36 lines
1002 B
C
36 lines
1002 B
C
#include "pico.h"
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#include "pico/time.h"
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#include "pico/bootrom.h"
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// Allow user override of the LED mask
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#ifndef USB_BOOT_LED_ACTIVITY_MASK
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#define USB_BOOT_LED_ACTIVITY_MASK 0
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#endif
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// Doesn't make any sense for a RAM only binary
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#if !PICO_NO_FLASH
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static const uint32_t magic_token[] = {
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0xf01681de, 0xbd729b29, 0xd359be7a,
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};
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static uint32_t __uninitialized_ram(magic_location)[count_of(magic_token)];
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// run at initialization time
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static void __attribute__((constructor)) boot_double_tap_check() {
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for (uint i = 0; i < count_of(magic_token); i++) {
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if (magic_location[i] != magic_token[i]) {
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// Arm for 100 ms then disarm and continue booting
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for (i = 0; i < count_of(magic_token); i++) {
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magic_location[i] = magic_token[i];
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}
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busy_wait_us(100000);
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magic_location[0] = 0;
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return;
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}
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}
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magic_location[0] = 0;
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reset_usb_boot(USB_BOOT_LED_ACTIVITY_MASK, 0);
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}
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#endif |