AM437x evm - boot from ethernet

Roger McCalman51

Other Parts Discussed in Thread: AM1808, OMAP-L138

I have am AM437x EVM and want to try out booting from the ethernet port. That is I wish to load the u-boot SPL, u-boot and Linux via ethernet.

I have set the SW11 and SW12 to what I think are the correct values (sysboot 0-4 = 11100b for emac1 and sysboot5=1 for RGMII)

I have the RJ45 (J18) connected directly to my laptop and on power up or reset I see no network traffic.

I assume that when SW11 and SW12 switches are 'on' it selects 0 on the sysboot pin

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi Roger,

Please see Advisory 4 in the AM437X Errata.

0 Roger McCalman51 over 9 years ago in reply to Biser Gatchev-XID

Intellectual 335 points

The errata Advisory 10 "ROM: Peripheral Boot is Not Supported" implies that booting from the UART is also not supported. This was my backup plan. Also Advisory 15 "ROM: NAND Boot Mode is Unsupported" also implies that we can't boot from NAND either. Is this true? The EVM I have has part XAM437XAZDN

0 Biser Gatchev-XID over 9 years ago in reply to Roger McCalman51

TI__Guru**** 393215 points

Unfortunately this device is silicon revision 1.1, so all these errata apply.

0 Roger McCalman51 over 9 years ago in reply to Biser Gatchev-XID

Intellectual 335 points

Thanks for the feedback. What is the failure mode of the UART boot? I can see the 'C' for the x-modem download and minicom/kermit both complete the download of the u-boot-spl.bin but I see nothing happening after that.

0 Biser Gatchev-XID over 9 years ago in reply to Roger McCalman51

TI__Guru**** 393215 points

I have heard of minicom issues with AM335X too. Can you try with picocom?

0 Roger McCalman51 over 9 years ago in reply to Biser Gatchev-XID

Intellectual 335 points

I managed to get the SPL to load and execute after setting the correct value of CONFIG_SPL_TEXT_BASE to the value in the datasheet.

I changed the spl to not use the boot_device that it was booted from but to use the ethernet to load u-boot. This worked and u-boot starts and runs.

When I load the kernel that I have built it fails to get past "Starting kernel...". When the same kernel is loaded via the MMC supplied SPL/U-boot it works.

My patch for the evm config is below

Index: include/configs/am43xx_evm.h
===================================================================
--- include/configs/am43xx_evm.h        (revision 13468)
+++ include/configs/am43xx_evm.h        (working copy)
@@ -9,6 +9,8 @@
 #ifndef __CONFIG_AM43XX_EVM_H
 #define __CONFIG_AM43XX_EVM_H
 
+#define CONFIG_TFTP_BLOCKSIZE 1024
+
 #define CONFIG_AM43XX
 
 #define CONFIG_BOARD_LATE_INIT
@@ -33,7 +35,7 @@
 #define CONFIG_SYS_I2C_MULTI_EEPROMS
 
 /* SPL defines. */
-#define CONFIG_SPL_TEXT_BASE           0x40300350
+#define CONFIG_SPL_TEXT_BASE           0x402F0400
 #define CONFIG_SPL_MAX_SIZE            (220 <

0 Biser Gatchev-XID over 9 years ago in reply to Roger McCalman51

TI__Guru**** 393215 points

Good to hear! I'm not a SW expert, but maybe it's again the load address for the kernel?

0 Roger McCalman51 over 9 years ago in reply to Biser Gatchev-XID

Intellectual 335 points

I checked all the addresses of the kernel and the fdt and they match with the u-boot that works.

0 Biser Gatchev-XID over 9 years ago in reply to Roger McCalman51

TI__Guru**** 393215 points

Afraid I cannot help on this.

0 Roger McCalman51 over 9 years ago in reply to Biser Gatchev-XID

Intellectual 335 points

Is there any more information on the errata Advisory 10 which says

Advisory 10 ROM: Peripheral Boot is Not Supported
Revisions Affected 1.1
Details Boot modes affected: USB_CL, UART, EMAC
Peripheral boot modes USB_CL, UART, and EMAC are not supported on affected
devices

I am not sure this is accurate as I have booted via the UART and run the SPL and U-boot. What is the failure and what does not work?

0 Biser Gatchev-XID over 9 years ago in reply to Roger McCalman51

TI__Guru**** 393215 points

There are no further details than that. These are ROM code issues and ROM code information is not available publicly beyond what's published in the TRM.

0 Steve Kipisz over 9 years ago in reply to Biser Gatchev-XID

TI__Genius 15510 points

The issue should be fixed in PG 1.2. The boot ROM expects the image to be built to load at address 0x402F0400, but there is an issue where you can load the SPL there and then load u-boot and they work. Booting a kernel will fail.

Steve K.

0 Roger McCalman51 over 9 years ago in reply to Steve Kipisz

Intellectual 335 points

That's what I found. I find it hard to understand how the boot ROM can effect the loading of the kernel after running the SPL and U-boot, but it is certainly what I have found.

We are building our own boards and are hoping to get PG1.2 parts but I was trying to use the EVM to started porting code from AM1808 to the AM437x, in particular the factory initialisation.

On the EVM will using SPL/U-Boot to write MLO/u-boot to the NAND work?

My plan is to use the UART loading to boot a kernel from the network which will then create a ubifs filesystem and put the kernel in it and update u-boot to use that kernel rather than an image in a NAND partition. Some of the errata for PG1.1 seem to imply that booting from NAND does not work.

0 JJD over 9 years ago in reply to Roger McCalman51

TI__Guru 68880 points

Hi Roger, unfortunately, NAND boot will not work properly on PG1.1 devices. There are several problems, the main one of which is that the ROM incorrectly checks for valid blocks during boot, and renders an otherwise good NAND as bad and skips to the next booting device.

Is there any way you can stick with SD card instead of the NAND during your development?

Regards,

James

0 Roger McCalman51 over 9 years ago in reply to JJD

Intellectual 335 points

Using the EVM that should be possible - I only need to put the MLO on the MMC and then it can load u-boot from NAND which can then load the kernel/ftb from the UBIFS as you say that its is the ROM that has the problem..

I am still pondering why I can't load a kernel from a u-boot that has been loaded by a UART loaded SPL - if it is not a address conflict of the loaded programs then the ROM must be doing something horrible to the processor...

Anyway thanks for the help.

0 vefone over 8 years ago

Expert 2440 points

Hi,
Roger McCalman51, I face the same problem like you,do you solve the problem?

Best Regards
Vefone

0 Roger McCalman51 over 8 years ago in reply to vefone

Intellectual 335 points

No. I we gave up trying to use this processor as apart from the booting issue the pin grid pitch was causing issues on our board layout. We actually are using an OMAP-L138 (Am1808 + DSP) in the short term as that required no PCB changes and are looking at the next generation processors.

0 sivak over 8 years ago in reply to Roger McCalman51

TI__Genius 9535 points

Roger,

Could you help with more specific details on the board layout issues with the pin grid pitch? We do have layout examples that highlight escape routing if that is the area of concern.

Regards, Siva

0 Roger McCalman51 over 8 years ago in reply to sivak

Intellectual 335 points

I am not a PCB person but I think it would was likely cause issues with the rest of the board area - it is/was a 12 or 14 layer board with many analog devices on and the vias (possibly blind ones) were likely to cause issues when drilling

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AM437x evm - boot from ethernet