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Make a couple of demos build using picolibc (FreeRTOS#1202)
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* [RISC-V-Qemu-virt_GCC Demo] Add picolibc support

Add minimal picolibc support:

 * Use --specs=picolibc.specs to direct gcc at picolibc
 * Use -DPICOLIBC_INTEGER_PRINTF_SCANF to enable smaller printf implementation
 * Enable configUSE_PICOLIBC_TLS for thread local storage
 * Add TLS section to linker script

Signed-off-by: Keith Packard <[email protected]>

* [CORTEX_MPU_M3_MPS2_QEMU_GCC Demo] Add picolibc support

Add minimal picolibc support to this demo

 * Use --specs=picolibc.specs to direct gcc at picolibc
 * Use -DPICOLIBC_INTEGER_PRINTF_SCANF to enable smaller printf implementation
 * Enable configUSE_PICOLIBC_TLS for thread local storage
 * Add TLS section to linker script
 * Replace newlib syscall hooks with picolibc ones

Signed-off-by: Keith Packard <[email protected]>

---------

Signed-off-by: Keith Packard <[email protected]>
Co-authored-by: Keith Packard <[email protected]>
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keith-packard and Keith Packard authored Apr 3, 2024
1 parent 7514cd3 commit eb97c5d
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Showing 7 changed files with 89 additions and 2 deletions.
4 changes: 4 additions & 0 deletions FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/FreeRTOSConfig.h
Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,10 @@ extern void vAssertCalled( void );
#define configASSERT( x ) if( ( x ) == 0 ) vAssertCalled()
#define configQUEUE_REGISTRY_SIZE 20

#ifdef PICOLIBC_TLS
#define configUSE_PICOLIBC_TLS 1
#endif

#define configUSE_PREEMPTION 1
#define configUSE_TIME_SLICING 0
#define configUSE_PORT_OPTIMISED_TASK_SELECTION 0
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5 changes: 5 additions & 0 deletions FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,11 @@ else
CFLAGS += -O3
endif

ifeq ($(PICOLIBC), 1)
CFLAGS += --specs=picolibc.specs -DPICOLIBC_INTEGER_PRINTF_SCANF
LDFLAGS += --specs=picolibc.specs -DPICOLIBC_INTEGER_PRINTF_SCANF
endif

OBJ_FILES := $(SOURCE_FILES:%.c=$(BUILD_DIR)/%.o)

.PHONY: clean
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22 changes: 22 additions & 0 deletions FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/scripts/mps2_m3.ld
Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,26 @@ SECTIONS
_edata = .;
} > RAM AT > FLASH

.tdata : {
*(.tdata .tdata.*)
} >FLASH

.tbss (NOLOAD) : {
*(.tbss .tbss.* .gnu.linkonce.tb.*)
*(.tcommon)
PROVIDE( __tbss_end = . );
PROVIDE( __tls_end = . );
} >FLASH
PROVIDE( __tdata_source = LOADADDR(.tdata) );
PROVIDE( __tdata_source_end = LOADADDR(.tdata) + SIZEOF(.tdata) );
PROVIDE( __tdata_size = SIZEOF(.tdata) );
PROVIDE( __tbss_offset = ADDR(.tbss) - ADDR(.tdata) );
PROVIDE( __tbss_start = ADDR(.tbss) );
PROVIDE( __tbss_size = SIZEOF(.tbss) );
PROVIDE( __tls_size = __tls_end - ADDR(.tdata) );
PROVIDE( __tls_align = MAX(ALIGNOF(.tdata), ALIGNOF(.tbss)) );
PROVIDE( __arm32_tls_tcb_offset = MAX(8, __tls_align) );
PROVIDE( __arm64_tls_tcb_offset = MAX(16, __tls_align) );

