console: Port Multi Console driver to AArch32

The old driver is now in deprecated_console.S, in a similar way to the
AArch64 driver.

Change-Id: Ib57209c322576c451d466d7406a94adbf01ab8fd
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>

Makefile

@@ -416,12 +416,6 @@ ifeq ($(HW_ASSISTED_COHERENCY)-$(USE_COHERENT_MEM),1-1)
 $(error USE_COHERENT_MEM cannot be enabled with HW_ASSISTED_COHERENCY)
 endif
 
-ifneq ($(MULTI_CONSOLE_API), 0)
-    ifeq (${ARCH},aarch32)
-        $(error "Error: MULTI_CONSOLE_API is not supported for AArch32")
-    endif
-endif
-
 #For now, BL2_IN_XIP_MEM is only supported when BL2_AT_EL3 is 1.
 ifeq ($(BL2_AT_EL3)-$(BL2_IN_XIP_MEM),0-1)
 $(error "BL2_IN_XIP_MEM is only supported when BL2_AT_EL3 is enabled")

drivers/console/aarch32/console.S

@@ -3,104 +3,9 @@
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
-#include <asm_macros.S>
 
-	.globl	console_init
-	.globl	console_uninit
-	.globl	console_putc
-	.globl	console_getc
-	.globl	console_flush
-
-	/*
-	 *  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 2
-	console_base: .word 0x0
-
-	/* -----------------------------------------------
-	 * int console_init(uintptr_t base_addr,
-	 * unsigned int uart_clk, unsigned int baud_rate)
-	 * Function to initialize the console without a
-	 * C Runtime to print debug information. It saves
-	 * the console base to the data section.
-	 * In: r0 - console base address
-	 *     r1 - Uart clock in Hz
-	 *     r2 - Baud rate
-	 * out: return 1 on success else 0 on error
-	 * Clobber list : r1 - r3
-	 * -----------------------------------------------
-	 */
-func console_init
-	/* Check the input base address */
-	cmp	r0, #0
-	beq	init_fail
-	ldr	r3, =console_base
-	str	r0, [r3]
-	b	console_core_init
-init_fail:
-	bx	lr
-endfunc console_init
-
-	/* -----------------------------------------------
-	 * void console_uninit(void)
-	 * Function to finish the use of console driver.
-	 * It sets the console_base as NULL so that any
-	 * further invocation of `console_putc` or
-	 * `console_getc` APIs would return error.
-	 * -----------------------------------------------
-	 */
-func console_uninit
-	mov	r0, #0
-	ldr	r3, =console_base
-	str	r0, [r3]
-	bx	lr
-endfunc console_uninit
-
-	/* ---------------------------------------------
-	 * 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 : r0 - character to be printed
-	 * Out : return -1 on error else return character.
-	 * Clobber list : r1, r2
-	 * ---------------------------------------------
-	 */
-func console_putc
-	ldr	r2, =console_base
-	ldr	r1, [r2]
-	b	console_core_putc
-endfunc console_putc
-
-	/* ---------------------------------------------
-	 * 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 : r0, r1
-	 * ---------------------------------------------
-	 */
-func console_getc
-	ldr	r1, =console_base
-	ldr	r0, [r1]
-	b	console_core_getc
-endfunc console_getc
-
-	/* ---------------------------------------------
-	 * int console_flush(void)
-	 * Function to force a write of all buffered
-	 * data that hasn't been output. It returns 0
-	 * upon successful completion, otherwise it
-	 * returns -1.
-	 * Clobber list : r0, r1
-	 * ---------------------------------------------
-	 */
-func console_flush
-	ldr	r1, =console_base
-	ldr	r0, [r1]
-	b	console_core_flush
-endfunc console_flush
+ #if MULTI_CONSOLE_API
+ #include "multi_console.S"
+ #else
+ #include "deprecated_console.S"
+ #endif

