diff options
| author | Doug Anderson <dianders@chromium.org> | 2012-02-02 22:58:28 -0800 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2016-02-16 13:54:08 -0800 |
| commit | d2e94f417f7f5fcd227f44ccea88e00cf6dd2d8d (patch) | |
| tree | 22fdc75c7f81bcac8e646c42f55c46a44e759437 /include/linux | |
| parent | 5813f5dee4a7da1621c15351acbcaf9718582f5b (diff) | |
of: Support CONFIG_CMDLINE_EXTEND config option
The old logic assumes CMDLINE_FROM_BOOTLOADER vs. CMDLINE_FORCE and
ignores CMDLINE_EXTEND. Here's the old logic:
- CONFIG_CMDLINE_FORCE=true
CONFIG_CMDLINE
- dt bootargs=non-empty:
dt bootargs
- dt bootargs=empty, @data is non-empty string
@data is left unchanged
- dt bootargs=empty, @data is empty string
CONFIG_CMDLINE (or "" if that's not defined)
The new logic is now documented in of_fdt.h and is copied here for
reference:
- CONFIG_CMDLINE_FORCE=true
CONFIG_CMDLINE
- CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
@data + dt bootargs (even if dt bootargs are empty)
- CONFIG_CMDLINE_EXTEND=true, @data is empty string
CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
dt bootargs
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
@data is left unchanged
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
CONFIG_CMDLINE (or "" if that's not defined)
Signed-off-by: Doug Anderson <dianders@chromium.org>
CC: devicetree-discuss@lists.ozlabs.org
CC: Grant Likely <grant.likely@secretlab.ca>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Rob Herring <rob.herring@calxeda.com>
Change-Id: I40ace250847f813358125dfcaa8998fd32cf7ea3
Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/of_fdt.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index df9ef3801812..fbbb89b69012 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -59,6 +59,27 @@ extern int of_flat_dt_match(unsigned long node, const char *const *matches); extern unsigned long of_get_flat_dt_root(void); extern int of_get_flat_dt_size(void); +/* + * early_init_dt_scan_chosen - scan the device tree for ramdisk and bootargs + * + * The boot arguments will be placed into the memory pointed to by @data. + * That memory should be COMMAND_LINE_SIZE big and initialized to be a valid + * (possibly empty) string. Logic for what will be in @data after this + * function finishes: + * + * - CONFIG_CMDLINE_FORCE=true + * CONFIG_CMDLINE + * - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string + * @data + dt bootargs (even if dt bootargs are empty) + * - CONFIG_CMDLINE_EXTEND=true, @data is empty string + * CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty) + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty: + * dt bootargs + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string + * @data is left unchanged + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string + * CONFIG_CMDLINE (or "" if that's not defined) + */ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, int depth, void *data); extern int early_init_dt_scan_memory(unsigned long node, const char *uname, |