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| 1 | +#include <stdint.h> |
| 2 | +#include <stdbool.h> |
| 3 | + |
| 4 | + |
| 5 | +// a pointer to this is a null pointer, but the compiler does not |
| 6 | +// know that because "sram" is a linker symbol from sections.lds. |
| 7 | +extern uint32_t sram; |
| 8 | + |
| 9 | +#define reg_spictrl (*(volatile uint32_t*)0x02000000) |
| 10 | +#define reg_uart_clkdiv (*(volatile uint32_t*)0x02000004) |
| 11 | +#define reg_uart_data (*(volatile uint32_t*)0x02000008) |
| 12 | +#define reg_leds (*(volatile uint32_t*)0x03000000) |
| 13 | +#define reg_btns (*(volatile uint32_t*)0x03000004) |
| 14 | + |
| 15 | + |
| 16 | +// -------------------------------------------------------- |
| 17 | + |
| 18 | +void putchar(char c) |
| 19 | +{ |
| 20 | + if (c == '\n') |
| 21 | + putchar('\r'); |
| 22 | + reg_uart_data = c; |
| 23 | +} |
| 24 | + |
| 25 | +void print(const char *p) |
| 26 | +{ |
| 27 | + while (*p) |
| 28 | + putchar(*(p++)); |
| 29 | +} |
| 30 | + |
| 31 | +void print_hex(uint32_t v, int digits) |
| 32 | +{ |
| 33 | + for (int i = 7; i >= 0; i--) { |
| 34 | + char c = "0123456789abcdef"[(v >> (4*i)) & 15]; |
| 35 | + if (c == '0' && i >= digits) continue; |
| 36 | + putchar(c); |
| 37 | + digits = i; |
| 38 | + } |
| 39 | +} |
| 40 | + |
| 41 | +void print_dec(uint32_t v) |
| 42 | +{ |
| 43 | + if (v >= 1000) { |
| 44 | + print(">=1000"); |
| 45 | + return; |
| 46 | + } |
| 47 | + |
| 48 | + if (v >= 900) { putchar('9'); v -= 900; } |
| 49 | + else if (v >= 800) { putchar('8'); v -= 800; } |
| 50 | + else if (v >= 700) { putchar('7'); v -= 700; } |
| 51 | + else if (v >= 600) { putchar('6'); v -= 600; } |
| 52 | + else if (v >= 500) { putchar('5'); v -= 500; } |
| 53 | + else if (v >= 400) { putchar('4'); v -= 400; } |
| 54 | + else if (v >= 300) { putchar('3'); v -= 300; } |
| 55 | + else if (v >= 200) { putchar('2'); v -= 200; } |
| 56 | + else if (v >= 100) { putchar('1'); v -= 100; } |
| 57 | + |
| 58 | + if (v >= 90) { putchar('9'); v -= 90; } |
| 59 | + else if (v >= 80) { putchar('8'); v -= 80; } |
| 60 | + else if (v >= 70) { putchar('7'); v -= 70; } |
| 61 | + else if (v >= 60) { putchar('6'); v -= 60; } |
| 62 | + else if (v >= 50) { putchar('5'); v -= 50; } |
| 63 | + else if (v >= 40) { putchar('4'); v -= 40; } |
| 64 | + else if (v >= 30) { putchar('3'); v -= 30; } |
| 65 | + else if (v >= 20) { putchar('2'); v -= 20; } |
| 66 | + else if (v >= 10) { putchar('1'); v -= 10; } |
| 67 | + |
| 68 | + if (v >= 9) { putchar('9'); v -= 9; } |
| 69 | + else if (v >= 8) { putchar('8'); v -= 8; } |
| 70 | + else if (v >= 7) { putchar('7'); v -= 7; } |
| 71 | + else if (v >= 6) { putchar('6'); v -= 6; } |
| 72 | + else if (v >= 5) { putchar('5'); v -= 5; } |
| 73 | + else if (v >= 4) { putchar('4'); v -= 4; } |
| 74 | + else if (v >= 3) { putchar('3'); v -= 3; } |
| 75 | + else if (v >= 2) { putchar('2'); v -= 2; } |
