rpi start. doesn't work

hw/mcu/broadcom/bcm2711/io.c

@@ -0,0 +1,168 @@
+// From: https://github.com/isometimes/rpi4-osdev/blob/master/part4-miniuart/io.c
+// CC-0 License
+
+// GPIO
+
+enum {
+    PERIPHERAL_BASE = 0xFE000000,
+    GPFSEL0         = PERIPHERAL_BASE + 0x200000,
+    GPSET0          = PERIPHERAL_BASE + 0x20001C,
+    GPCLR0          = PERIPHERAL_BASE + 0x200028,
+    GPPUPPDN0       = PERIPHERAL_BASE + 0x2000E4
+};
+
+enum {
+    GPIO_MAX_PIN       = 53,
+    GPIO_FUNCTION_OUT  = 1,
+    GPIO_FUNCTION_ALT5 = 2,
+    GPIO_FUNCTION_ALT3 = 7
+};
+
+enum {
+    Pull_None = 0,
+    Pull_Down = 1, // Are down and up the right way around?
+    Pull_Up = 2
+};
+
+void mmio_write(long reg, unsigned int val) { *(volatile unsigned int *)reg = val; }
+unsigned int mmio_read(long reg) { return *(volatile unsigned int *)reg; }
+
+unsigned int gpio_call(unsigned int pin_number, unsigned int value, unsigned int base, unsigned int field_size, unsigned int field_max) {
+    unsigned int field_mask = (1 << field_size) - 1;
+  
+    if (pin_number > field_max) return 0;
+    if (value > field_mask) return 0; 
+
+    unsigned int num_fields = 32 / field_size;
+    unsigned int reg = base + ((pin_number / num_fields) * 4);
+    unsigned int shift = (pin_number % num_fields) * field_size;
+
+    unsigned int curval = mmio_read(reg);
+    curval &= ~(field_mask << shift);
+    curval |= value << shift;
+    mmio_write(reg, curval);
+
+    return 1;
+}
+
+unsigned int gpio_set     (unsigned int pin_number, unsigned int value) { return gpio_call(pin_number, value, GPSET0, 1, GPIO_MAX_PIN); }
+unsigned int gpio_clear   (unsigned int pin_number, unsigned int value) { return gpio_call(pin_number, value, GPCLR0, 1, GPIO_MAX_PIN); }
+unsigned int gpio_pull    (unsigned int pin_number, unsigned int value) { return gpio_call(pin_number, value, GPPUPPDN0, 2, GPIO_MAX_PIN); }
+unsigned int gpio_function(unsigned int pin_number, unsigned int value) { return gpio_call(pin_number, value, GPFSEL0, 3, GPIO_MAX_PIN); }
+
+void gpio_useAsAlt3(unsigned int pin_number) {
+    gpio_pull(pin_number, Pull_None);
+    gpio_function(pin_number, GPIO_FUNCTION_ALT3);
+}
+
+void gpio_useAsAlt5(unsigned int pin_number) {
+    gpio_pull(pin_number, Pull_None);
+    gpio_function(pin_number, GPIO_FUNCTION_ALT5);
+}
+
+void gpio_initOutputPinWithPullNone(unsigned int pin_number) {
+    gpio_pull(pin_number, Pull_None);
+    gpio_function(pin_number, GPIO_FUNCTION_OUT);
+}
+
+void gpio_setPinOutputBool(unsigned int pin_number, unsigned int onOrOff) {
+    if (onOrOff) {
+        gpio_set(pin_number, 1);
+    } else {
+        gpio_clear(pin_number, 1);
+    }
+}
+
+// UART
+
+enum {
+    AUX_BASE        = PERIPHERAL_BASE + 0x215000,
+    AUX_IRQ         = AUX_BASE,
+    AUX_ENABLES     = AUX_BASE + 4,
+    AUX_MU_IO_REG   = AUX_BASE + 64,
