[U-Boot] [RFC] ARM: mx31pdk: Use the new relocation scheme

Hi,
I am trying to make the new relocation scheme to work on the mx31pdk board.
With this patch applied the mx31pdk build works, but not able to get a U-boot prompt yet.
I copied the nand_spl/board/karo/tx25/u-boot.lds to the mx31pdk one.
I am not certain whether the CONFIG_SYS_TEXT_BASE should be changed or not:
ifdef CONFIG_NAND_SPL CONFIG_SYS_TEXT_BASE = 0x87ec0000 else CONFIG_SYS_TEXT_BASE = 0x87f00000 endif
If anyone has any comments/suggestions I will appreciate it.
Thanks,
Fabio Estevam
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- arch/arm/cpu/arm1136/start.S | 4 +- board/freescale/mx31pdk/mx31pdk.c | 10 ++++- include/configs/mx31pdk.h | 6 +++ nand_spl/board/freescale/mx31pdk/u-boot.lds | 59 +++++++++++++++++++++++--- 4 files changed, 68 insertions(+), 11 deletions(-)
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 9a6f6cb..85b5e44 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -271,8 +271,8 @@ clbss_l:str r2, [r0] /* clear loop... */ ldr r0, _nand_boot_ofs adr r1, _start add pc, r0, r1 -_nand_boot_ofs - : .word nand_boot - _start +_nand_boot_ofs: + .word nand_boot - _start #else jump_2_ram: ldr r0, _board_init_r_ofs diff --git a/board/freescale/mx31pdk/mx31pdk.c b/board/freescale/mx31pdk/mx31pdk.c index 9f47169..2756e5a 100644 --- a/board/freescale/mx31pdk/mx31pdk.c +++ b/board/freescale/mx31pdk/mx31pdk.c @@ -33,10 +33,16 @@ DECLARE_GLOBAL_DATA_PTR;
int dram_init(void) { + /* dram_init must store complete ramsize in gd->ram_size */ + gd->ram_size = get_ram_size((volatile void *)CONFIG_SYS_SDRAM_BASE, + PHYS_SDRAM_1_SIZE); + return 0; +} + +void dram_init_banksize(void) +{ gd->bd->bi_dram[0].start = PHYS_SDRAM_1; gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE; - - return 0; }
int board_init(void) diff --git a/include/configs/mx31pdk.h b/include/configs/mx31pdk.h index 3b90a01..e3f8b9f 100644 --- a/include/configs/mx31pdk.h +++ b/include/configs/mx31pdk.h @@ -155,6 +155,12 @@ #define PHYS_SDRAM_1 CSD0_BASE #define PHYS_SDRAM_1_SIZE (128 * 1024 * 1024)
+#define CONFIG_SYS_SDRAM_BASE PHYS_SDRAM_1 +#define CONFIG_SYS_INIT_RAM_ADDR IRAM_BASE_ADDR +#define CONFIG_SYS_INIT_RAM_SIZE IRAM_SIZE +#define CONFIG_SYS_GBL_DATA_OFFSET (CONFIG_SYS_INIT_RAM_SIZE - GENERATED_GBL_DATA_SIZE) +#define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET) + /*----------------------------------------------------------------------- * FLASH and environment organization */ diff --git a/nand_spl/board/freescale/mx31pdk/u-boot.lds b/nand_spl/board/freescale/mx31pdk/u-boot.lds index edd8430..ff289fb 100644 --- a/nand_spl/board/freescale/mx31pdk/u-boot.lds +++ b/nand_spl/board/freescale/mx31pdk/u-boot.lds @@ -1,3 +1,25 @@ +/* + * (C) Copyright 2009 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm") OUTPUT_ARCH(arm) ENTRY(_start) @@ -19,18 +41,41 @@ SECTIONS .rodata : { *(.rodata) }
. = ALIGN(4); - .data : { *(.data) } + .data : { + *(.data) + }
. = ALIGN(4); - .got : { *(.got) } - - . = .; __u_boot_cmd_start = .; .u_boot_cmd : { *(.u_boot_cmd) } __u_boot_cmd_end = .;
. = ALIGN(4); - __bss_start = .; - .bss : { *(.bss) } - _end = .; + + .rel.dyn : { + __rel_dyn_start = .; + *(.rel*) + __rel_dyn_end = .; + } + + .dynsym : { + __dynsym_start = .; + *(.dynsym) + } + + .bss __rel_dyn_start (OVERLAY) : { + __bss_start = .; + *(.bss) + . = ALIGN(4); + _end = .; + } + + /DISCARD/ : { *(.bss*) } + /DISCARD/ : { *(.dynstr*) } + /DISCARD/ : { *(.dynsym*) } + /DISCARD/ : { *(.dynamic*) } + /DISCARD/ : { *(.hash*) } + /DISCARD/ : { *(.plt*) } + /DISCARD/ : { *(.interp*) } + /DISCARD/ : { *(.gnu*) } }

