Hello,

I have a problem with the flash programming on the AT91SAM7X.
because I think there goes something wrong with the assembler.

I use the Yagarto Toolchain, with Gcc and Eclipse.

I Debug the following function:

RAMFUNC int AT91F_Flash_Unlock(unsigned int Flash_Lock_Page)
{
AT91F_NVM_Init();

//* Protect
AT91F_disable_interrupt();
//* Write the Clear Lock Bit command
AT91C_BASE_MC->MC_FCR = AT91C_MC_CORRECT_KEY | AT91C_MC_FCMD_UNLOCK | (AT91C_MC_PAGEN & (Flash_Lock_Page << 8) ) ;

//* Wait the end of command
AT91F_Flash_Ready();
//* Protect
AT91F_enable_interrupt();

return (AT91F_Flash_Lock_Status());
}

and the gcc makes the following code:

{
0x00200094 <AT91F_Flash_Unlock>: push {r7, lr}
0x00200096 <AT91F_Flash_Unlock+2>: sub sp, #8
0x00200098 <AT91F_Flash_Unlock+4>: add r7, sp, #0
0x0020009a <AT91F_Flash_Unlock+6>: str r0, [r7, #4]
AT91F_NVM_Init();
0x0020009c <AT91F_Flash_Unlock+8>: bl 0x1012ec <AT91F_NVM_Init>

//* Protect
AT91F_disable_interrupt();
0x002000a0 <AT91F_Flash_Unlock+12>: bl 0x200490
//* Write the Clear Lock Bit command
AT91C_BASE_MC->MC_FCR = AT91C_MC_CORRECT_KEY | AT91C_MC_FCMD_UNLOCK | (AT91C_MC_PAGEN & (Flash_Lock_Page << 8) ) ;
0x002000a4 <AT91F_Flash_Unlock+16>: ldr r3, [pc, #40] ; (0x2000d0 <AT91F_Flash_Unlock+60>)
0x002000a6 <AT91F_Flash_Unlock+18>: ldr r2, [r7, #4]
0x002000a8 <AT91F_Flash_Unlock+20>: lsls r1, r2, #8
0x002000aa <AT91F_Flash_Unlock+22>: ldr r2, [pc, #40] ; (0x2000d4 <AT91F_Flash_Unlock+64>)
0x002000ac <AT91F_Flash_Unlock+24>: ands r2, r1
0x002000ae <AT91F_Flash_Unlock+26>: ldr r1, [pc, #40] ; (0x2000d8 <AT91F_Flash_Unlock+68>)
0x002000b0 <AT91F_Flash_Unlock+28>: orrs r2, r1
0x002000b2 <AT91F_Flash_Unlock+30>: str r2, [r3, #100] ; 0x64

//* Wait the end of command
AT91F_Flash_Ready();
0x002000b4 <AT91F_Flash_Unlock+32>: bl 0x200000 <AT91F_Flash_Ready>
//* Protect
AT91F_enable_interrupt();
0x002000b8 <AT91F_Flash_Unlock+36>: bl 0x200498

return (AT91F_Flash_Lock_Status());
0x002000bc <AT91F_Flash_Unlock+40>: bl 0x20002c <AT91F_Flash_Lock_Status>
0x002000c0 <AT91F_Flash_Unlock+44>: movs r0, r0
}
0x002000c2 <AT91F_Flash_Unlock+46>: movs r0, r0
0x002000c4 <AT91F_Flash_Unlock+48>: movs r0, r0
0x002000c6 <AT91F_Flash_Unlock+50>: movs r0, r0
0x002000c8 <AT91F_Flash_Unlock+52>: movs r0, r0
0x002000ca <AT91F_Flash_Unlock+54>: movs r0, r0
0x002000cc <AT91F_Flash_Unlock+56>: bx r1
0x002000ce <AT91F_Flash_Unlock+58>: nop ; (mov r8, r8)
0x002000d0 <AT91F_Flash_Unlock+60>: ; <UNDEFINED> instruction: 0xff00ffff
0x002000d4 <AT91F_Flash_Unlock+64>: vhadd.u8 d0, d0, d3
0x002000d8 <AT91F_Flash_Unlock+68>: movs r4, r0
0x002000da <AT91F_Flash_Unlock+70>: ldrh r0, [r0, r0]

I don't understand why there are 6 movs r0, r0. It makes no sense for me.

Has someone a idea what it could be?

I hope there is a person who can help me.