kernel/git/stable/linux.git/drivers/mtd/maps/uclinux.c, branch master

Revert "mtd: maps: remove uclinux map driver"

2026-07-03T13:46:28+00:00

The uclinux MTD map driver is still actively used on ColdFire (m68k) platforms. The ColdFire startup code in arch/m68k/coldfire/head.S copies an attached filesystem blob to _bss_stop, and the uclinux driver picks it up from there. Most ColdFire defconfigs enable CONFIG_MTD_UCLINUX, as the driver seems to serve as a replacement for CONFIG_BLK_DEV_INITRD on these non-MMU targets. The driver was removed as part of a series cleaning up AMD Élan specific drivers, but unlike the other three drivers in that series, this driver seemed to not be as Élan specific (nor unused) as initially thought. This reverts commit c584b8a7ad01a334a89732f3c5791ba14e58642b. Reported-by: Greg Ungerer Closes: https://lore.kernel.org/all/b55ac37f-4523-46d0-8e77-3a17d7235ffe@westnet.com.au/ Acked-by: Arnd Bergmann Signed-off-by: Miquel Raynal

mtd: maps: remove uclinux map driver

2026-05-27T09:19:57+00:00

Rather than using platform data or DT properties, the configuration for this mtd map driver used to be passed through the global uclinux_ram_map structure, but the last instance was removed in commit 4ba66a976072 ("arch: remove blackfin port") in 2018. After commit 251f26c9e828 ("mtd: maps: Make uclinux_ram_map static"), it became impossible to configure it at all, even with out-of-tree platform code. Clearly nobody is using it, so remove it. Signed-off-by: Arnd Bergmann Signed-off-by: Miquel Raynal

mtd: maps: Make uclinux_ram_map static

2019-05-06T19:47:01+00:00

The blackfin architecture has been removed a while ago, so there is no more need to declare uclinux_ram_map as a global structure. Signed-off-by: Thomas Huth Signed-off-by: Richard Weinberger

mtd: constify mtd_partition

2017-11-06T22:26:01+00:00

mtd_partition are not supposed to change at runtime. Functions 'mtd_device_parse_register' working with const mtd_partition provided by . So mark the non-const structs as const. Signed-off-by: Arvind Yadav Signed-off-by: Richard Weinberger

mtd: maps: make uclinux.c driver more explicitly non-modular

2016-04-26T03:19:13+00:00

The Kconfig for this support is currently declared with: config MTD_UCLINUX bool "Generic uClinux RAM/ROM filesystem support" ...meaning that it currently is not being built as a module by anyone. Lets remove as much of the modular evidence that we can, so that when reading the driver there is less doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. We also replace module.h with moduleparam.h since the file does use a module_param, and leaving it as such is currently the easiest way to remain compatible with existing boot arg use cases. We also delete the MODULE_LICENSE tag etc. since all that information was (or is now) contained at the top of the file in the comments. Cc: David Woodhouse Cc: Greg Ungerer Signed-off-by: Paul Gortmaker Signed-off-by: Brian Norris

mtd: uclinux: add a comment about why uclinux_ram_map must not be static

2013-02-04T07:26:30+00:00

I was (at least) the second person trying to fix a warning by sparse, so document in the code why this is a bad idea and add an extern declaration to make sparse happy. Signed-off-by: Uwe Kleine-König Acked-by: Mike Frysinger Acked-by: Greg Ungerer Signed-off-by: Artem Bityutskiy

mtd: uclinux: support ROM and allow passing the base address

2013-02-04T07:26:30+00:00

This allows to put the filesystem at a defined address in ROM allowing to save more precious RAM. I think it's safe to default to ROM because the intention of using the uclinux map is to use a romfs and so mtd-ram doesn't give you anything that mtd-rom doesn't. Signed-off-by: Uwe Kleine-König Acked-by: Greg Ungerer Signed-off-by: Artem Bityutskiy

mtd: fix wrong usage of ioremap_nocache() in uclinux.c map driver

2012-09-29T13:58:05+00:00

The uclinux.c mapping driver uses ioremap_nocache() to map its physical mapping address to a system virtual address. Problem is that the region it is mapping is not device memory. It is ordinary system RAM. On most non-MMU systems this doesn't matter, and the mapping is always a 1:1 translation of the address. On paged memory systems on some architectures the page table mappings are not compatible between normal RAM and device memory. If we want to use the uclinux.c mapping driver on real MMU enabled systems we should be using the kernel virtual address that the mapping is at. For architectures that support the traditional initrd they use phys_to_virt or __va to convert the physical start initrd address to a kernel usable virtual address. The uclinux filesystem mapping is even more restrictive than the typical initrd, it always follows the kernels own bss section (so always in directly mapped memory). Therefore we can use the usual phys_to_virt to translate the physical start address to a virtual address. Signed-off-by: Greg Ungerer Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse

mtd/uclinux: Use generic __bss_stop instead of _ebss

2012-06-27T07:59:43+00:00

The standard (see BSS_SECTION() in and ) symbol for the end of BSS is __bss_stop. This allows to remove all local declarations that have been added to several architectures just to please CONFIG_MTD_UCLINUX. Signed-off-by: Geert Uytterhoeven Acked-by: Paul Mundt Acked-by: Mike Frysinger Acked-by: Michal Simek Acked-by: Greg Ungerer

mtd: add leading underscore to all mtd functions

2012-03-26T23:20:01+00:00

This patch renames all MTD functions by adding a "_" prefix: mtd->erase -> mtd->_erase mtd->read_oob -> mtd->_read_oob ... The reason is that we are re-working the MTD API and from now on it is an error to use MTD function pointers directly - we have a corresponding API call for every pointer. By adding a leading "_" we achieve the following: 1. Make sure we convert every direct pointer users 2. A leading "_" suggests that this interface is internal and it becomes less likely that people will use them directly 3. Make sure all the out-of-tree modules stop compiling and the owners spot the big API change and amend them. Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse