This includes empty stubs for most core Arduino functions.
Need to actually implement all those digital reads writes whatever.
Need to prebuild toolchains (xtensa-elf-lx106) for 3 platforms and put them on some download server.
Need to do the same with esptool.
Need to fix 0x40000 binary generation and add correct upload commands.
Maybe even implement uploads over WiFi.
Previously, when verbose uploads were enabled, avrdude was run with four
-v options, causing it to dump all raw bytes exchanged with the
bootloader. This floods the console so much that meaningful output
mostly disappears.
Most users probably want to enable verbose mode just to see what avrdude
command is ran. Furthermore, users that benefit from the raw bytes
dumped are perfectly capable of either running avrdude manually, or
modifying platform.txt. Given that, running avrdude with just one -v
should be plenty.
This fixes#891.
When checking the `left` argument, it previously allowed having
left == len. However, this means the substring starts one past the last
character in the string and should return the empty string. In practice,
this already worked correctly, because buffer[len] contains the trailing
nul, so it would (re)assign the empty string to `out`.
However, fixing this check makes it a bit more logical, and prevents a
fairly unlikely out-of-buffer write (to address 0x0) when calling
substring on an invalidated String:
String bar = (char*)NULL;
bar.substring(0, 0);
Previously, this method calculated the length of the string from the
given index onwards. However, the other remove() method called already
contains code for this calculation, which is used when the count passed
in is too big. This means we can just pass in a very big count that is
guaranteed to point past the end of the string, shrinking the remove
method by a few bytes.
Previously, if you passed in a very big index and/or count, the
`index + count` could overflow, making the count be used as-is instead
of being truncated (causing the string to be updated wrongly and
potentially writing to arbitrary memory locations).
We can rewrite the comparison to use `len - index` instead. Since we
know that index < len, we are sure this subtraction does not overflow,
regardless of what values of index and count we pass in.
As an added bonus, the `len - index` value already needed be calculated
inside the if, so this saves a few instructions in the generated code.
To illustrate this problem, consider this code:
String foo = "foo";
Serial.println(foo.length()); // Prints 3
foo.remove(1, 65535); // Should remove all but first character
Serial.println(foo.length()); // Prints 4 without this patch
Not shown in this is example is that some arbitrary memory is written
as well.
The following empty stubs has been replaced by the gcc
flag -fno-threadsafe-static:
int __cxa_guard_acquire(__guard *);
void __cxa_guard_release (__guard *);
void __cxa_guard_abort (__guard *);
The following empty stubs has been moved into their specific
module abi.cpp:
void __cxa_pure_virtual(void) __attribute ((noreturn));
void __cxa_deleted_virtual(void) __attribute ((noreturn));
Fix#107