drivers/console/aarch32/deprecated_console.S

+/*
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <asm_macros.S>
+
+/*
+ * This is the common console core code for the deprecated single-console API.
+ * New platforms should set MULTI_CONSOLE_API=1 and not use this file.
+ */
+#warning "Using deprecated console implementation. Please migrate to MULTI_CONSOLE_API"
+
+	.globl	console_init
+	.globl	console_uninit
+	.globl	console_putc
+	.globl	console_getc
+	.globl	console_flush
+
+	/*
+	 *  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 2
+	console_base: .word 0x0
+
+	/* -----------------------------------------------
+	 * int console_init(uintptr_t base_addr,
+	 * unsigned int uart_clk, unsigned int baud_rate)
+	 * Function to initialize the console without a
+	 * C Runtime to print debug information. It saves
+	 * the console base to the data section.
+	 * In: r0 - console base address
+	 *     r1 - Uart clock in Hz
+	 *     r2 - Baud rate
+	 * out: return 1 on success else 0 on error
+	 * Clobber list : r1 - r3
+	 * -----------------------------------------------
+	 */
+func console_init
+	/* Check the input base address */
+	cmp	r0, #0
+	beq	init_fail
+	ldr	r3, =console_base
+	str	r0, [r3]
+	b	console_core_init
+init_fail:
+	bx	lr
+endfunc console_init
+
+	/* -----------------------------------------------
+	 * void console_uninit(void)
+	 * Function to finish the use of console driver.
+	 * It sets the console_base as NULL so that any
+	 * further invocation of `console_putc` or
+	 * `console_getc` APIs would return error.
+	 * -----------------------------------------------
+	 */
+func console_uninit
+	mov	r0, #0
+	ldr	r3, =console_base
+	str	r0, [r3]
+	bx	lr
+endfunc console_uninit
+
+	/* ---------------------------------------------
+	 * 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 : r0 - character to be printed
+	 * Out : return -1 on error else return character.
+	 * Clobber list : r1, r2
+	 * ---------------------------------------------
+	 */
+func console_putc
+	ldr	r2, =console_base
+	ldr	r1, [r2]
+	b	console_core_putc
+endfunc console_putc
+
+	/* ---------------------------------------------
+	 * 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 : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_getc
+	ldr	r1, =console_base
+	ldr	r0, [r1]
+	b	console_core_getc
+endfunc console_getc
+
+	/* ---------------------------------------------
+	 * int console_flush(void)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output. It returns 0
+	 * upon successful completion, otherwise it
+	 * returns -1.
+	 * Clobber list : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_flush
+	ldr	r1, =console_base
+	ldr	r0, [r1]
+	b	console_core_flush
+endfunc console_flush