On 01/12/2011 01:49 PM, Fabio Estevam wrote:
Hi,
Hi Fabio,
I am trying to make the new relocation scheme to work on the mx31pdk board.
With this patch applied the mx31pdk build works, but not able to get a U-boot prompt yet.
I have tried to imagine some issues, but I cannot find a clear reason. Building with your patch I checked that nand_spl is still less than 2KB code, and that matches the NAND page, as required by i.MX31 - so it is not a problem.
Have you tried to disable the relocation, just to check if the relocation is an issue with CONFIG_SKIP_RELOCATE_UBOOT ? This is not a solution, but only to check what happens.
I copied the nand_spl/board/karo/tx25/u-boot.lds to the mx31pdk one.
I am not certain whether the CONFIG_SYS_TEXT_BASE should be changed or not:
ifdef CONFIG_NAND_SPL CONFIG_SYS_TEXT_BASE = 0x87ec0000 else CONFIG_SYS_TEXT_BASE = 0x87f00000 endif
I think they are ok - both addresses are valid RAM addresses. The relocation will move then the code at the end of the RAM. And as I understood from i.MX31 manual, the NFC controller does not use the IRAM at all, so the area pointed by your starting stack pointer should not be overwritten.
If anyone has any comments/suggestions I will appreciate it.
No great idea, really. Probably you need to attach a JTAG debugger and see what happens.
Best regards, Stefano Babic

Hi Stefano,
On 1/13/2011 11:38 AM, Stefano Babic wrote:
On 01/12/2011 01:49 PM, Fabio Estevam wrote:
Hi,
Hi Fabio,
I am trying to make the new relocation scheme to work on the mx31pdk board.
With this patch applied the mx31pdk build works, but not able to get a U-boot prompt yet.
I have tried to imagine some issues, but I cannot find a clear reason. Building with your patch I checked that nand_spl is still less than 2KB code, and that matches the NAND page, as required by i.MX31 - so it is not a problem.
Have you tried to disable the relocation, just to check if the relocation is an issue with CONFIG_SKIP_RELOCATE_UBOOT ? This is not a solution, but only to check what happens.
Yes, I tried to disable relocation and U-boot still fails to boot.
I copied the nand_spl/board/karo/tx25/u-boot.lds to the mx31pdk one.
I am not certain whether the CONFIG_SYS_TEXT_BASE should be changed or not:
ifdef CONFIG_NAND_SPL CONFIG_SYS_TEXT_BASE = 0x87ec0000 else CONFIG_SYS_TEXT_BASE = 0x87f00000 endif
I think they are ok - both addresses are valid RAM addresses. The relocation will move then the code at the end of the RAM. And as I understood from i.MX31 manual, the NFC controller does not use the IRAM at all, so the area pointed by your starting stack pointer should not be overwritten.
If anyone has any comments/suggestions I will appreciate it.
No great idea, really. Probably you need to attach a JTAG debugger and see what happens.
Yes, I am setting up a OpenOCD JTAG here to debug this.
Thanks,
Fabio Estevam