. = ALIGN(4);
.bss :
Expand All @@ -195,8 +215,10 @@ SECTIONS
PROVIDE ( end = . );
PROVIDE ( _end = . );
_heap_bottom = .;
__heap_start = .;
. = . + _Min_Heap_Size;
_heap_top = .;
__heap_end = .;
. = . + _Min_Stack_Size;
. = ALIGN(8);
} >RAM
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32 changes: 30 additions & 2 deletions FreeRTOS/Demo/CORTEX_MPU_M3_MPS2_QEMU_GCC/syscall.c
Original file line number Diff line number Diff line change
Expand Up @@ -50,8 +50,6 @@ extern unsigned long _heap_bottom;
extern unsigned long _heap_top;
extern unsigned long g_ulBase;

static void * heap_end = 0;

/**
* @brief initializes the UART emulated hardware
*/
Expand All @@ -61,6 +59,34 @@ void uart_init()
UART0_ADDR->CTRL = UART_CTRL_TX_EN;
}

#ifdef __PICOLIBC__

#include <stdio.h>

/**
* @brief Write byte to the UART channel to be displayed on the command line
* with qemu
* @param [in] c byte to send
* @param [in] file ignored
* @returns the character written (cast to unsigned so it is not an error value)
*/

int
_uart_putc(char c, FILE *file)
{
(void) file;
UART_DR( UART0_ADDR ) = c;
return (unsigned char) c;
}

static FILE __stdio = FDEV_SETUP_STREAM(_uart_putc, NULL, NULL, _FDEV_SETUP_WRITE);

FILE *const stdout = &__stdio;

#else

static void * heap_end = 0;

/**
* @brief not used anywhere in the code
* @todo implement if necessary
Expand Down Expand Up @@ -181,6 +207,8 @@ int _getpid()
return 1;
}

#endif

#ifdef __cplusplus
}
#endif
4 changes: 4 additions & 0 deletions FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/FreeRTOSConfig.h
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,10 @@
#define configMTIME_BASE_ADDRESS ( CLINT_ADDR + CLINT_MTIME )
#define configMTIMECMP_BASE_ADDRESS ( CLINT_ADDR + CLINT_MTIMECMP )

#ifdef PICOLIBC_TLS
#define configUSE_PICOLIBC_TLS 1
#endif

#define configUSE_PREEMPTION 1
#define configUSE_IDLE_HOOK 0
#define configUSE_TICK_HOOK 1
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5 changes: 5 additions & 0 deletions FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,11 @@ else
CFLAGS += -O2
endif

ifeq ($(PICOLIBC), 1)
CFLAGS += --specs=picolibc.specs -DPICOLIBC_INTEGER_PRINTF_SCANF
LDFLAGS += --specs=picolibc.specs -DPICOLIBC_INTEGER_PRINTF_SCANF
endif

SRCS = main.c main_blinky.c riscv-virt.c ns16550.c \
$(DEMO_SOURCE_DIR)/EventGroupsDemo.c \
$(DEMO_SOURCE_DIR)/TaskNotify.c \
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19 changes: 19 additions & 0 deletions FreeRTOS/Demo/RISC-V-Qemu-virt_GCC/fake_rom.lds
Original file line number Diff line number Diff line change
Expand Up @@ -81,6 +81,25 @@ SECTIONS
_edata = .;
} >ram AT>rom

.tdata : {
*(.tdata .tdata.*)
} >rom AT>rom

.tbss (NOLOAD) : {
*(.tbss .tbss.* .gnu.linkonce.tb.*)
*(.tcommon)
PROVIDE( __tbss_end = . );
PROVIDE( __tls_end = . );
} >rom AT>rom
PROVIDE( __tdata_source = LOADADDR(.tdata) );
PROVIDE( __tdata_source_end = LOADADDR(.tdata) + SIZEOF(.tdata) );
PROVIDE( __tdata_size = SIZEOF(.tdata) );
PROVIDE( __tbss_offset = ADDR(.tbss) - ADDR(.tdata) );
PROVIDE( __tbss_start = ADDR(.tbss) );
PROVIDE( __tbss_size = SIZEOF(.tbss) );
PROVIDE( __tls_size = __tls_end - ADDR(.tdata) );
PROVIDE( __tls_align = MAX(ALIGNOF(.tdata), ALIGNOF(.tbss)) );

.bss.align :
{
. = ALIGN(4);
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