console: Make persistent scrollback a boot parameter (1a336c93) · Commits · 戴 / test

drivers/video/console/Kconfig

+7 −5

Original line number	Diff line number	Diff line
		@@ -47,14 +47,16 @@ config VGACON_SOFT_SCROLLBACK_SIZE
		buffers of VGA consoles. Each 64KB will give you approximately
		16 80x25 screenfuls of scrollback buffer.

		config VGACON_SOFT_SCROLLBACK_PERSISTENT
		bool "Persistent Scrollback History for each console"
		config VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT
		bool "Persistent Scrollback History for each console by default"
		depends on VGACON_SOFT_SCROLLBACK
		default n
		help
		Say Y here if the scrollback history should persist when switching
		between consoles. Otherwise, the scrollback history will be flushed
		each time the console is switched.
		Say Y here if the scrollback history should persist by default when
		switching between consoles. Otherwise, the scrollback history will be
		flushed each time the console is switched. This feature can also be
		enabled using the boot command line parameter
		'vgacon.scrollback_persistent=1'.

		This feature might break your tool of choice to flush the scrollback
		buffer, e.g. clear(1) will work fine but Debian's clear_console(1)

+12 −13

Original line number	Diff line number	Diff line
		@@ -174,11 +174,11 @@ struct vgacon_scrollback_info {
		};

		static struct vgacon_scrollback_info *vgacon_scrollback_cur;
		#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
		static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES];
		#else
		static struct vgacon_scrollback_info vgacon_scrollbacks[1];
		#endif
		static bool scrollback_persistent = \
		IS_ENABLED(CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT_ENABLE_BY_DEFAULT);
		module_param_named(scrollback_persistent, scrollback_persistent, bool, 0000);
		MODULE_PARM_DESC(scrollback_persistent, "Enable persistent scrollback for all vga consoles");

		static void vgacon_scrollback_reset(int vc_num, size_t reset_size)
		{
		@@ -213,20 +213,19 @@ static void vgacon_scrollback_init(int vc_num)

		static void vgacon_scrollback_switch(int vc_num)
		{
		#ifndef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
		if (!scrollback_persistent)
		vc_num = 0;
		#endif

		if (!vgacon_scrollbacks[vc_num].data) {
		vgacon_scrollback_init(vc_num);
		} else {
		#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT
		if (scrollback_persistent) {
		vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num];
		#else
		} else {
		size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024;

		vgacon_scrollback_reset(vc_num, size);
		#endif
		}
		}
		}