VideoCore IV port

ports/vc4/Makefile

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+include ../../py/mkenv.mk
+
+CROSS = 1
+
+# qstr definitions (must come before including py.mk)
+QSTR_DEFS = qstrdefsport.h
+
+# include py core make definitions
+include $(TOP)/py/py.mk
+
+ifeq ($(CROSS), 1)
+CROSS_COMPILE = vc4-elf-
+endif
+
+INC += -I.
+INC += -I$(TOP)
+INC += -I$(BUILD)
+
+ifeq ($(CROSS), 1)
+CFLAGS = $(INC) -Wall -Werror -std=c99 -nostdlib $(COPT)
+LD=vc4-elf-gcc
+LDFLAGS = -T vc4-teststub.ld -Wl,-Map=$@.map -Wl,--cref -lm
+else
+LD = gcc
+CFLAGS = -m32 $(INC) -Wall -Werror -std=c99 $(COPT)
+LDFLAGS = -m32 -Wl,-Map=$@.map,--cref -Wl,--gc-sections
+endif
+
+# Tune for Debugging or Optimization
+ifeq ($(DEBUG), 1)
+CFLAGS += -O0 -ggdb
+else
+CFLAGS += -Os -DNDEBUG
+CFLAGS += -fdata-sections -ffunction-sections
+endif
+
+LIBS =
+
+SRC_C = \
+ main.c \
+ uart_core.c \
+ lib/utils/printf.c \
+ lib/utils/stdout_helpers.c \
+ lib/utils/pyexec.c \
+ lib/libc/string0.c \
+ lib/mp-readline/readline.c \
+ $(BUILD)/_frozen_mpy.c \
+
+OBJ = $(PY_CORE_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
+
+all: $(BUILD)/firmware.bin
+
+$(BUILD)/_frozen_mpy.c: frozentest.mpy $(BUILD)/genhdr/qstrdefs.generated.h
+ $(ECHO) "MISC freezing bytecode"
+ $(Q)$(TOP)/tools/mpy-tool.py -f -q $(BUILD)/genhdr/qstrdefs.preprocessed.h -mlongint-impl=none $< > $@
+
+$(BUILD)/firmware.elf: $(OBJ)
+ $(ECHO) "LINK $@"
+ $(Q)$(LD) $(LDFLAGS) -o $@ $^ $(LIBS)
+ $(Q)$(SIZE) $@
+
+$(BUILD)/firmware.bin: $(BUILD)/firmware.elf
+ $(Q)$(OBJCOPY) -O binary $^ $(BUILD)/firmware.bin
+
+include $(TOP)/py/mkrules.mk

ports/vc4/README.md

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+# VC4 port
+
+This port is intended to run on the Broadcom VideoCore IV VPU.
+
+## Building 
+
+Use the VideoCore IV GNU toolchain at https://github.com/itszor/vc4-toolchain 
+

ports/vc4/frozentest.py

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+print('uPy')
+print('a long string that is not interned')
+print('a string that has unicode αβγ chars')
+print(b'bytes 1234\x01')
+print(123456789)
+for i in range(4):
+ print(i)

