Re: [ECOS] small custom bootloader to start an app stored in flash

[Oleg Uzenkov <o.uzenkov@unicore.co.ua>]

Thanks,
>> Any ideas how to make a jump to start an app? May be some sample code
>> showing how to do it in eCos? May be someone has done it already?
> // Make a function pointer and assigned it to the address you want to jump to.
> void (*startApp1)(void) = 0x08002000 ;
>
> // Disable the interrupts.
> cyg_interrupt_disable();
>
> //Call the function.
> startApp1();
I have tried it but could not get it working yet (stm32f4-discovery board).

May be I am missing something in the understanding of the principles.

Please could you check.

1. Here is the code of my bootloader:

...
static void (*startApp)(void) = ( void(*)(void) ) (0x08020000) ;

int main (void) {

   diag_printf( "IN JUMP\n" );

   cyg_interrupt_disable();

   startApp();

   while (1);

   return 0;
}

I build it with ROM startup and flash at 0x08000000

mlt files:

*.ldi:

MEMORY
{
     ram   : ORIGIN = 0x20000000, LENGTH = 
0x00020000-CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
     flash : ORIGIN = 0x08000000, LENGTH = 0x00100000
     ccm   : ORIGIN = 0x10000000, LENGTH = 0x00010000
}

hal_vsr_table = 0x20000000;
hal_virtual_vector_table = hal_vsr_table + 98*4;
#if defined(CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT)
hal_virtual_vector_table_end = hal_virtual_vector_table + 64*4;
#else // zero size virtual vector table
hal_virtual_vector_table_end = hal_virtual_vector_table;
#endif

// SRAM is 128k.
hal_startup_stack = 0x20000000 + 1024*128;

SECTIONS
{
     SECTIONS_BEGIN
     USER_SECTION (ccm, ccm, 0x10000000 (NOLOAD), LMA_EQ_VMA)
     SECTION_rom_vectors (flash, 0x08000000, LMA_EQ_VMA)
     SECTION_RELOCS (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_text (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_fini (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_rodata (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_rodata1 (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_fixup (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_gcc_except_table (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_eh_frame (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_got (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_sram (ram, hal_virtual_vector_table_end, FOLLOWING (.got))
     SECTION_data (ram, ALIGN( 0x8), FOLLOWING (.sram))
     SECTION_bss (ram, ALIGN (0x8), LMA_EQ_VMA)
     CYG_LABEL_DEFN(__heap1) = ALIGN (0x8);
     SECTIONS_END
}

*.h:
#define CYGMEM_REGION_ram (0x20000000)
#define CYGMEM_REGION_ram_SIZE 
(0x00020000-CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE)
#define CYGMEM_REGION_ram_ATTR (CYGMEM_REGION_ATTR_R | CYGMEM_REGION_ATTR_W)
#define CYGMEM_REGION_ccm (0x10000000)
#define CYGMEM_REGION_ccm_SIZE (0x00010000)
#define CYGMEM_REGION_ccm_ATTR (CYGMEM_REGION_ATTR_R | CYGMEM_REGION_ATTR_W)
#define CYGMEM_REGION_flash (0x08000000)
#define CYGMEM_REGION_flash_SIZE (0x00100000)
#define CYGMEM_REGION_flash_ATTR (CYGMEM_REGION_ATTR_R | 
CYGMEM_REGION_ATTR_W)
#ifndef __ASSEMBLER__
extern char CYG_LABEL_NAME (__heap1) [];
#endif
#define CYGMEM_SECTION_heap1 (CYG_LABEL_NAME (__heap1))
#define CYGMEM_SECTION_heap1_SIZE 
(CYGMEM_REGION_ram+CYGMEM_REGION_ram_SIZE - (size_t) CYG_LABEL_NAME 
(__heap1))

2. Here is the code of my app to which I want to jump to:

int main (void) {

   diag_printf( "IN APP\n" );

   while (1);

   return 0;
}

I build it with ROM startup and flash it at 0x08020000

mlt files:

*.ldi:

MEMORY
{
     ram   : ORIGIN = 0x20000000, LENGTH = 
0x00020000-CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE
     flash : ORIGIN = 0x08020000, LENGTH = 0x00100000 - 0x20000
     ccm   : ORIGIN = 0x10000000, LENGTH = 0x00010000
}

hal_vsr_table = 0x20000000;
hal_virtual_vector_table = hal_vsr_table + 98*4;
#if defined(CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT)
hal_virtual_vector_table_end = hal_virtual_vector_table + 64*4;
#else // zero size virtual vector table
hal_virtual_vector_table_end = hal_virtual_vector_table;
#endif

// SRAM is 128k.
hal_startup_stack = 0x20000000 + 1024*128;

