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Commit fce5f750 authored by Soby Mathew's avatar Soby Mathew
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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
parent 592dd7cb
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drivers/arm/pl011/pl011.c deleted 100644 → 0
View file @ 592dd7cb
/*
* 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);
}
drivers/arm/pl011/pl011_console.c → drivers/arm/pl011/pl011_console.S
View file @ fce5f750
......@@ -27,72 +27,149 @@
* 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 <arch.h>
#include <asm_macros.S>
#include <pl011.h>
static unsigned long uart_base;
.globl console_init
.globl console_putc
.globl console_core_init
.globl console_core_putc
.globl console_getc
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.
/*
* 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.
*/
assert(base_addr);
.section .data.console_base ; .align 3
console_base: .quad 0x0
/* Initialise internal base address variable */
uart_base = base_addr;
/* ---------------------------------------------
* 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
/* Baud Rate */
/* ---------------------------------------------
* 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)
pl011_write_ibrd(uart_base, PL011_INTEGER);
pl011_write_fbrd(uart_base, PL011_FRACTIONAL);
mov w1, #PL011_INTEGER
str w1, [x0, #UARTIBRD]
mov w1, #PL011_FRACTIONAL
str w1, [x0, #UARTFBRD]
#else
pl011_setbaudrate(uart_base, PL011_BAUDRATE);
.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
pl011_write_lcr_h(uart_base, PL011_LINE_CONTROL);
mov w1, #PL011_LINE_CONTROL
str w1, [x0, #UARTLCR_H]
/* Clear any pending errors */
pl011_write_ecr(uart_base, 0);
str wzr, [x0, #UARTECR]
/* Enable tx, rx, and uart overall */
pl011_write_cr(uart_base, PL011_UARTCR_RXE | PL011_UARTCR_TXE |
PL011_UARTCR_UARTEN);
mov w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
str w1, [x0, #UARTCR]
mov w0, #1
init_fail:
ret
}
#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
/* ---------------------------------------------
* 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
* ---------------------------------------------
*/
if (!uart_base)
return -1;
if (c == '\n') {
WAIT_UNTIL_UART_FREE(uart_base);
pl011_write_dr(uart_base, '\r');
}
func console_putc
adrp x2, console_base
ldr x1, [x2, :lo12:console_base]
b console_core_putc
WAIT_UNTIL_UART_FREE(uart_base);
pl011_write_dr(uart_base, c);
return c;
}
int console_getc(void)
{
assert(uart_base);
/* --------------------------------------------------------
* 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
while ((pl011_read_fr(uart_base) & PL011_UARTFR_RXFE) != 0)
;
return pl011_read_dr(uart_base);
}
/* ---------------------------------------------
* 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
include/drivers/arm/pl011.h
View file @ fce5f750
......@@ -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__ */
plat/fvp/platform.mk
View file @ fce5f750
......@@ -45,8 +45,7 @@ $(eval $(call add_define,TSP_RAM_LOCATION_ID))
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 \
......
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