Nonworking SD card code for AVR

tinysd.c

#include <avr/io.h>
#include <util/delay.h>

// Some serial comms stuff; just using for debugging
#include "uart.h"

typedef unsigned char byte;

byte spi(byte b); // Send / receive one byte over SPI
void sd_select(int high); // Set SD CS pin high or low
int sd_command(byte cmd, uint32_t arg); // Send one command / arg pair to the SD card
byte sd_wait(); // Wait a max of 3 sec for the card not to be busy

int main(){
    initUSART();

    DDRB |= (1 << 2); // SD CS pin
    PORTB |= (1 << 2); /* start off not selected (high) */

    DDRB |= (1 << 3);  /* output on MOSI */
    PORTB |= (1 << 4); /* pullup on MISO */
    DDRB |= (1 << 5);  /* output on SCK */

    SPCR |= (1 << SPR0) | (1 << SPR1); /* div 128 */
    SPCR |= (1 << MSTR); /* clockmaster */
    SPCR |= (1 << SPE);  /* enable */

    while(1){
        receiveByte();

        // Throw a bunch of cycles with CS high at it
        sd_select(1);
        for(int k=0; k < 10; k++) spi(0xFF);

        sd_select(0); // Start the command

        printStringHex("Wait: ", sd_wait());
        printStringHex("Enter idle state: ", sd_command(0x00, 0));
        
        sd_select(1); // end command
    }

    return 0;
}

////////////////////////////////////////////////////////////

byte spi(byte b) {
    SPDR = b;
    loop_until_bit_is_set(SPSR, SPIF); /* wait until done */
    return SPDR; /* SPDR now contains the received byte */
}

void sd_select(int high){
    if(high) DDRB |=  (1 << 2);
    else     DDRB &= ~(1 << 2);
}

int sd_command(byte cmd, uint32_t arg){
    spi(cmd | 0x40);

    spi(arg >> 24);
    spi(arg >> 16);
    spi(arg >> 8);
    spi(arg);

    byte crc = 0xFF;
    if (cmd == 0x00) crc = 0x95;
    if (cmd == 0x08) crc = 0x87;
    spi(crc);

    int count = 0;
    while(1){
        byte status = spi(0xff);

        if(!(status & 0x80)) return status;
        if(count++ > 300) return status;
    }
}

byte sd_wait() {
    int count = 0;
    while(1) {
        if(spi(0xFF) == 0xFF) return 1;
        if(count++ > 300) return 0;
        _delay_ms(10);
    }
}