[U-Boot] Got u-boot-2012.10 running on at91sam9200 - but why does it work?
Hi,
I managed to get u-boot-2012.10 to boot from NOR flash on a custom at91rm9200 board by doing this:
Signed-off-by: Arvid Brodin arvid.brodin@xdin.com --- arch/arm/cpu/arm920t/start.S | 8 +++----- 2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S index 14c9156..efc4ea3 100644 --- a/arch/arm/cpu/arm920t/start.S +++ b/arch/arm/cpu/arm920t/start.S @@ -294,9 +294,7 @@ clbss_e: _nand_boot_ofs: .word nand_boot #else - ldr r0, _board_init_r_ofs - adr r1, _start - add lr, r0, r1 + ldr lr, _board_init_r add lr, lr, r9 /* setup parameters for board_init_r */ mov r0, r5 /* gd_t */ @@ -304,8 +302,8 @@ _nand_boot_ofs: /* jump to it ... */ mov pc, lr
-_board_init_r_ofs: - .word board_init_r - _start +_board_init_r: + .word board_init_r #endif
_rel_dyn_start_ofs:
Hello Arvid, Am 2013-10-09 21:23, schrieb Arvid Brodin:
Hi,
I managed to get u-boot-2012.10 to boot from NOR flash on a custom at91rm9200 board by doing this:
Signed-off-by: Arvid Brodin arvid.brodin@xdin.com
arch/arm/cpu/arm920t/start.S | 8 +++----- 2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S index 14c9156..efc4ea3 100644 --- a/arch/arm/cpu/arm920t/start.S +++ b/arch/arm/cpu/arm920t/start.S @@ -294,9 +294,7 @@ clbss_e: _nand_boot_ofs: .word nand_boot #else
- ldr r0, _board_init_r_ofs
- adr r1, _start
- add lr, r0, r1
- ldr lr, _board_init_r add lr, lr, r9 /* setup parameters for board_init_r */ mov r0, r5 /* gd_t */
@@ -304,8 +302,8 @@ _nand_boot_ofs: /* jump to it ... */ mov pc, lr
-_board_init_r_ofs:
- .word board_init_r - _start
+_board_init_r:
- .word board_init_r
#endif
_rel_dyn_start_ofs:
you don't need change start.s to boot from NOR. If shold set the #define CONFIG_SYS_TEXT_BASE 0x00000000
Please see the configuration for eb_cpux9k2 board. This board does boot from NOR with u-boot 2012.10.
BTW The release 2012.10 is out of date. You should upadte to the current one (2013.10-rc4)
Best regards
Jens
On 2013-10-10 10:25, Jens Scharsig wrote:
Hello Arvid, Am 2013-10-09 21:23, schrieb Arvid Brodin:
Hi,
I managed to get u-boot-2012.10 to boot from NOR flash on a custom at91rm9200 board by doing this:
Signed-off-by: Arvid Brodin arvid.brodin@xdin.com
arch/arm/cpu/arm920t/start.S | 8 +++----- 2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S index 14c9156..efc4ea3 100644 --- a/arch/arm/cpu/arm920t/start.S +++ b/arch/arm/cpu/arm920t/start.S @@ -294,9 +294,7 @@ clbss_e: _nand_boot_ofs: .word nand_boot #else
- ldr r0, _board_init_r_ofs
- adr r1, _start
- add lr, r0, r1
- ldr lr, _board_init_r add lr, lr, r9 /* setup parameters for board_init_r */ mov r0, r5 /* gd_t */
@@ -304,8 +302,8 @@ _nand_boot_ofs: /* jump to it ... */ mov pc, lr
-_board_init_r_ofs:
- .word board_init_r - _start
+_board_init_r:
- .word board_init_r
#endif
_rel_dyn_start_ofs:
you don't need change start.s to boot from NOR. If shold set the #define CONFIG_SYS_TEXT_BASE 0x00000000
But that's just the thing, I *do* need this change for the board to boot. CONFIG_SYS_TEXT_BASE is 0x10000000 (this is the base address for the flash memory).
Without my patch above, I only get this:
---------- U-Boot 2012.10 (Oct 09 2013 - 02:28:44)
DRAM: 64 MiB ----------
I thought this was a known problem with at91rm9200 booting from NOR flash? There's at least one other board that I know of with the same problem (the Artila Matrix-500).
Please see the configuration for eb_cpux9k2 board. This board does boot from NOR with u-boot 2012.10.
Hmm, you are right. This config does boot my card (after I modify it to suit, of course). Besides the different CONFIG_SYS_TEXT_BASE, I think the main differences to the at91rm9200ek config that I based my earlier config on are these things:
#define CONFIG_SYS_BOOT_SIZE 0x00 /* 0 KBytes */ #define CONFIG_SYS_U_BOOT_BASE PHYS_FLASH_1 #define CONFIG_SYS_U_BOOT_SIZE 0x60000 /* 384 KBytes */
None of these are declared in the at91rm9200ek config.
Unfortunately, I don't have an AT91RM9200EK card, so I can't test if the problem I ran in to exists for that card as well using the at91rm9200ek config.
Hello Arvid,
you don't need change start.s to boot from NOR. If shold set the #define CONFIG_SYS_TEXT_BASE 0x00000000
But that's just the thing, I *do* need this change for the board to boot. CONFIG_SYS_TEXT_BASE is 0x10000000 (this is the base address for the flash memory).
YES and NO: The nor is physical mapped to 0x1000000 that's right. But during boot from nor the Memory is also mapped to address 0x0. U-Boot is relocate to ram after ram init. The calculations of the reclocation process are based on "delta between PC and CONFIG_SYS_TEXT_BASE".
Without my patch above, I only get this:
U-Boot 2012.10 (Oct 09 2013 - 02:28:44)
DRAM: 64 MiB
So at this position u-boot try to jump to a wrong address or code in ram.
I thought this was a known problem with at91rm9200 booting from NOR flash? There's at least one other board that I know of with the same problem (the Artila Matrix-500).
Please see the configuration for eb_cpux9k2 board. This board does boot from NOR with u-boot 2012.10.
Hmm, you are right. This config does boot my card (after I modify it to suit, of course). Besides the different CONFIG_SYS_TEXT_BASE, I think the main differences to the at91rm9200ek config that I based my earlier config on are these things:
#define CONFIG_SYS_BOOT_SIZE 0x00 /* 0 KBytes */ #define CONFIG_SYS_U_BOOT_BASE PHYS_FLASH_1 #define CONFIG_SYS_U_BOOT_SIZE 0x60000 /* 384 KBytes */
None of these are declared in the at91rm9200ek config.
This are old items, which needs a clean up.
Regards Jens
participants (2)
-
Arvid Brodin -
Jens Scharsig