thermosphere: add qemu support

thermosphere/src/platform/qemu/uart.c

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "uart.h"
+#include "../../utils.h"
+
+// Adapted from ARM TF asm code
+// AMBA PL101 driver
+
+/*
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+//115200
+
+void uartInit(u32 baudRate)
+{
+    // First, disable UART
+    g_uartRegs->CR &= ~PL011_UARTCR_UARTEN;
+
+    // Set baudrate, Divisor =  (Uart clock * 4) / baudrate; stored in IBRD|FBRD
+    u32 divisor = (4 * UART0_CLK_IN_HZ) / baudRate;
+    g_uartRegs->IBRD = divisor >> 6;
+    g_uartRegs->FBRD = divisor & 0x3F;
+    g_uartRegs->LCR_H = PL011_LINE_CONTROL;
+
+    // Clear any pending errors
+    g_uartRegs->ECR = 0;
+
+    // Enable tx, rx, and uart overall
+    g_uartRegs->CR = PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN;
+}
+
+void uartWriteData(const void *buffer, size_t size)
+{
+    const u8 *buf8 = (const u8 *)buffer;
+    for (size_t i = 0; i < size; i++) {
+        while (g_uartRegs->FR & PL011_UARTFR_TXFF); // while TX FIFO full
+        g_uartRegs->DR = buf8[i]; 
+    }
+}
+
+void uartReadData(void *buffer, size_t size)
+{
+    u8 *buf8 = (u8 *)buffer;
+    size_t i;
+
+    for (i = 0; i < size; i++) {
+        while (g_uartRegs->FR & PL011_UARTFR_RXFE);
+        buf8[i] = g_uartRegs->DR;
+    }
+}
+
+size_t uartReadDataMax(void *buffer, size_t maxSize)
+{
+    u8 *buf8 = (u8 *)buffer;
+    size_t i;
+
+    for (i = 0; i < maxSize && !(g_uartRegs->FR & PL011_UARTFR_RXFE); i++) {
+        buf8[i] = g_uartRegs->DR;
+    }
+
+    return 1 + i;
+}