drivers/console/aarch32/multi_console.S

+/*
+ * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <console.h>
+
+	.globl	console_register
+	.globl	console_unregister
+	.globl	console_is_registered
+	.globl	console_set_scope
+	.globl	console_switch_state
+	.globl	console_putc
+	.globl	console_getc
+	.globl	console_flush
+
+	/*
+	 *  The console list pointer 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_list ; .align 2
+	console_list: .word 0x0
+.section .data.console_state ; .align 0
+	console_state: .byte CONSOLE_FLAG_BOOT
+
+	/* -----------------------------------------------
+	 * int console_register(console_t *console)
+	 * Function to insert a new console structure into
+	 * the console list. Should usually be called by
+	 * console_<driver>_register implementations. The
+	 * data structure passed will be taken over by the
+	 * console framework and *MUST* be allocated in
+	 * persistent memory (e.g. the data section).
+	 * In : r0 - address of console_t structure
+	 * Out: r0 - Always 1 (for easier tail calling)
+	 * Clobber list: r0, r1
+	 * -----------------------------------------------
+	 */
+func console_register
+	push	{r6,  lr}
+#if ENABLE_ASSERTIONS
+	/* Assert that r0 isn't a NULL pointer */
+	cmp	r0, #0
+	ASM_ASSERT(ne)
+	/* Assert that the struct isn't in the stack */
+	ldr	r1, =__STACKS_START__
+	cmp	r0, r1
+	blo	not_on_stack
+	ldr	r1, =__STACKS_END__
+	cmp	r0, r1
+	ASM_ASSERT(hs)
+not_on_stack:
+	/* Assert that this struct isn't in the list */
+	mov	r1, r0 /* Preserve r0 and lr */
+	bl	console_is_registered
+	cmp	r0, #0
+	ASM_ASSERT(eq)
+	mov	r0, r1
+#endif /* ENABLE_ASSERTIONS */
+	ldr	r6, =console_list
+	ldr	r1, [r6]	/* R1 = first struct in list */
+	str	r0, [r6]	/* list head = new console */
+	str	r1, [r0, #CONSOLE_T_NEXT]	/* new console next ptr = R1 */
+	mov	r0, #1
+	pop	{r6, pc}
+endfunc console_register
+
+	/* -----------------------------------------------
+	 * int console_unregister(console_t *console)
+	 * Function to find a specific console in the list
+	 * of currently active consoles and remove it.
+	 * In: r0 - address of console_t struct to remove
+	 * Out: r0 - removed address, or NULL if not found
+	 * Clobber list: r0, r1
+	 * -----------------------------------------------
+	 */
+func console_unregister
+#if ENABLE_ASSERTIONS
+	/* Assert that r0 isn't a NULL pointer */
+	cmp	r0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	push	{r6}
+	ldr	r6, =console_list		/* R6 = ptr to first struct */
+	ldr	r1, [r6]			/* R1 = first struct */
+
+unregister_loop:
+	cmp	r1, #0
+	beq	unregister_not_found
+	cmp	r0, r1
+	beq	unregister_found
+	ldr	r6, [r6]			/* R6 = next ptr of struct */
+	ldr	r1, [r6]			/* R1 = next struct */
+	b	unregister_loop
+
+unregister_found:
+	ldr	r1, [r1]			/* R1 = next struct */
+	str	r1, [r6]			/* prev->next = cur->next */
+	pop	{r6}
+	bx	lr
+
+unregister_not_found:
+	mov	r0, #0				/* return NULL if not found */
+	pop	{r6}
+	bx	lr
+endfunc console_unregister
+
+	/* -----------------------------------------------
+	 * int console_is_registered(console_t *console)
+	 * Function to detect if a specific console is
+	 * registered or not.
+	 * In: r0 - address of console_t struct to remove
+	 * Out: r0 - 1 if it is registered, 0 if not.
+	 * Clobber list: r0
+	 * -----------------------------------------------
+	 */
+func console_is_registered
+#if ENABLE_ASSERTIONS
+	/* Assert that r0 isn't a NULL pointer */
+	cmp	r0, #0
+	ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+	push	{r6}
+	ldr	r6, =console_list
+	ldr	r6, [r6]	/* R6 = first console struct */
+check_registered_loop:
+	cmp	r6, #0			/* Check if end of list */
+	beq	console_not_registered
+	cmp	r0, r6		/* Check if the pointers are different */
+	beq	console_registered
+	ldr	r6, [r6, #CONSOLE_T_NEXT]	/* Get pointer to next struct */
+	b	check_registered_loop
+console_not_registered:
+	mov	r0, #0
+	pop	{r6}
+	bx	lr
+console_registered:
+	mov	r0, #1
+	pop	{r6}
+	bx	lr
+endfunc console_is_registered
+
+	/* -----------------------------------------------
+	 * void console_switch_state(unsigned int new_state)
+	 * Function to switch the current console state.
+	 * The console state determines which of the
+	 * registered consoles are actually used at a time.
+	 * In : r0 - global console state to move to
+	 * Clobber list: r0, r1
+	 * -----------------------------------------------
+	 */
+func console_switch_state
+	ldr	r1, =console_state
+	strb	r0, [r1]