| 76 | + else if (v >= 1) { putchar('1'); v -= 1; } |
| 77 | + else putchar('0'); |
| 78 | +} |
| 79 | + |
| 80 | +char getchar_prompt(char *prompt) |
| 81 | +{ |
| 82 | + int32_t c = -1; |
| 83 | + |
| 84 | + uint32_t cycles_begin, cycles_now, cycles; |
| 85 | + __asm__ volatile ("rdcycle %0" : "=r"(cycles_begin)); |
| 86 | + |
| 87 | + reg_leds = ~0; |
| 88 | + |
| 89 | + if (prompt) |
| 90 | + print(prompt); |
| 91 | + |
| 92 | + while (c == -1) { |
| 93 | + __asm__ volatile ("rdcycle %0" : "=r"(cycles_now)); |
| 94 | + cycles = cycles_now - cycles_begin; |
| 95 | + if (cycles > 12000000) { |
| 96 | + if (prompt) |
| 97 | + print(prompt); |
| 98 | + cycles_begin = cycles_now; |
| 99 | + reg_leds = ~reg_leds; |
| 100 | + } |
| 101 | + c = reg_uart_data; |
| 102 | + } |
| 103 | + |
| 104 | + reg_leds = 0; |
| 105 | + return c; |
| 106 | +} |
| 107 | + |
| 108 | +char getchar() |
| 109 | +{ |
| 110 | + return getchar_prompt(0); |
| 111 | +} |
| 112 | + |
| 113 | +static void delay_ms(uint16_t delayms) |
| 114 | +{ |
| 115 | + uint32_t N = 25*delayms; |
| 116 | + for (uint32_t i = 0; i < N; i++) { |
| 117 | + // do nothing |
| 118 | + } |
| 119 | +} |
| 120 | + |
| 121 | + |
| 122 | +void test_leds() |
| 123 | +{ |
| 124 | + print("testing LEDs...\n\n"); |
| 125 | + |
| 126 | + reg_leds = 0xff; |
| 127 | + |
| 128 | + for(uint8_t i = 0; i < 10; i++) { |
| 129 | + reg_leds = 0x0; |
| 130 | + delay_ms(1000); |
| 131 | + reg_leds = 0x2 ; |
| 132 | + delay_ms(1000); |
| 133 | + } |
| 134 | +} |
| 135 | + |
| 136 | +uint32_t set_irq_mask(uint32_t mask); asm ( |
| 137 | + ".global set_irq_mask\n" |
| 138 | + "set_irq_mask:\n" |
| 139 | + ".word 0x0605650b\n" |
| 140 | + "ret\n" |
| 141 | +); |
| 142 | + |
| 143 | +//void irq_handler(uint32_t irqs, uint32_t *regs) |
| 144 | +uint32_t* irq_handler(uint32_t irqs, uint32_t *regs) |
| 145 | +//uint32_t *irq(uint32_t *regs, uint32_t irqs) |
| 146 | +//uint32_t* irq(uint32_t irqs, uint32_t* regs) |
| 147 | +{ |
| 148 | + if ((irqs & (1<<5)) != 0) { |
| 149 | + print("i\n"); |
| 150 | + //reg_leds ^= 0x01; |
| 151 | + } |
| 152 | + |
| 153 | + return regs; |
| 154 | +} |
| 155 | + |
| 156 | +void main() { |
| 157 | + // test with UART 115200 8N1 |
| 158 | + reg_uart_clkdiv = 104; |
| 159 | + |
| 160 | + set_irq_mask(0x00); |
| 161 | + |
| 162 | + print("\n"); |
| 163 | + print(" ____ _ ____ ____\n"); |
| 164 | + print(" | _ \\(_) ___ ___/ ___| ___ / ___|\n"); |
| 165 | + print(" | |_) | |/ __/ _ \\___ \\ / _ \\| |\n"); |
| 166 | + print(" | __/| | (_| (_) |__) | (_) | |___\n"); |
| 167 | + print(" |_| |_|\\___\\___/____/ \\___/ \\____|\n"); |
| 168 | + |
| 169 | + // blink the user LED |
| 170 | + uint32_t led_timer = 0; |
| 171 | + |
| 172 | + while (1) { |
| 173 | + reg_leds = led_timer >> 16; |
| 174 | + led_timer = led_timer + 1; |
| 175 | + } |
| 176 | +} |
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