Baremetal programming with Arrow Cyclone V SoCKit

Hello everyone,

I apologize if this is not the right place to post this. I have a Arrow Cyclone V SoCKit. I am currently trying to do baremetal programming on it, but I am having a lot of trouble with it. I can't do a basic task like turning on/off the backlight of the LCD. Since I am not using Linux, I can't use the "hps_lcd" example code as is so I had to do some modifications. In the example code they use this snippet of code to get the virtual base address:

    // map the address space for the LED registers into user space so we can interact with them.
    // we'll actually map in the entire CSR span of the HPS since we want to access various registers within that span
    if( ( fd = open( "/dev/mem", ( O_RDWR | O_SYNC ) ) ) == -1 ) {
        printf( "ERROR: could not open \"/dev/mem\"...\n" );
        return( 1 );
    }
    virtual_base = mmap( NULL, HW_REGS_SPAN, ( PROT_READ | PROT_WRITE ), MAP_SHARED, fd, HW_REGS_BASE );

They then pass the virtual_base to LCDHW_Init:

# define HW_REGS_BASE ( ALT_STM_OFST )# define HW_REGS_SPAN ( 0x04000000 )# define HW_REGS_MASK ( HW_REGS_SPAN - 1 )
# define HPS_LCM_D_C_BIT_GPIObit62_GPIOreg2            ( 0x00000010 )# define HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1       ( 0x00080000 )  # define HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1    ( 0x00000800 )
    ////////////////////////////////////////////////////
    ////////////////////////////////////////////////////
    ////////////////////////////////////////////////////
    //////// lcd reset
    // set the direction of the HPS GPIO1 bits attached to LCD RESETn to output
    alt_setbits_word( ( virtual_base + ( ( uint32_t )( ALT_GPIO1_SWPORTA_DDR_ADDR ) & ( uint32_t )( HW_REGS_MASK ) ) ), HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
    // set the value of the HPS GPIO1 bits attached to LCD RESETn to zero
    alt_clrbits_word( ( virtual_base + ( ( uint32_t )( ALT_GPIO1_SWPORTA_DR_ADDR ) & ( uint32_t )( HW_REGS_MASK ) ) ), HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
    usleep( 1000000 / 16 );    
    // set the value of the HPS GPIO1 bits attached to LCD RESETn to one
    alt_setbits_word( ( virtual_base + ( ( uint32_t )( ALT_GPIO1_SWPORTA_DR_ADDR ) & ( uint32_t )( HW_REGS_MASK ) ) ), HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
    usleep( 1000000 / 16 );    
    
    ////////////////////////////////////////////////////
    ////////////////////////////////////////////////////
    ////////////////////////////////////////////////////
    //////// turn-on backlight
    // set the direction of the HPS GPIO1 bits attached to LCD Backlight to output
    alt_setbits_word( ( virtual_base + ( ( uint32_t )( ALT_GPIO1_SWPORTA_DDR_ADDR ) & ( uint32_t )( HW_REGS_MASK ) ) ), HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1 );
    // set the value of the HPS GPIO1 bits attached to LCD Backlight to ZERO, turn OFF the Backlight
    alt_clrbits_word( ( virtual_base + ( ( uint32_t )( ALT_GPIO1_SWPORTA_DR_ADDR ) & ( uint32_t )( HW_REGS_MASK ) ) ), HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1 );

I modifed the above to this that does not use the virtual_base and replaced the usleep with a simple for loop:

# define HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1       ( 0x00080000 )  # define HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1    ( 0x00000800 )
// set the direction of the HPS GPIO1 bits attached to LCD RESETn to output
alt_setbits_word(ALT_GPIO1_SWPORTA_DDR_ADDR, HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
// set the value of the HPS GPIO1 bits attached to LCD RESETn to zero
alt_clrbits_word(ALT_GPIO1_SWPORTA_DR_ADDR, HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
for (int i = 0 ; i < 50000; i++);
// set the value of the HPS GPIO1 bits attached to LCD RESETn to one
alt_setbits_word(ALT_GPIO1_SWPORTA_DR_ADDR, HPS_LCM_RESETn_BIT_GPIObit48_GPIOreg1 );
for (int i = 0 ; i < 50000; i++);
    
// set the direction of the HPS GPIO1 bits attached to LCD Backlight to output
alt_setbits_word(ALT_GPIO1_SWPORTA_DDR_ADDR, HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1 );
// set the value of the HPS GPIO1 bits attached to LCD Backlight to ZERO, turn OFF the Backlight
alt_clrbits_word(ALT_GPIO1_SWPORTA_DR_ADDR, HPS_LCM_BACKLIHGT_BIT_GPIObit40_GPIOreg1 );

It does not work. I tried clearing and setting the LCD backlight bit, but nothing happens. Am I missing something?