Hi all
On 01/14/2011 07:33 PM, Fabio Estevam wrote:
Hi Stefano,
On 1/13/2011 11:38 AM, Stefano Babic wrote:
On 01/12/2011 01:49 PM, Fabio Estevam wrote:
Hi,
Hi Fabio,
I am trying to make the new relocation scheme to work on the mx31pdk board.
With this patch applied the mx31pdk build works, but not able to get a U-boot prompt yet.
I have tried to imagine some issues, but I cannot find a clear reason. Building with your patch I checked that nand_spl is still less than 2KB code, and that matches the NAND page, as required by i.MX31 - so it is not a problem.
Have you tried to disable the relocation, just to check if the relocation is an issue with CONFIG_SKIP_RELOCATE_UBOOT ? This is not a solution, but only to check what happens.
I've done some testing now and ended up comparing start.S for ARM1136 with ARM926EJS since the latter is used on the Karo TX25 board which seems to have been updated and also boots from NAND.
The result is that applying the following patch on top of Fabios patch makes the i.MX31 PDK boot from NAND. Booting Linux from TFTP works nicely. However the first few lines of output from U-boot is missing, only the "NAND: 256 MB" line is shown. I haven't tried to understand how booting works nowadays and why these changes work, perhaps someone with more insight in the mechanisms can figure out the correct assembler code.
I have no idea if this breaks other boards but at least it's start for further work. I tried it on the imx31 litekit (which boots from NOR) but that board doesn't seem to boot even before applying Fabios patch, I'll see if I can figure out why that board is broken now. Don't know when though.
Regards, Magnus Lilja
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 12545c2..7d75ecf 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -163,6 +163,9 @@ call_board_init_f: bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ ldr r0,=0x00000000
+#if 1 + bl board_init_f +#else #ifdef CONFIG_NAND_SPL bl nand_boot #else @@ -172,6 +175,7 @@ call_board_init_f: bl board_init_f #endif /* CONFIG_ONENAND_IPL */ #endif /* CONFIG_NAND_SPL */ +#endif
/*------------------------------------------------------------------------------*/
@@ -266,11 +270,19 @@ clbss_l:str r2, [r0] /* clear loop... */ * initialization, now running from RAM. */ #ifdef CONFIG_NAND_SPL +#if 1 + ldr r0, _nand_boot_ofs + mov pc, r0 + +_nand_boot_ofs: + .word nand_boot +#else ldr r0, _nand_boot_ofs adr r1, _start add pc, r0, r1 _nand_boot_ofs: .word nand_boot - _start +#endif #else jump_2_ram: ldr r0, _board_init_r_ofs

Le 06/02/2011 13:03, Magnus Lilja a écrit :
Hi all
On 01/14/2011 07:33 PM, Fabio Estevam wrote:
Hi Stefano,
On 1/13/2011 11:38 AM, Stefano Babic wrote:
On 01/12/2011 01:49 PM, Fabio Estevam wrote:
Hi,
Hi Fabio,
I am trying to make the new relocation scheme to work on the mx31pdk board.
With this patch applied the mx31pdk build works, but not able to get a U-boot prompt yet.
I have tried to imagine some issues, but I cannot find a clear reason. Building with your patch I checked that nand_spl is still less than 2KB code, and that matches the NAND page, as required by i.MX31 - so it is not a problem.
Have you tried to disable the relocation, just to check if the relocation is an issue with CONFIG_SKIP_RELOCATE_UBOOT ? This is not a solution, but only to check what happens.
I've done some testing now and ended up comparing start.S for ARM1136 with ARM926EJS since the latter is used on the Karo TX25 board which seems to have been updated and also boots from NAND.
The result is that applying the following patch on top of Fabios patch makes the i.MX31 PDK boot from NAND. Booting Linux from TFTP works nicely. However the first few lines of output from U-boot is missing, only the "NAND: 256 MB" line is shown. I haven't tried to understand how booting works nowadays and why these changes work, perhaps someone with more insight in the mechanisms can figure out the correct assembler code.
I have no idea if this breaks other boards but at least it's start for further work. I tried it on the imx31 litekit (which boots from NOR) but that board doesn't seem to boot even before applying Fabios patch, I'll see if I can figure out why that board is broken now. Don't know when though.
Regards, Magnus Lilja
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 12545c2..7d75ecf 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -163,6 +163,9 @@ call_board_init_f: bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ ldr r0,=0x00000000
+#if 1
bl board_init_f
+#else #ifdef CONFIG_NAND_SPL bl nand_boot #else @@ -172,6 +175,7 @@ call_board_init_f: bl board_init_f #endif /* CONFIG_ONENAND_IPL */ #endif /* CONFIG_NAND_SPL */ +#endif
/*------------------------------------------------------------------------------*/
@@ -266,11 +270,19 @@ clbss_l:str r2, [r0] /* clear loop... */
- initialization, now running from RAM.
*/ #ifdef CONFIG_NAND_SPL +#if 1
ldr r0, _nand_boot_ofs
mov pc, r0
+_nand_boot_ofs:
.word nand_boot
+#else ldr r0, _nand_boot_ofs adr r1, _start add pc, r0, r1 _nand_boot_ofs: .word nand_boot - _start +#endif #else jump_2_ram: ldr r0, _board_init_r_ofs _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Can you repost the diff without those pesky '#if 1...#else...#endif' additions? Just take the current master code, do the changes needed to make it work without trying to keep the old lines around, then do the diff. I'll be easier for all to see the changes.
Amicalement,

