#define DDR_tRP 23 /* ns (min: 22.5ns)*/ -#define DDR_tRRD 15 /* ns (min: 15ns)*/ -#define DDR_tWR 15 /* ns (min: 15ns)*/ -#define DDR_tXSR 120 /* ns (min: 120ns)*/ -#define DDR_CASL 3 /* CAS Latency 3 */
/*
- mDDR memory configuration
*/
1.6.2.5
-- Seunghyeon Rhee, Ph.D. / Director LPM Technology Inc. T +82-70-8255-6007 F +82-2-6442-6462 M +82-10-2790-0657 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
yes, DRAM parameters are board specific. But I think it is not good way to move DRAM parameters to board configuration file. At first, we need to move cpu/arm1176/s3c64xx/cpu_init.S to board directory. (please see smdkc100/mem_setup.S) And.. let's think about where to move DRAM parameters. Please give your opinion.
Thanks Minkyu Kang
U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Thanks Minkyu Kang