CCS/AM3358: Unable to run USB0 code from internal RAM

Hi Harish,

Because the AM335x ROM bootloader does not support USB boot (SD/MMC, UART, NAND, and QSPI only), so you will have to implement your own boot from USB. The best way to accomplish what you need is to add the USB Bulk function into the SBL (Secondary Bootloader).

SBL source code is at  C:\ti_am3_610\pdk_am335x_1_0_16\packages\ti\starterware\bootloader

USB Bulk example is at C:\ti_am3_610\pdk_am335x_1_0_16\packages\ti\drv\usb\example\usb_dev\bulk

You have to combine those two into one.

Ming

Hi Ming,

ThanksTfor your reply,

Actually I am creating itself Secondary Booltloader and for that using TI Starterware v2.0.1.1.

As per your suggestion we have allready merged Starterware bootloader and usb bulk example into the Secondary Bootloader. First I have checked USB bulk example in Application code(On DDR) USB is running well then USB code merged with Secondary Bootloader code but code is stuck with USBBulkInit inside Secondary bootloader.

So Is any extra Intialization is required ?

And Is USB stack memory configuration need to change ?

Regards,

Harish

Hi Harish,

SBL and USB Bulk are two application programs. If you want to combine them into one, you will need adjust the link command file for the SBL to accommodate both applications.

The other way to do it is to convert the USB Bulk application (adding your new features) into app and leave the SBL intact, so the RBL (ROM Bootloader) --> SBL --> app. This way you can focus on your new app without worrying the combine SBL and USB Bulk.

Ming  

Hi Ming,

We have allready  following RBL-----> SBL ------> App this way, Here we are boot from NAND Flash and in application code USB Bulk is used. This flow is working properly but as per our requirement USB bulk part should be add into the SBL.

So we have add the USB bulk part into the SBL but it's stuck with USBBulkinit.

As per our observation USBBulkInit is stuck due to the interrupt issue. For testing I have add timer overflow interrupt into the SBL code after Interrupt generated processor is not jump to timer ISR its stuck with somewhere. I thought this happen due to the Interrupt vector table is not assigned properly.

So please suggest me how to configure Interrupt vector table properly.

Hi Harish,

See my answer in https://e2e.ti.com/support/processors/f/791/t/874356

Ming

Hi Ming,

In our case, we are not using RTOS SDK for development of SBL as well as application.

We are using non RTOS AM335X_StarterWare_02_00_01_01 for development of SBL and application using CCS(Code composer Studio version 8.3.)

In application code development, for IVT(Interrupt vector table) initialization

C:\Harish\Development tool\AM335X_StarterWare_02_00_01_01\system_config\armv7a\am335x\startup.c file is used.

But in case of SBL, C:\ti\AM335X_StarterWare_02_00_01_01\bootloader\src\armv7a\cgt\bl_init.asm is used in which we are not able to locate IVT(Interrupt vector table) initialization file.

bl_init.asm is provide below.

;******************************************************************************
;
; init.asm - Init code routines
;
;******************************************************************************
;******************************************************************************
;
;****************************** Global Symbols*******************************
.global Entry
.global start_boot
.global __TI_auto_init

.ref __stack
.ref bss_start
.ref bss_end
.ref start_boot
.ref main

;************************ Internal Definitions ******************************
;
; Define the stack sizes for different modes. The user/system mode will use
; the rest of the total stack size
;

UND_STACK_SIZE .set 0x8
ABT_STACK_SIZE .set 0x8
FIQ_STACK_SIZE .set 0x8
IRQ_STACK_SIZE .set 0x100
SVC_STACK_SIZE .set 0x8

;
; to set the mode bits in CPSR for different modes
;

MODE_USR .set 0x10
MODE_FIQ .set 0x11
MODE_IRQ .set 0x12
MODE_SVC .set 0x13
MODE_ABT .set 0x17
MODE_UND .set 0x1B
MODE_SYS .set 0x1F

I_F_BIT .set 0xC0

;**************************** Code Seection ***********************************
.text

;
; This code is assembled for ARM instructions
;
.state32

;******************************************************************************
;
;******************************************************************************
;
; The reset handler sets up the stack pointers for all the modes. The FIQ and
; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the
; main() function.
;
Entry:
;
; Set up the Stack for Undefined mode
;
LDR r0, _stackptr ; Read the stack address
MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode
MOV sp,r0 ; write the stack pointer
SUB r0, r0, #UND_STACK_SIZE ; give stack space
;
; Set up the Stack for abort mode
;
MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode
MOV sp, r0 ; write the stack pointer
SUB r0,r0, #ABT_STACK_SIZE ; give stack space
;
; Set up the Stack for FIQ mode
;
MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode
MOV sp,r0 ; write the stack pointer
SUB r0,r0, #FIQ_STACK_SIZE ; give stack space
;
; Set up the Stack for IRQ mode
;
MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode
MOV sp,r0 ; write the stack pointer
SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
;
; Set up the Stack for SVC mode
;
MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
MOV sp,r0 ; write the stack pointer
SUB r0,r0, #SVC_STACK_SIZE ; give stack space
;
; Set up the Stack for USer/System mode
;
MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode
MOV sp,r0 ; write the stack pointer
;
; Clear the BSS section here
;
Clear_Bss_Section:

LDR r0, _bss_start ; Start address of BSS
LDR r1, _bss_end ; End address of BSS
SUB r1,r1,#4
MOV r2, #0
Loop:
STR r2, [r0], #4 ; Clear one word in BSS
CMP r0, r1
BLE Loop ; Clear till BSS end

;
; Enter the start_boot function. The execution still happens in system mode
;
LDR r10, _main ; Get the address of main
MOV lr,pc ; Dummy return to main
BX r10 ; Branch to main
SUB pc, pc, #0x08 ; looping

; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
; BX lr
;
; End of the file
;

_stackptr:
.word __stack
_bss_start:
.word bss_start
_bss_end:
.word bss_end
_main:
.word main
_data_auto_init:
.word __TI_auto_init
.end

Is this initialization is sufficient for writing IVT(Interrupt vector table) that is required in case of interrupt functionality in SBL code.

Regards,

Harish