Hi Magnus,
On 2/6/2011 10:03 AM, Magnus Lilja wrote: ...
I've done some testing now and ended up comparing start.S for ARM1136 with ARM926EJS since the latter is used on the Karo TX25 board which seems to have been updated and also boots from NAND.
Thanks for looking into this.
The result is that applying the following patch on top of Fabios patch makes the i.MX31 PDK boot from NAND. Booting Linux from TFTP works nicely. However the first few lines of output from U-boot is missing, only the "NAND: 256 MB" line is shown. I haven't tried to understand how booting works nowadays and why these changes work, perhaps someone with more insight in the mechanisms can figure out the correct assembler code.
I think that the missing lines can be fixed by using a similar approach as to this patch: http://git.denx.de/?p=u-boot.git;a=commitdiff;h=877eb0f91543dc5bca385bb6d224...
I have no idea if this breaks other boards but at least it's start for further work. I tried it on the imx31 litekit (which boots from NOR) but that board doesn't seem to boot even before applying Fabios patch, I'll see if I can figure out why that board is broken now. Don't know when though.
I will let others comment about the changes you did in arch/arm/cpu/arm1136/start.S Will also try it later today.
Thanks,
Fabio Estevam
Regards, Magnus Lilja
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 12545c2..7d75ecf 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -163,6 +163,9 @@ call_board_init_f: bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ ldr r0,=0x00000000
+#if 1
bl board_init_f
+#else #ifdef CONFIG_NAND_SPL bl nand_boot #else @@ -172,6 +175,7 @@ call_board_init_f: bl board_init_f #endif /* CONFIG_ONENAND_IPL */ #endif /* CONFIG_NAND_SPL */ +#endif
/*------------------------------------------------------------------------------*/
@@ -266,11 +270,19 @@ clbss_l:str r2, [r0] /* clear loop... */
- initialization, now running from RAM.
*/ #ifdef CONFIG_NAND_SPL +#if 1
ldr r0, _nand_boot_ofs
mov pc, r0
+_nand_boot_ofs:
.word nand_boot
+#else ldr r0, _nand_boot_ofs adr r1, _start add pc, r0, r1 _nand_boot_ofs: .word nand_boot - _start +#endif #else jump_2_ram: ldr r0, _board_init_r_ofs

On 02/07/2011 12:32 PM, Fabio Estevam wrote:
Hi Magnus,
On 2/6/2011 10:03 AM, Magnus Lilja wrote: ...
Hi,
I have no idea if this breaks other boards but at least it's start for further work. I tried it on the imx31 litekit (which boots from NOR) but that board doesn't seem to boot even before applying Fabios patch, I'll see if I can figure out why that board is broken now. Don't know when though.
I will let others comment about the changes you did in arch/arm/cpu/arm1136/start.S Will also try it later today.
Anyway, arch/arm/cpu/arm1136/start.S cannot be compiled without the changes suggested by Magnus due to the following lines:
_nand_boot_ofs : .word nand_boot - _start
":" seems to me wrong in any case and should be fixed. Is this syntax accepted by newer compiler releases ?
IMHO board_init_f must be called absolutely before nand_boot. I have tested the changes suggested by Magnus on a i.MX35 and the board boots from NAND. However, I do not see the problems with the console, and I can think they are not related to this issue.
Best regards, Stefano Babic

