Introduce asm console functions in TF
This patch replaces the pl011 console family of functions
with their equivalents defined in assembly. The baud rate is
defined by the PL011_BAUDRATE macro and IBRD and FBRD values
for pl011 are computed statically. This patch will enable
us to invoke the console functions without the C Runtime Stack.
Change-Id: Ic3f7b7370ded38bf9020bf746b362081b76642c7
diff --git a/drivers/arm/pl011/pl011.c b/drivers/arm/pl011/pl011.c
deleted file mode 100644
index e296c23..0000000
--- a/drivers/arm/pl011/pl011.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <assert.h>
-#include <pl011.h>
-
-void pl011_setbaudrate(unsigned long base_addr, unsigned int baudrate)
-{
- unsigned int divisor;
- assert(baudrate);
- divisor = (PL011_CLK_IN_HZ * 4) / baudrate;
- pl011_write_ibrd(base_addr, divisor >> 6);
- pl011_write_fbrd(base_addr, divisor & 0x3F);
-}
diff --git a/drivers/arm/pl011/pl011_console.S b/drivers/arm/pl011/pl011_console.S
new file mode 100644
index 0000000..bf26b6b
--- /dev/null
+++ b/drivers/arm/pl011/pl011_console.S
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <arch.h>
+#include <asm_macros.S>
+#include <pl011.h>
+
+ .globl console_init
+ .globl console_putc
+ .globl console_core_init
+ .globl console_core_putc
+ .globl console_getc
+
+ /*
+ * The console base is in the data section and not in .bss
+ * even though it is zero-init. In particular, this allows
+ * the console functions to start using this variable before
+ * the runtime memory is initialized for images which do not
+ * need to copy the .data section from ROM to RAM.
+ */
+.section .data.console_base ; .align 3
+ console_base: .quad 0x0
+
+ /* ---------------------------------------------
+ * int console_init(unsigned long base_addr)
+ * Function to initialize the console without a
+ * C Runtime to print debug information. It saves
+ * the console base to the data section.
+ * In: x0 - console base address
+ * out: return 1 on success.
+ * Clobber list : x1, x2
+ * ---------------------------------------------
+ */
+func console_init
+ adrp x1, console_base
+ str x0, [x1, :lo12:console_base]
+ b console_core_init
+
+ /* ---------------------------------------------
+ * int console_core_init(unsigned long base_addr)
+ * Function to initialize the console without a
+ * C Runtime to print debug information. This
+ * function will be accessed by console_init and
+ * crash reporting.
+ * In: x0 - console base address
+ * Out: return 1 on success
+ * Clobber list : x1, x2
+ * ---------------------------------------------
+ */
+func console_core_init
+ /* Check the input base address */
+ cbz x0, init_fail
+ /* Program the baudrate */
+#if defined(PL011_INTEGER) && defined(PL011_FRACTIONAL)
+ mov w1, #PL011_INTEGER
+ str w1, [x0, #UARTIBRD]
+ mov w1, #PL011_FRACTIONAL
+ str w1, [x0, #UARTFBRD]
+#else
+.set BRD, ((PL011_CLK_IN_HZ << 2) / PL011_BAUDRATE)
+ /* Write the IBRD */
+ mov w1, #((BRD >> 6) & 0xffff)
+.if BRD>=0x400000
+ movk w1, #(BRD >> 22), LSL #16
+.endif
+ str w1, [x0, #UARTIBRD]
+ /* Write the FBRD */
+ mov w1, #(BRD & 0x3f)
+ str w1, [x0, #UARTFBRD]
+#endif
+ mov w1, #PL011_LINE_CONTROL
+ str w1, [x0, #UARTLCR_H]
+ /* Clear any pending errors */
+ str wzr, [x0, #UARTECR]
+ /* Enable tx, rx, and uart overall */
+ mov w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
+ str w1, [x0, #UARTCR]
+ mov w0, #1
+init_fail:
+ ret
+
+ /* ---------------------------------------------
+ * int console_putc(int c)
+ * Function to output a character over the
+ * console. It returns the character printed on
+ * success or -1 on error.
+ * In : x0 - character to be printed
+ * Out : return -1 on error else return character.
+ * Clobber list : x1, x2
+ * ---------------------------------------------
+ */
+func console_putc
+ adrp x2, console_base
+ ldr x1, [x2, :lo12:console_base]
+ b console_core_putc
+
+ /* --------------------------------------------------------
+ * int console_core_putc(int c, unsigned long base_addr)
+ * Function to output a character over the console. It
+ * returns the character printed on success or -1 on error.
+ * In : x0 - character to be printed
+ * x1 - console base address
+ * Out : return -1 on error else return character.
+ * Clobber list : x2
+ * --------------------------------------------------------
+ */
+func console_core_putc
+ /* Check the input parameter */
+ cbz x1, putc_error
+ /* Prepend '\r' to '\n' */
+ cmp x0, #0xA
+ b.ne 2f
+1:
+ /* Check if the transmit FIFO is full */
+ ldr w2, [x1, #UARTFR]
+ tbnz w2, #PL011_UARTFR_TXFF_BIT, 1b
+ mov w2, #0xD
+ str w2, [x1, #UARTDR]
+2:
+ /* Check if the transmit FIFO is full */
+ ldr w2, [x1, #UARTFR]
+ tbnz w2, #PL011_UARTFR_TXFF_BIT, 2b
+ str w0, [x1, #UARTDR]
+ ret
+putc_error:
+ mov w0, #-1
+ ret
+
+ /* ---------------------------------------------
+ * int console_getc(void)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * or -1 on error.