ports/vc4/main.c

@@ -0,0 +1,258 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "py/compile.h"
+#include "py/runtime.h"
+#include "py/repl.h"
+#include "py/gc.h"
+#include "py/mperrno.h"
+#include "lib/utils/pyexec.h"
+
+#if MICROPY_ENABLE_COMPILER
+void do_str(const char *src, mp_parse_input_kind_t input_kind) {
+ nlr_buf_t nlr;
+ if (nlr_push(&nlr) == 0) {
+ mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
+ qstr source_name = lex->source_name;
+ mp_parse_tree_t parse_tree = mp_parse(lex, input_kind);
+ mp_obj_t module_fun = mp_compile(&parse_tree, source_name, MP_EMIT_OPT_NONE, true);
+ mp_call_function_0(module_fun);
+ nlr_pop();
+ } else {
+ // uncaught exception
+ mp_obj_print_exception(&mp_plat_print, (mp_obj_t)nlr.ret_val);
+ }
+}
+#endif
+
+static char *stack_top;
+#if MICROPY_ENABLE_GC
+static char heap[2048];
+#endif
+
+int main(int argc, char **argv) {
+ int stack_dummy;
+ stack_top = (char*)&stack_dummy;
+
+ #if MICROPY_ENABLE_GC
+ gc_init(heap, heap + sizeof(heap));
+ #endif
+ mp_init();
+ #if MICROPY_ENABLE_COMPILER
+ #if MICROPY_REPL_EVENT_DRIVEN
+ pyexec_event_repl_init();
+ for (;;) {
+ int c = mp_hal_stdin_rx_chr();
+ if (pyexec_event_repl_process_char(c)) {
+ break;
+ }
+ }
+ #else
+ pyexec_friendly_repl();
+ #endif
+ //do_str("print('hello world!', list(x+1 for x in range(10)), end='eol\\n')", MP_PARSE_SINGLE_INPUT);
+ //do_str("for i in range(10):\r\n print(i)", MP_PARSE_FILE_INPUT);
+ #else
+ pyexec_frozen_module("frozentest.py");
+ #endif
+ mp_deinit();
+ return 0;
+}
+
+void gc_collect(void) {
+ // WARNING: This gc_collect implementation doesn't try to get root
+ // pointers from CPU registers, and thus may function incorrectly.
+ void *dummy;
+ gc_collect_start();
+ gc_collect_root(&dummy, ((mp_uint_t)stack_top - (mp_uint_t)&dummy) / sizeof(mp_uint_t));
+ gc_collect_end();
+ gc_dump_info();
+}
+
+mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
+ mp_raise_OSError(MP_ENOENT);
+}
+
+mp_import_stat_t mp_import_stat(const char *path) {
+ return MP_IMPORT_STAT_NO_EXIST;
+}
+
+mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+ return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
+
+void nlr_jump_fail(void *val) {
+ while (1);
+}
+
+void NORETURN __fatal_error(const char *msg) {
+ while (1);
+}
+
+#ifndef NDEBUG
+void MP_WEAK __assert_func(const char *file, int line, const char *func, const char *expr) {
+ printf("Assertion '%s' failed, at file %s:%d\n", expr, file, line);
+ __fatal_error("Assertion failed");
+}
+#endif
+
+#if MICROPY_MIN_USE_CORTEX_CPU
+
+// this is a minimal IRQ and reset framework for any Cortex-M CPU
+
+extern uint32_t _estack, _sidata, _sdata, _edata, _sbss, _ebss;
+
+void Reset_Handler(void) __attribute__((naked));
+void Reset_Handler(void) {
+ // set stack pointer
+ __asm volatile ("ldr sp, =_estack");
+ // copy .data section from flash to RAM
+ for (uint32_t *src = &_sidata, *dest = &_sdata; dest < &_edata;) {
+ *dest++ = *src++;
+ }
+ // zero out .bss section
+ for (uint32_t *dest = &_sbss; dest < &_ebss;) {
+ *dest++ = 0;
+ }
+ // jump to board initialisation
+ void _start(void);
+ _start();
+}
+
+void Default_Handler(void) {
+ for (;;) {
+ }
+}
+
+const uint32_t isr_vector[] __attribute__((section(".isr_vector"))) = {
+ (uint32_t)&_estack,
+ (uint32_t)&Reset_Handler,
+ (uint32_t)&Default_Handler, // NMI_Handler
+ (uint32_t)&Default_Handler, // HardFault_Handler
+ (uint32_t)&Default_Handler, // MemManage_Handler
+ (uint32_t)&Default_Handler, // BusFault_Handler
+ (uint32_t)&Default_Handler, // UsageFault_Handler
+ 0,
+ 0,
+ 0,
+ 0,