Hi
On 2011-02-07 15:13, Stefano Babic wrote:
I have no idea if this breaks other boards but at least it's start for further work. I tried it on the imx31 litekit (which boots from NOR) but that board doesn't seem to boot even before applying Fabios patch, I'll see if I can figure out why that board is broken now. Don't know when though.
I will let others comment about the changes you did in arch/arm/cpu/arm1136/start.S Will also try it later today.
Anyway, arch/arm/cpu/arm1136/start.S cannot be compiled without the changes suggested by Magnus due to the following lines:
_nand_boot_ofs : .word nand_boot - _start
":" seems to me wrong in any case and should be fixed. Is this syntax accepted by newer compiler releases ?
IMHO board_init_f must be called absolutely before nand_boot. I have tested the changes suggested by Magnus on a i.MX35 and the board boots from NAND. However, I do not see the problems with the console, and I can think they are not related to this issue. >
I agree on that last statement, the console thing must be something else.
Here's a somewhat cleaner version of my patch. Hope the mail looks ok, I'm having internet connectivity issues this evening so I'm using a different installation of Thunderbird than usual.
Regards, Magnus
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 12545c2..bab2868 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -163,15 +163,7 @@ call_board_init_f: bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ ldr r0,=0x00000000
-#ifdef CONFIG_NAND_SPL - bl nand_boot -#else -#ifdef CONFIG_ONENAND_IPL - bl start_oneboot -#else bl board_init_f -#endif /* CONFIG_ONENAND_IPL */ -#endif /* CONFIG_NAND_SPL */
/*------------------------------------------------------------------------------*/
@@ -267,10 +259,10 @@ clbss_l:str r2, [r0] /* clear loop... */ */ #ifdef CONFIG_NAND_SPL ldr r0, _nand_boot_ofs - adr r1, _start - add pc, r0, r1 -_nand_boot_ofs: - .word nand_boot - _start + mov pc, r0 + +_nand_boot_ofs: + .word nand_boot #else jump_2_ram: ldr r0, _board_init_r_ofs

Hi Stefano,
On 2/7/2011 5:48 PM, Magnus Lilja wrote: ...
Here's a somewhat cleaner version of my patch. Hope the mail looks ok, I'm having internet connectivity issues this evening so I'm using a different installation of Thunderbird than usual.
Regards, Magnus
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 12545c2..bab2868 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -163,15 +163,7 @@ call_board_init_f: bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ ldr r0,=0x00000000
-#ifdef CONFIG_NAND_SPL
bl nand_boot
-#else -#ifdef CONFIG_ONENAND_IPL
bl start_oneboot
-#else bl board_init_f -#endif /* CONFIG_ONENAND_IPL */ -#endif /* CONFIG_NAND_SPL */
/*------------------------------------------------------------------------------*/
@@ -267,10 +259,10 @@ clbss_l:str r2, [r0] /* clear loop... */ */ #ifdef CONFIG_NAND_SPL ldr r0, _nand_boot_ofs
adr r1, _start
add pc, r0, r1
-_nand_boot_ofs:
.word nand_boot - _start
mov pc, r0
+_nand_boot_ofs:
.word nand_boot
#else jump_2_ram: ldr r0, _board_init_r_ofs
I confirmed that by applying my original patch of this thread plus Magnus´ patch above I can get MX31PDK to boot.
Please let me know how you want me to proceed.
Thanks,
Fabio Estevam

Am 08.02.2011 18:09, schrieb Fabio Estevam:
I confirmed that by applying my original patch of this thread plus Magnus´ patch above I can get MX31PDK to boot.
Fine.
Please let me know how you want me to proceed.
I think the correct way is that Magnus adds his Signed-off-by to his patch, repushing the patch to the list. Please put Albert in CC, as this file is competence of the ARM maintainer (well, we tested only on i.MX, I see...). I will take your patch for the mx31pdk and I will merge it on u-boot-imx (and including it in the next pull request as well).
Stefano

Hi
Please let me know how you want me to proceed.
I think the correct way is that Magnus adds his Signed-off-by to his patch, repushing the patch to the list. Please put Albert in CC, as this file is competence of the ARM maintainer (well, we tested only on i.MX, I see...). I will take your patch for the mx31pdk and I will merge it on u-boot-imx (and including it in the next pull request as well).
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first. Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files. I cannot work on that before Thursday or Friday though.
Regards, Magnus Lilja