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_getc
+ adrp x0, console_base
+ ldr x1, [x0, :lo12:console_base]
+ cbz x1, getc_error
+1:
+ /* Check if the receive FIFO is empty */
+ ldr w0, [x1, #UARTFR]
+ tbnz w0, #PL011_UARTFR_RXFE_BIT, 1b
+ ldr w0, [x1, #UARTDR]
+ ret
+getc_error:
+ mov w0, #-1
+ ret
diff --git a/drivers/arm/pl011/pl011_console.c b/drivers/arm/pl011/pl011_console.c
deleted file mode 100644
index 81897ca..0000000
--- a/drivers/arm/pl011/pl011_console.c
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <assert.h>
-#include <console.h>
-#include <pl011.h>
-
-static unsigned long uart_base;
-
-void console_init(unsigned long base_addr)
-{
- /* TODO: assert() internally calls printf() and will result in
- * an infinite loop. This needs to be fixed with some kind of
- * exception mechanism or early panic support. This also applies
- * to the other assert() calls below.
- */
- assert(base_addr);
-
- /* Initialise internal base address variable */
- uart_base = base_addr;
-
- /* Baud Rate */
-#if defined(PL011_INTEGER) && defined(PL011_FRACTIONAL)
- pl011_write_ibrd(uart_base, PL011_INTEGER);
- pl011_write_fbrd(uart_base, PL011_FRACTIONAL);
-#else
- pl011_setbaudrate(uart_base, PL011_BAUDRATE);
-#endif
-
- pl011_write_lcr_h(uart_base, PL011_LINE_CONTROL);
-
- /* Clear any pending errors */
- pl011_write_ecr(uart_base, 0);
-
- /* Enable tx, rx, and uart overall */
- pl011_write_cr(uart_base, PL011_UARTCR_RXE | PL011_UARTCR_TXE |
- PL011_UARTCR_UARTEN);
-
-}
-
-#define WAIT_UNTIL_UART_FREE(base) \
- while ((pl011_read_fr(base) & PL011_UARTFR_TXFF)) \
- continue
-
-int console_putc(int c)
-{
- /* If the console has not been initialized then return an error
- * code. Asserting here would result in recursion and stack
- * exhaustion
- */
- if (!uart_base)
- return -1;
-
- if (c == '\n') {
- WAIT_UNTIL_UART_FREE(uart_base);
- pl011_write_dr(uart_base, '\r');
- }
-
- WAIT_UNTIL_UART_FREE(uart_base);
- pl011_write_dr(uart_base, c);
- return c;
-}
-
-int console_getc(void)
-{
- assert(uart_base);
-
- while ((pl011_read_fr(uart_base) & PL011_UARTFR_RXFE) != 0)
- ;
- return pl011_read_dr(uart_base);
-}
diff --git a/include/drivers/arm/pl011.h b/include/drivers/arm/pl011.h
index 281330e..e01d8b2 100644
--- a/include/drivers/arm/pl011.h
+++ b/include/drivers/arm/pl011.h
@@ -31,9 +31,6 @@
#ifndef __PL011_H__
#define __PL011_H__
-#include <mmio.h>
-
-
/* PL011 Registers */
#define UARTDR 0x000
#define UARTRSR 0x004
@@ -68,6 +65,9 @@
#define PL011_UARTFR_DSR (1 << 1) /* Data set ready */
#define PL011_UARTFR_CTS (1 << 0) /* Clear to send */
+#define PL011_UARTFR_TXFF_BIT 5 /* Transmit FIFO full bit in UARTFR register */
+#define PL011_UARTFR_RXFE_BIT 4 /* Receive FIFO empty bit in UARTFR register */
+
/* Control reg bits */
#define PL011_UARTCR_CTSEN (1 << 15) /* CTS hardware flow control enable */
#define PL011_UARTCR_RTSEN (1 << 14) /* RTS hardware flow control enable */
@@ -103,58 +103,4 @@
#define PL011_UARTLCR_H_PEN (1 << 1) /* Parity Enable */
#define PL011_UARTLCR_H_BRK (1 << 0) /* Send break */
-/*******************************************************************************
- * Pl011 CPU interface accessors for writing registers
- ******************************************************************************/
-
-static inline void pl011_write_ibrd(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTIBRD, val);
-}
-
-static inline void pl011_write_fbrd(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTFBRD, val);
-}
-
-static inline void pl011_write_lcr_h(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTLCR_H, val);
-}
-
-static inline void pl011_write_ecr(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTECR, val);
-}
-
-static inline void pl011_write_cr(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTCR, val);
-}
-
-static inline void pl011_write_dr(unsigned long base, unsigned int val)
-{
- mmio_write_32(base + UARTDR, val);
-}
-
-/*******************************************************************************
- * Pl011 CPU interface accessors for reading registers
- ******************************************************************************/
-
-static inline unsigned int pl011_read_fr(unsigned long base)
-{
- return mmio_read_32(base + UARTFR);
-}
-
-static inline unsigned int pl011_read_dr(unsigned long base)
-{
- return mmio_read_32(base + UARTDR);
-}
-
-/*******************************************************************************
- * Function prototypes
- ******************************************************************************/
-
-void pl011_setbaudrate(unsigned long base_addr, unsigned int baudrate);
-
#endif /* __PL011_H__ */
diff --git a/plat/fvp/platform.mk b/plat/fvp/platform.mk
index b22a339..f6275b7 100644
--- a/plat/fvp/platform.mk
+++ b/plat/fvp/platform.mk
@@ -45,8 +45,7 @@
PLAT_INCLUDES := -Iplat/fvp/include/
-PLAT_BL_COMMON_SOURCES := drivers/arm/pl011/pl011.c \
- drivers/arm/pl011/pl011_console.c \
+PLAT_BL_COMMON_SOURCES := drivers/arm/pl011/pl011_console.S \
drivers/io/io_fip.c \
drivers/io/io_memmap.c \
drivers/io/io_semihosting.c \