Bootloader初始化编译器以从闪存中的特定区域怎么开始运行

你看过Microchip现有的Bootloader项目吗？为此需要自定义链接器文件。



      以下为原文

    Have you looked at existing Bootloader projects by Microchip?
You need custom linker files for this

链接器方法很简单：在我的引导加载程序中，IVT是由程序控制的，发生的是BL被地址属性放置在IVT之后的页面上。为了防止IVT和页结束之间的空间使用一个const数组。因为在Bootloader中不使用中断，所以没有问题。-复位向量总是被改变为指向引导加载程序。然后引导加载程序在需要的地址（例如0x4000）下检查是否存在应用程序重置向量。如果不存在，则无限期地等待新的HEX下载，如果存在，则重置BL所使用的所有数据并跳转到应用程序重置向量。应用程序启动例程将删除剩余的剩余部分以使编译器不使用内存，最好的方法是告诉内存不在那里，最好是通过链接器脚本完成。您从项目中获取.gLD文件并创建它的副本。在新文件中，您必须找到一个包含“程序（XR）”的行，并将其更改为示例文件。将其添加到链接器文件FLDR.COMPILL上的项目上。这只是一种方式，如果您想在内存中间留一个孔，则可能创建多个部分。例如，我不知道…



      以下为原文

    The linker method made simple:
 
-in my bootloader the IVT is controlled by the program, what happens is that the BL is placed on the page after the IVT by the address attribute. to prevent the space between IVT and end of page from using an array of const is placed there. Since i don't use interrupts in the bootloader, no problems there.
-the reset vector is always changed to be pointing at the bootloader. then the bootloader checks at the required address (for example 0x4000) if the application reset vector is present.
-if not present, wait indefinetly for a new hex to download
-if present, reset all data used by the BL and jump to the application reset vector. app startup routine will delete the rest of leftovers
 
to make it so that the compiler doesn't use the memory, the best way is to tell it that the memory isn't there, and that's best accomplished by the linker script.
 
you take the .gld file from your project and create a copy of it. in the new file you will have to find a line containing "program(xr)" and change it
for example
/* Original:
program (xr)   : ORIGIN = 0x200,         LENGTH = 0x2A980
 Modified: */
program (xr)   : ORIGIN = 0x4000,        LENGTH = 0x26B80
save the file.
add it on your project on the linker file folder.
compile.
 
this is just one way to do it, it's probably possible to create multiple sections if you want to leave a hole in the middle of memory for example, i don't know..

Bootloader通常用两个独立的项目来完成，其中两个独立的非重叠链接器脚本，而在项目中作为一个特殊的功能来做它将在理论上是可能的，它会带来一些挑战。该功能需要在全Flash页面上。有一个引导加载应用程序注释，MCC有Bootloader支持。



      以下为原文

    A Bootloader is normally Done as two separate projects with two separate non overlapping Linker scripts.
While doing it as a special function in the project would be theoretically possible, it would present several challenges.
Number one would be you could not use any shared C libraries
2. The function would need to be on full flash pages.
 
There is a Bootloader app Note, and MCC has bootloader support.

事实上，当Flash被擦除的时候，我也不确定调试器会完美地工作，甚至在其他领域…



      以下为原文

    I am actually not "sure-sure" that debugger will work flawlessly when Flash is erased, even in (of course) other areas...