Am 08.02.2011 20:26, schrieb Magnus Lilja:
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first.
I think your patch is ok - Fabio fixed the syntax error as you do. We need only one of them.
Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files.
IMHO this is the preferred way, because the two issues are orthogonal. Your patch fixes booting from NAND for ARM11, and Fabio's patch fix the mx31pdk board only.
Regards, Stefano

Le 08/02/2011 21:18, stefano babic a écrit :
Am 08.02.2011 20:26, schrieb Magnus Lilja:
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first.
I think your patch is ok - Fabio fixed the syntax error as you do. We need only one of them.
Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files.
IMHO this is the preferred way, because the two issues are orthogonal. Your patch fixes booting from NAND for ARM11, and Fabio's patch fix the mx31pdk board only.
Agreed.
Note also that there was a recent patch to ARM926's start.S (replacing 'adr r1, _start' with 'ldr r1, _TEXT_BASE' at line 284). The same should be done on arm1136.
Regards, Stefano
Amicalement,

Hi Albert,
On 2/8/2011 6:50 PM, Albert ARIBAUD wrote:
Le 08/02/2011 21:18, stefano babic a écrit :
Am 08.02.2011 20:26, schrieb Magnus Lilja:
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first.
I think your patch is ok - Fabio fixed the syntax error as you do. We need only one of them.
Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files.
IMHO this is the preferred way, because the two issues are orthogonal. Your patch fixes booting from NAND for ARM11, and Fabio's patch fix the mx31pdk board only.
Agreed.
Ok, I have just submitted the patch series treating one issue at the time.
Note also that there was a recent patch to ARM926's start.S (replacing 'adr r1, _start' with 'ldr r1, _TEXT_BASE' at line 284). The same should be done on arm1136.
Ok, I haven´t added this change to my patch series yet, but I can do it on a separate patch after my original patch series is applied, if this is OK with you.
I have tested this recommended change and it worked fine on my mx31pdk board.
Thanks,
Fabio Estevam

Hi Albert,
On Wednesday 09 February 2011 02:20 AM, Albert ARIBAUD wrote:
Le 08/02/2011 21:18, stefano babic a écrit :
Am 08.02.2011 20:26, schrieb Magnus Lilja:
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first.
I think your patch is ok - Fabio fixed the syntax error as you do. We need only one of them.
Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files.
IMHO this is the preferred way, because the two issues are orthogonal. Your patch fixes booting from NAND for ARM11, and Fabio's patch fix the mx31pdk board only.
Agreed.
Note also that there was a recent patch to ARM926's start.S (replacing 'adr r1, _start' with 'ldr r1, _TEXT_BASE' at line 284). The same should be done on arm1136.
Is this going to happen for armv7 too? What is the real reason behind this proposal. What is the case when _start is not same as _TEXT_BASE(I looked at the archives but couldn't filter out the original discussion on this)
I see a problem with that. _TEXT_BASE is based on CONFIG_SYS_TEXT_BASE. In our SPL's case CONFIG_SYS_TEXT_BASE indicates the TEXT_BASE for u-boot and *CONFIG_SYS_SPL_TEXT_BASE* indicates the TEXT_BASE for SPL. Both are defined and useful in SPL because one is used for linking SPL while the other is used while loading u-boot from MMC. So, CONFIG_SYS_TEXT_BASE used in the start.S of SPL will not be correct.
In the worst case we need to define yet another label in the linker scripts like __text_base. But I was wondering if we could maintain the status quo for armv7: that is 'adr r1, _start'
Best regards, Aneesh

