[Minios-devel] [UNIKRAFT PATCHv5 20/46] plat/common: Add early debug console library for Arm64

[Wei Chen <wei.chen@xxxxxxx>]

From: Wei Chen <Wei.Chen@xxxxxxx>

PL011 UART is used frequently for virtual machine or bare metal,
so we implement a simple PL011 device driver library for early
debug console. Unikraft Kconfig provides a KVM_EARLY_DEBUG_PL011_UART
for early debug console UART address. If users want to enable PL011
for early debug, they can configure the base address in this variable.

Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
---
 plat/common/arm/console.c | 139 ++++++++++++++++++++++++++++++++++++++
 plat/kvm/Makefile.uk      |   3 +
 plat/kvm/arm/setup.c      |   2 +-
 3 files changed, 143 insertions(+), 1 deletion(-)
 create mode 100644 plat/common/arm/console.c

diff --git a/plat/common/arm/console.c b/plat/common/arm/console.c
new file mode 100644
index 0000000..5d1b5d4
--- /dev/null
+++ b/plat/common/arm/console.c
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Authors: Wei Chen <Wei.Chen@xxxxxxx>
+ *
+ * Copyright (c) 2018 Arm Ltd.
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <uk/plat/console.h>
+#include <uk/assert.h>
+#include <arm/cpu.h>
+
+/* PL011 UART registers and masks*/
+/* Data register */
+#define REG_UARTDR_OFFSET      0x00
+
+/* Receive status register/error clear register */
+#define REG_UARTRSR_OFFSET     0x04
+#define REG_UARTECR_OFFSET     0x04
+
+/* Flag register */
+#define REG_UARTFR_OFFSET      0x18
+#define FR_TXFF                        (1 << 5)    /* Transmit FIFO/reg full */
+#define FR_RXFE                        (1 << 4)    /* Receive FIFO/reg empty */
+
+/* Integer baud rate register */
+#define REG_UARTIBRD_OFFSET    0x24
+/* Fractional baud rate register */
+#define REG_UARTFBRD_OFFSET    0x28
+
+/* Line control register */
+#define REG_UARTLCR_H_OFFSET   0x2C
+#define LCR_H_WLEN8            (0x3 << 5)  /* Data width is 8-bits */
+
+/* Control register */
+#define REG_UARTCR_OFFSET      0x30
+#define CR_RXE                 (1 << 9)    /* Receive enable */
+#define CR_TXE                 (1 << 8)    /* Transmit enable */
+#define CR_UARTEN              (1 << 0)    /* UART enable */
+
+/* Interrupt FIFO level select register */
+#define REG_UARTIFLS_OFFSET    0x34
+/* Interrupt mask set/clear register */
+#define REG_UARTIMSC_OFFSET    0x38
+/* Raw interrupt status register */
+#define REG_UARTRIS_OFFSET     0x3C
+/* Masked interrupt status register */
+#define REG_UARTMIS_OFFSET     0x40
+/* Interrupt clear register */
+#define REG_UARTICR_OFFSET     0x44
+
+ /* PL011 UART base address */
+#if defined(CONFIG_KVM_EARLY_DEBUG_PL011_UART)
+static uint64_t pl011_uart_bas = CONFIG_KVM_EARLY_DEBUG_PL011_UART;
+#else
+static uint64_t pl011_uart_bas;
+#endif
+
+/* Macros to access PL011 Registers with base address */
+#define PL011_REG(r)           ((uint16_t *)(pl011_uart_bas + (r)))
+#define PL011_REG_READ(r)      ioreg_read16(PL011_REG(r))
+#define PL011_REG_WRITE(r, v)  ioreg_write16(PL011_REG(r), v)
+
+int ukplat_coutd(const char *str, uint32_t len)
+{
+       return ukplat_coutk(str, len);
+}
+
+static void pl011_write(char a)
+{
+       /*
+        * Avoid using the UART before base address initialized,
+        * or CONFIG_KVM_EARLY_DEBUG_PL011_UART doesn't be enabled.
+        */
+       if (!pl011_uart_bas)
+               return;
+
+       /* Wait until TX FIFO becomes empty */
+       while (PL011_REG_READ(REG_UARTFR_OFFSET) & FR_TXFF)
+               ;
+
+       PL011_REG_WRITE(REG_UARTDR_OFFSET, a & 0xff);
+}
+
+static void pl011_putc(char a)
+{
+       if (a == '\n')
+               pl011_write('\r');
+       pl011_write(a);
+}
+
+/* Try to get data from pl011 UART without blocking */
+static int pl011_getc(void)
+{
+       /*
+        * Avoid using the UART before base address initialized,
+        * or CONFIG_KVM_EARLY_DEBUG_PL011_UART doesn't be enabled.
+        */
+       if (!pl011_uart_bas)
+               return -1;
+
+       /* If RX FIFO is empty, return -1 immediately */
+       if (PL011_REG_READ(REG_UARTFR_OFFSET) & FR_RXFE)
+               return -1;
+
+       return (int) (PL011_REG_READ(REG_UARTDR_OFFSET) & 0xff);
+}
+
+int ukplat_coutk(const char *buf, unsigned int len)
+{
+       for (unsigned int i = 0; i < len; i++)
+               pl011_putc(buf[i]);
+       return len;
+}
+
+int ukplat_cink(char *buf, unsigned int maxlen)
+{
+       int ret;
+       unsigned int num = 0;
+
+       while (num < maxlen && (ret = pl011_getc()) >= 0) {
+               *(buf++) = (char) ret;
+               num++;
+       }
+
+       return (int) num;
+}
diff --git a/plat/kvm/Makefile.uk b/plat/kvm/Makefile.uk
index 9f2a01f..4ec90f3 100644
--- a/plat/kvm/Makefile.uk
+++ b/plat/kvm/Makefile.uk
@@ -49,6 +49,9 @@ endif
 ## Architecture library definitions for arm64
 ##
 ifeq ($(CONFIG_ARCH_ARM_64),y)
+ifeq ($(findstring y,$(CONFIG_KVM_KERNEL_SERIAL_CONSOLE) 
$(CONFIG_KVM_DEBUG_SERIAL_CONSOLE)),y)
+LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += 
$(UK_PLAT_COMMON_BASE)/arm/console.c|common
+endif
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += $(LIBKVMPLAT_BASE)/arm/entry64.S
 LIBKVMPLAT_SRCS-$(CONFIG_ARCH_ARM_64) += $(LIBKVMPLAT_BASE)/arm/setup.c
 endif
diff --git a/plat/kvm/arm/setup.c b/plat/kvm/arm/setup.c
index 2fc4538..e2ece8e 100644
--- a/plat/kvm/arm/setup.c
+++ b/plat/kvm/arm/setup.c
@@ -22,5 +22,5 @@
 
 void _libkvmplat_start(void *dtb_pointer)
 {
-       UK_BUG();
+       uk_printd(DLVL_INFO, "Entering from KVM (arm64)...\n");
 }
-- 
2.17.1


_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel