fusee: Complete re-write of the hardware initialization code:

- Updated code to match hekate's;
- Improved nxboot (now boots firmwares 2.x successfully);
- Temporarily disabled built-in boot system module support;
- Fixed multiple bugs.

fusee/fusee-primary/src/uart.c

@@ -0,0 +1,55 @@
+#include "uart.h"
+#include "timers.h"
+
+void uart_init(UartDevice dev, uint32_t baud) {
+    volatile tegra_uart_t *uart = uart_get_regs(dev);
+
+    /* Set baud rate. */
+    uint32_t rate = (8 * baud + 408000000) / (16 * baud);
+    uart->UART_LCR = UART_LCR_DLAB; /* Enable DLAB. */
+    uart->UART_THR_DLAB = (uint8_t)rate; /* Divisor latch LSB. */
+    uart->UART_IER_DLAB = (uint8_t)(rate >> 8); /* Divisor latch MSB. */
+    uart->UART_LCR = 0; /* Diable DLAB. */
+
+    /* Setup UART in fifo mode. */
+    uart->UART_IER_DLAB = 0;
+    uart->UART_IIR_FCR = UART_FCR_FCR_EN_FIFO | UART_FCR_RX_CLR | UART_FCR_TX_CLR; /* Enable and clear TX and RX FIFOs. */
+    (void)uart->UART_LSR;
+    udelay(3 * ((baud + 999999) / baud));
+    uart->UART_LCR = UART_LCR_WD_LENGTH_8; /* Set word length 8. */
+    uart->UART_MCR = 0;
+    uart->UART_MSR = 0;
+    uart->UART_IRDA_CSR = 0;
+    uart->UART_RX_FIFO_CFG = 1; /* Set RX_FIFO trigger level */
+    uart->UART_MIE = 0;
+    uart->UART_ASR = 0;
+}
+
+/* This function blocks until the UART device (dev) is in the desired state (status). Make sure the desired state can be reached! */
+void uart_wait_idle(UartDevice dev, UartVendorStatus status) {
+    while (!(uart_get_regs(dev)->UART_VENDOR_STATUS & status)) {
+        /* Wait */
+    }
+}
+
+void uart_send(UartDevice dev, const void *buf, size_t len) {
+    volatile tegra_uart_t *uart = uart_get_regs(dev);
+
+    for (size_t i = 0; i < len; i++) {
+        while (uart->UART_LSR & UART_LSR_TX_FIFO_FULL) {
+            /* Wait until the TX FIFO isn't full */
+        }
+        uart->UART_THR_DLAB = *((const uint8_t *)buf + i);
+    }
+}
+
+void uart_recv(UartDevice dev, void *buf, size_t len) {
+    volatile tegra_uart_t *uart = uart_get_regs(dev);
+
+    for (size_t i = 0; i < len; i++) {
+        while (uart->UART_LSR & UART_LSR_RX_FIFO_EMPTY) {
+            /* Wait until the RX FIFO isn't empty */
+        }
+        *((uint8_t *)buf + i) = uart->UART_THR_DLAB;
+    }
+}