如何计算Framebuffer大小
内核空间Framebuffer大小的计算:
1280*720*4 = 3.5M *2 = 7M(base+ovly)
2. 用户空间Framebuffer大小的计算:
info->fix.line_length = var->xres_virtual * var->bits_per_pixel / 8 = 320 *2=640
info.yres_virtual = info.yres * NUM_BUFFERS = 480*2=960;
size_t fbSize = roundUpToPageSize(finfo.line_length * info.yres_virtual)= 640*960=600K;
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