+ (uint32_t)&Default_Handler, // SVC_Handler
+ (uint32_t)&Default_Handler, // DebugMon_Handler
+ 0,
+ (uint32_t)&Default_Handler, // PendSV_Handler
+ (uint32_t)&Default_Handler, // SysTick_Handler
+};
+
+void _start(void) {
+ // when we get here: stack is initialised, bss is clear, data is copied
+
+ // SCB->CCR: enable 8-byte stack alignment for IRQ handlers, in accord with EABI
+ *((volatile uint32_t*)0xe000ed14) |= 1 << 9;
+
+ // initialise the cpu and peripherals
+ #if MICROPY_MIN_USE_STM32_MCU
+ void stm32_init(void);
+ stm32_init();
+ #endif
+
+ // now that we have a basic system up and running we can call main
+ main(0, NULL);
+
+ // we must not return
+ for (;;) {
+ }
+}
+
+#endif
+
+#if MICROPY_MIN_USE_STM32_MCU
+
+// this is minimal set-up code for an STM32 MCU
+
+typedef struct {
+ volatile uint32_t CR;
+ volatile uint32_t PLLCFGR;
+ volatile uint32_t CFGR;
+ volatile uint32_t CIR;
+ uint32_t _1[8];
+ volatile uint32_t AHB1ENR;
+ volatile uint32_t AHB2ENR;
+ volatile uint32_t AHB3ENR;
+ uint32_t _2;
+ volatile uint32_t APB1ENR;
+ volatile uint32_t APB2ENR;
+} periph_rcc_t;
+
+typedef struct {
+ volatile uint32_t MODER;
+ volatile uint32_t OTYPER;
+ volatile uint32_t OSPEEDR;
+ volatile uint32_t PUPDR;
+ volatile uint32_t IDR;
+ volatile uint32_t ODR;
+ volatile uint16_t BSRRL;
+ volatile uint16_t BSRRH;
+ volatile uint32_t LCKR;
+ volatile uint32_t AFR[2];
+} periph_gpio_t;
+
+typedef struct {
+ volatile uint32_t SR;
+ volatile uint32_t DR;
+ volatile uint32_t BRR;
+ volatile uint32_t CR1;
+} periph_uart_t;
+
+#define USART1 ((periph_uart_t*) 0x40011000)
+#define GPIOA ((periph_gpio_t*) 0x40020000)
+#define GPIOB ((periph_gpio_t*) 0x40020400)
+#define RCC ((periph_rcc_t*) 0x40023800)
+
+// simple GPIO interface
+#define GPIO_MODE_IN (0)
+#define GPIO_MODE_OUT (1)
+#define GPIO_MODE_ALT (2)
+#define GPIO_PULL_NONE (0)
+#define GPIO_PULL_UP (0)
+#define GPIO_PULL_DOWN (1)
+void gpio_init(periph_gpio_t *gpio, int pin, int mode, int pull, int alt) {
+ gpio->MODER = (gpio->MODER & ~(3 << (2 * pin))) | (mode << (2 * pin));
+ // OTYPER is left as default push-pull
+ // OSPEEDR is left as default low speed
+ gpio->PUPDR = (gpio->PUPDR & ~(3 << (2 * pin))) | (pull << (2 * pin));
+ gpio->AFR[pin >> 3] = (gpio->AFR[pin >> 3] & ~(15 << (4 * (pin & 7)))) | (alt << (4 * (pin & 7)));
+}
+#define gpio_get(gpio, pin) ((gpio->IDR >> (pin)) & 1)
+#define gpio_set(gpio, pin, value) do { gpio->ODR = (gpio->ODR & ~(1 << (pin))) | (value << pin); } while (0)
+#define gpio_low(gpio, pin) do { gpio->BSRRH = (1 << (pin)); } while (0)
+#define gpio_high(gpio, pin) do { gpio->BSRRL = (1 << (pin)); } while (0)
+
+void stm32_init(void) {
+ // basic MCU config
+ RCC->CR |= (uint32_t)0x00000001; // set HSION
+ RCC->CFGR = 0x00000000; // reset all
+ RCC->CR &= (uint32_t)0xfef6ffff; // reset HSEON, CSSON, PLLON
+ RCC->PLLCFGR = 0x24003010; // reset PLLCFGR
+ RCC->CR &= (uint32_t)0xfffbffff; // reset HSEBYP
+ RCC->CIR = 0x00000000; // disable IRQs
+
+ // leave the clock as-is (internal 16MHz)
+
+ // enable GPIO clocks
+ RCC->AHB1ENR |= 0x00000003; // GPIOAEN, GPIOBEN
+
+ // turn on an LED! (on pyboard it's the red one)
+ gpio_init(GPIOA, 13, GPIO_MODE_OUT, GPIO_PULL_NONE, 0);
+ gpio_high(GPIOA, 13);
+
+ // enable UART1 at 9600 baud (TX=B6, RX=B7)
+ gpio_init(GPIOB, 6, GPIO_MODE_ALT, GPIO_PULL_NONE, 7);
+ gpio_init(GPIOB, 7, GPIO_MODE_ALT, GPIO_PULL_NONE, 7);
+ RCC->APB2ENR |= 0x00000010; // USART1EN
+ USART1->BRR = (104 << 4) | 3; // 16MHz/(16*104.1875) = 9598 baud
+ USART1->CR1 = 0x0000200c; // USART enable, tx enable, rx enable
+}
+
+#endif