SECTIONS
{
     SECTIONS_BEGIN
     USER_SECTION (ccm, ccm, 0x10000000 (NOLOAD), LMA_EQ_VMA)
     SECTION_rom_vectors (flash, 0x08020000, LMA_EQ_VMA)
     SECTION_RELOCS (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_text (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_fini (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_rodata (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_rodata1 (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_fixup (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_gcc_except_table (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_eh_frame (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_got (flash, ALIGN (0x8), LMA_EQ_VMA)
     SECTION_sram (ram, hal_virtual_vector_table_end, FOLLOWING (.got))
     SECTION_data (ram, ALIGN( 0x8), FOLLOWING (.sram))
     SECTION_bss (ram, ALIGN (0x8), LMA_EQ_VMA)
     CYG_LABEL_DEFN(__heap1) = ALIGN (0x8);
     SECTIONS_END
}

*.h:
#define CYGMEM_REGION_ram (0x20000000)
#define CYGMEM_REGION_ram_SIZE 
(0x00020000-CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE)
#define CYGMEM_REGION_ram_ATTR (CYGMEM_REGION_ATTR_R | CYGMEM_REGION_ATTR_W)
#define CYGMEM_REGION_ccm (0x10000000)
#define CYGMEM_REGION_ccm_SIZE (0x00010000)
#define CYGMEM_REGION_ccm_ATTR (CYGMEM_REGION_ATTR_R | CYGMEM_REGION_ATTR_W)
#define CYGMEM_REGION_flash (0x08020000)
#define CYGMEM_REGION_flash_SIZE (0x00100000 - 0x20000)
#define CYGMEM_REGION_flash_ATTR (CYGMEM_REGION_ATTR_R | 
CYGMEM_REGION_ATTR_W)
#ifndef __ASSEMBLER__
extern char CYG_LABEL_NAME (__heap1) [];
#endif
#define CYGMEM_SECTION_heap1 (CYG_LABEL_NAME (__heap1))
#define CYGMEM_SECTION_heap1_SIZE 
(CYGMEM_REGION_ram+CYGMEM_REGION_ram_SIZE - (size_t) CYG_LABEL_NAME 
(__heap1))

3. I am expecting output to be:
IN JUMP
IN APP

But I do not get to IN APP.

What am I doing wrong?

I tried to jump to 0x08020004 address as it is where hal_reset_vsr is, 
but still no luck.

ROM startup build copies .data and .bss sections into ram, probably 
these sections data gets overwritten.

Do I need to shift addresses of SECTION_sram, SECTION_data, SECTION_bss  
in app's memory layout?

Oleg

P.S:
$ arm-none-eabi-readelf -h app.elf
ELF Header:
   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
   Class:                             ELF32
   Data:                              2's complement, little endian
   Version:                           1 (current)
   OS/ABI:                            UNIX - System V
   ABI Version:                       0
   Type:                              EXEC (Executable file)
   Machine:                           ARM
   Version:                           0x1
   Entry point address:               0x8020111
   Start of program headers:          52 (bytes into file)
   Start of section headers:          24148 (bytes into file)
   Flags:                             0x5000002, has entry point, 
Version5 EABI
   Size of this header:               52 (bytes)
   Size of program headers:           32 (bytes)
   Number of program headers:         3
   Size of section headers:           40 (bytes)
   Number of section headers:         12
   Section header string table index: 11

$ arm-none-eabi-objdump -h app.elf

app.elf:     file format elf32-littlearm

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
   0 .rom_vectors  00000008  08020000  08020000  00000098  2**0
                   CONTENTS, ALLOC, LOAD, READONLY, CODE
   1 .ARM.extab    0000003c  08020008  08020008  000000a0  2**2
                   CONTENTS, ALLOC, LOAD, READONLY, DATA
   2 .ARM.exidx    000000c8  08020048  08020048  000000e0  2**2
                   CONTENTS, ALLOC, LOAD, READONLY, DATA
   3 .text         0000586c  08020110  08020110  000001a8  2**3
                   CONTENTS, ALLOC, LOAD, READONLY, CODE
   4 .rodata       0000010d  08025980  08025980  00005a18  2**2
                   CONTENTS, ALLOC, LOAD, READONLY, DATA
   5 .eh_frame     00000008  08025a90  08025a90  00005b25  2**0
                   ALLOC
   6 .data         00000268  20000288  08025a98  00005b28  2**3
                   CONTENTS, ALLOC, LOAD, DATA
   7 .bss          000034e8  200004f0  08025d00  00005d90  2**3
                   ALLOC
   8 .ARM.attributes 0000002d  00000000  00000000  00005d90  2**0
                   CONTENTS, READONLY
   9 .comment      0000002a  00000000  00000000  00005dbd  2**0
                   CONTENTS, READONLY







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