Le 11/02/2011 11:51, Aneesh V a écrit :
Hi Albert,
On Wednesday 09 February 2011 02:20 AM, Albert ARIBAUD wrote:
Le 08/02/2011 21:18, stefano babic a écrit :
Am 08.02.2011 20:26, schrieb Magnus Lilja:
Patch reposted as a separate mail a couple of minutes ago.
As I mention in the patch I think Fabio's patch has to be applied first.
I think your patch is ok - Fabio fixed the syntax error as you do. We need only one of them.
Another solution would be to change my patch somewhat to apply it first and then update Fabios patch to only touch the i.MX31-PDK specific files.
IMHO this is the preferred way, because the two issues are orthogonal. Your patch fixes booting from NAND for ARM11, and Fabio's patch fix the mx31pdk board only.
Agreed.
Note also that there was a recent patch to ARM926's start.S (replacing 'adr r1, _start' with 'ldr r1, _TEXT_BASE' at line 284). The same should be done on arm1136.
Is this going to happen for armv7 too? What is the real reason behind this proposal. What is the case when _start is not same as _TEXT_BASE(I looked at the archives but couldn't filter out the original discussion on this)
The difference is that _TEXT_BASE always contains the link-time address of _start, whereas references to _start may contain a different value if the code is executed somewhere else than at the link-time address.
/Normally/, u-boot should always execute first at the link-time address -- that's a base constraint.
/But/ this change makes it more resilient to out-of-link-time-address execution, and I want, at some time in the future, to find a way for u-boot to be able to start anywhere -- within reasonable limits: anywhere in NOR for a NOR-based U-boot, anywhere in RAM for a RAM-based U-boot, but I am not talking about a generic, run-in-RAM-or-NOR-or-anywhere, binary.
Yet. :)
I see a problem with that. _TEXT_BASE is based on CONFIG_SYS_TEXT_BASE. In our SPL's case CONFIG_SYS_TEXT_BASE indicates the TEXT_BASE for u-boot and *CONFIG_SYS_SPL_TEXT_BASE* indicates the TEXT_BASE for SPL. Both are defined and useful in SPL because one is used for linking SPL while the other is used while loading u-boot from MMC. So, CONFIG_SYS_TEXT_BASE used in the start.S of SPL will not be correct.
The change I indicate is under the #else of a #ifdef CONFIG_NAND_SPL, so it will not apply to SPL. Does that still cause an issue with armv7?
In the worst case we need to define yet another label in the linker scripts like __text_base. But I was wondering if we could maintain the status quo for armv7: that is 'adr r1, _start'
As long as you run the u-boot start code at the link-time address, there will be no difference except the code is more correct with respect to what it should do; and if you run it elsewhere, which you should not, you have slightly better chances that it manages to survive.
Best regards, Aneesh
Amicalement,

On Friday 11 February 2011 06:16 PM, Albert ARIBAUD wrote: [snip...]
Note also that there was a recent patch to ARM926's start.S (replacing 'adr r1, _start' with 'ldr r1, _TEXT_BASE' at line 284). The same should be done on arm1136.
Is this going to happen for armv7 too? What is the real reason behind this proposal. What is the case when _start is not same as _TEXT_BASE(I looked at the archives but couldn't filter out the original discussion on this)
The difference is that _TEXT_BASE always contains the link-time address of _start, whereas references to _start may contain a different value if the code is executed somewhere else than at the link-time address.
/Normally/, u-boot should always execute first at the link-time address -- that's a base constraint.
/But/ this change makes it more resilient to out-of-link-time-address execution, and I want, at some time in the future, to find a way for u-boot to be able to start anywhere -- within reasonable limits: anywhere in NOR for a NOR-based U-boot, anywhere in RAM for a RAM-based U-boot, but I am not talking about a generic, run-in-RAM-or-NOR-or-anywhere, binary.
Yet. :)
I see a problem with that. _TEXT_BASE is based on CONFIG_SYS_TEXT_BASE. In our SPL's case CONFIG_SYS_TEXT_BASE indicates the TEXT_BASE for u-boot and *CONFIG_SYS_SPL_TEXT_BASE* indicates the TEXT_BASE for SPL. Both are defined and useful in SPL because one is used for linking SPL while the other is used while loading u-boot from MMC. So, CONFIG_SYS_TEXT_BASE used in the start.S of SPL will not be correct.
The change I indicate is under the #else of a #ifdef CONFIG_NAND_SPL, so it will not apply to SPL. Does that still cause an issue with armv7?
No. It doesn't. I am fine with this change if it applies only to u-boot.
br, Aneesh
participants (6)
-
Albert ARIBAUD
-
Aneesh V
-
Fabio Estevam
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Magnus Lilja
-
Stefano Babic
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stefano babic