+	bx	lr
+endfunc console_switch_state
+
+	/* -----------------------------------------------
+	 * void console_set_scope(console_t *console,
+	 *                       unsigned int scope)
+	 * Function to update the states that a given console
+	 * may be active in.
+	 * In : r0 - pointer to console_t struct
+	 *    : r1 - new active state mask
+	 * Clobber list: r0, r1, r2
+	 * -----------------------------------------------
+	 */
+func console_set_scope
+#if ENABLE_ASSERTIONS
+	ands	r2, r1, #~CONSOLE_FLAG_SCOPE_MASK
+	ASM_ASSERT(eq)
+#endif /* ENABLE_ASSERTIONS */
+	ldr	r2, [r0, #CONSOLE_T_FLAGS]
+	and	r2, r2, #~CONSOLE_FLAG_SCOPE_MASK
+	orr	r2, r2, r1
+	str	r2, [r0, #CONSOLE_T_FLAGS]
+	bx	lr
+endfunc console_set_scope
+
+	/* ---------------------------------------------
+	 * int console_putc(int c)
+	 * Function to output a character. Calls all
+	 * active console's putc() handlers in succession.
+	 * In : r0 - character to be printed
+	 * Out: r0 - printed character on success, or < 0
+	             if at least one console had an error
+	 * Clobber list : r0, r1, r2
+	 * ---------------------------------------------
+	 */
+func console_putc
+	push	{r4-r6, lr}
+	mov	r5, #ERROR_NO_VALID_CONSOLE	/* R5 = current return value */
+	mov	r4, r0				/* R4 = character to print */
+	ldr	r6, =console_list
+	ldr	r6, [r6]	/* R6 = first console struct */
+
+putc_loop:
+	cmp	r6, #0
+	beq	putc_done
+	ldr	r1, =console_state
+	ldrb	r1, [r1]
+	ldr	r2, [r6, #CONSOLE_T_FLAGS]
+	tst	r1, r2
+	beq	putc_continue
+	ldr	r2, [r6, #CONSOLE_T_PUTC]
+	cmp	r2, #0
+	beq	putc_continue
+	mov	r0, r4
+	mov	r1, r6
+	blx	r2
+	cmp	r5, #ERROR_NO_VALID_CONSOLE	/* update R5 if it's NOVALID */
+	cmpne	r0, #0				/* else update it if R0 < 0 */
+	movlt	r5, r0
+putc_continue:
+	ldr	r6, [r6]			/* R6 = next struct */
+	b	putc_loop
+
+putc_done:
+	mov	r0, r5
+	pop	{r4-r6, pc}
+endfunc console_putc
+
+	/* ---------------------------------------------
+	 * int console_getc(void)
+	 * Function to get a character from any console.
+	 * Keeps looping through all consoles' getc()
+	 * handlers until one of them returns a
+	 * character, then stops iterating and returns
+	 * that character to the caller. Will stop looping
+	 * if all active consoles report real errors
+	 * (other than just not having a char available).
+	 * Out : r0 - read character, or < 0 on error
+	 * Clobber list : r0, r1
+	 * ---------------------------------------------
+	 */
+func console_getc
+	push	{r5-r6, lr}
+getc_try_again:
+	mov	r5, #ERROR_NO_VALID_CONSOLE	/* R5 = current return value */
+	ldr	r6, =console_list
+	ldr	r6, [r6]			/* R6 = first console struct */
+	cmp	r6, #0
+	bne	getc_loop
+	mov	r0, r5				/* If no consoles registered */
+	pop	{r5-r6, pc}			/* return immediately. */
+
+getc_loop:
+	ldr	r0, =console_state
+	ldrb	r0, [r0]
+	ldr	r1, [r6, #CONSOLE_T_FLAGS]
+	tst	r0, r1
+	beq	getc_continue
+	ldr	r1, [r6, #CONSOLE_T_GETC]
+	cmp	r1, #0
+	beq	getc_continue
+	mov	r0, r6
+	blx	r1
+	cmp	r0, #0				/* if R0 >= 0: return */
+	bge	getc_found
+	cmp	r5, #ERROR_NO_PENDING_CHAR	/* may update R5 (NOCHAR has */
+	movne	r5, r0				/* precedence vs real errors) */
+getc_continue:
+	ldr	r6, [r6]			/* R6 = next struct */
+	cmp	r6, #0
+	bne	getc_loop
+	cmp	r5, #ERROR_NO_PENDING_CHAR	/* Keep scanning if at least */
+	beq	getc_try_again			/* one console returns NOCHAR */
+	mov	r0, r5
+
+getc_found:
+	pop	{r5-r6, pc}
+endfunc console_getc
+
+	/* ---------------------------------------------
+	 * int console_flush(void)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output. Calls all
+	 * console's flush() handlers in succession.
+	 * Out: r0 - 0 on success, < 0 if at least one error
+	 * Clobber list : r0, r1, r2
+	 * ---------------------------------------------
+	 */
+func console_flush
+	push	{r5-r6, lr}
+	mov	r5, #ERROR_NO_VALID_CONSOLE	/* R5 = current return value */
+	ldr	r6, =console_list
+	ldr	r6, [r6]			/* R6 = first console struct */
+
+flush_loop:
+	cmp	r6, #0
+	beq	flush_done
+	ldr	r1, =console_state
+	ldrb	r1, [r1]
+	ldr	r2, [r6, #CONSOLE_T_FLAGS]
+	tst	r1, r2
+	beq	flush_continue
+	ldr	r1, [r6, #CONSOLE_T_FLUSH]
+	cmp	r1, #0
+	beq	flush_continue
+	mov	r0, r6
+	blx	r1
+	cmp	r5, #ERROR_NO_VALID_CONSOLE	/* update R5 if it's NOVALID */
+	cmpne	r0, #0				/* else update it if R0 < 0 */
+	movlt	r5, r0
+flush_continue:
+	ldr	r6, [r6]			/* R6 = next struct */
+	b	flush_loop
+
+flush_done:
+	mov	r0, r5
+	pop	{r5-r6, pc}
+endfunc console_flush