How to adapt the old OpenGL ES 1 setup to iPhone 6 Plus?

If I'm not the last man on earth using the very 1st version of OpenGL ES: has anyone dealt with adapting the resizeFromLayer function to the new 3x scaling on iPhone 6 Plus?

The code below works perfectly for all previous iPhones:

- (BOOL)resizeFromLayer:(CAEAGLLayer *)layer {
glGenFramebuffersOES(1, &viewFramebuffer);
glGenRenderbuffersOES(1, &viewRenderbuffer);

glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
[context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:layer];
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);

glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);

glGenRenderbuffersOES(1, &depthRenderbuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

const GLfloat zNear = 0.1f, zFar = 8100.0f, fieldOfView = 60.0;
CGRect rect = layer.bounds;
GLfloat size;

glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_MODELVIEW);
size = zNear * tanf(DEGREES_TO_RADIANS(fieldOfView) / 2.0);

glFrustumf(-size, size, -size / (rect.size.width / rect.size.height), size / (rect.size.width / rect.size.height), zNear, zFar);

glRotatef(-90.0, 0.0, 0.0, 1.0);

if (glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES)
{
    NSLog(@"Failed to make complete framebuffer object %x", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
    return NO;
}

return YES;

}

Although I've updated the launch images for new phones (so the app detects 414x736 points), it still seems to act like it's working in 'zoomed mode' (for older apps).

Anyone sees a solution? I'd really appreciate your help.