+    AUX_MU_IER_REG  = AUX_BASE + 68,
+    AUX_MU_IIR_REG  = AUX_BASE + 72,
+    AUX_MU_LCR_REG  = AUX_BASE + 76,
+    AUX_MU_MCR_REG  = AUX_BASE + 80,
+    AUX_MU_LSR_REG  = AUX_BASE + 84,
+    AUX_MU_MSR_REG  = AUX_BASE + 88,
+    AUX_MU_SCRATCH  = AUX_BASE + 92,
+    AUX_MU_CNTL_REG = AUX_BASE + 96,
+    AUX_MU_STAT_REG = AUX_BASE + 100,
+    AUX_MU_BAUD_REG = AUX_BASE + 104,
+    AUX_UART_CLOCK  = 500000000,
+    UART_MAX_QUEUE  = 16 * 1024
+};
+
+#define AUX_MU_BAUD(baud) ((AUX_UART_CLOCK/(baud*8))-1)
+
+unsigned char uart_output_queue[UART_MAX_QUEUE];
+unsigned int uart_output_queue_write = 0;
+unsigned int uart_output_queue_read = 0;
+
+void uart_init(void) {
+    mmio_write(AUX_ENABLES, 1); //enable UART1
+    mmio_write(AUX_MU_IER_REG, 0);
+    mmio_write(AUX_MU_CNTL_REG, 0);
+    mmio_write(AUX_MU_LCR_REG, 3); //8 bits
+    mmio_write(AUX_MU_MCR_REG, 0);
+    mmio_write(AUX_MU_IER_REG, 0);
+    mmio_write(AUX_MU_IIR_REG, 0xC6); //disable interrupts
+    mmio_write(AUX_MU_BAUD_REG, AUX_MU_BAUD(115200));
+    gpio_useAsAlt5(14);
+    gpio_useAsAlt5(15);
+    mmio_write(AUX_MU_CNTL_REG, 3); //enable RX/TX
+}
+
+unsigned int uart_isOutputQueueEmpty(void) {
+    return uart_output_queue_read == uart_output_queue_write;
+}
+
+unsigned int uart_isReadByteReady(void)  { return mmio_read(AUX_MU_LSR_REG) & 0x01; }
+unsigned int uart_isWriteByteReady(void) { return mmio_read(AUX_MU_LSR_REG) & 0x20; }
+
+unsigned char uart_readByte(void) {
+    while (!uart_isReadByteReady());
+    return (unsigned char)mmio_read(AUX_MU_IO_REG);
+}
+
+void uart_writeByteBlockingActual(unsigned char ch) {
+    while (!uart_isWriteByteReady()); 
+    mmio_write(AUX_MU_IO_REG, (unsigned int)ch);
+}
+
+void uart_loadOutputFifo(void) {
+    while (!uart_isOutputQueueEmpty() && uart_isWriteByteReady()) {
+        uart_writeByteBlockingActual(uart_output_queue[uart_output_queue_read]);
+        uart_output_queue_read = (uart_output_queue_read + 1) & (UART_MAX_QUEUE - 1); // Don't overrun
+    }
+}
+
+void uart_writeByteBlocking(unsigned char ch) {
+    unsigned int next = (uart_output_queue_write + 1) & (UART_MAX_QUEUE - 1); // Don't overrun
+
+    while (next == uart_output_queue_read) uart_loadOutputFifo();
+
+    uart_output_queue[uart_output_queue_write] = ch;
+    uart_output_queue_write = next;
+}
+
+void uart_writeText(const char *buffer) {
+    while (*buffer) {
+       if (*buffer == '\n') uart_writeByteBlocking('\r');
+       uart_writeByteBlocking(*buffer++);
+    }
+}
+
+void uart_drainOutputQueue(void) {
+    while (!uart_isOutputQueueEmpty()) uart_loadOutputFifo();
+}
+
+void uart_update(void) {
+    uart_loadOutputFifo();
+
+    if (uart_isReadByteReady()) {
+       unsigned char ch = uart_readByte();
+       if (ch == '\r') uart_writeText("\n"); else uart_writeByteBlocking(ch);
+    }
+}