Patch from "Randy.Dunlap" <rddunlap@osdl.org>
Reverts the recent alteration of the format of the `mem=' option. This is
because `mem=' is interpreted by bootloaders and may not be freely changed.
Instead, the new functionality to set specific memory region usages is
provided via the new "memmap=" option.
The documentation for memmap= is added, and the documentation for mem= is
updated.
25-akpm/Documentation/kernel-parameters.txt | 32 ++++++++++++++--------------
25-akpm/arch/i386/kernel/setup.c | 29 +++++++++++++++++++++----
2 files changed, 42 insertions(+), 19 deletions(-)
diff -puN arch/i386/kernel/setup.c~fix-mem-equals arch/i386/kernel/setup.c
--- 25/arch/i386/kernel/setup.c~fix-mem-equals Mon Mar 10 14:19:02 2003
+++ 25-akpm/arch/i386/kernel/setup.c Mon Mar 10 14:19:02 2003
@@ -525,8 +525,11 @@ static void __init parse_cmdline_early (
* "mem=nopentium" disables the 4MB page tables.
* "mem=XXX[kKmM]" defines a memory region from HIGH_MEM
* to <mem>, overriding the bios size.
- * "mem=XXX[KkmM]@XXX[KkmM]" defines a memory region from
+ * "memmap=XXX[KkmM]@XXX[KkmM]" defines a memory region from
* <start> to <start>+<mem>, overriding the bios size.
+ *
+ * HPA tells me bootloaders need to parse mem=, so no new
+ * option should be mem= [also see Documentation/i386/boot.txt]
*/
if (c == ' ' && !memcmp(from, "mem=", 4)) {
if (to != command_line)
@@ -535,8 +538,26 @@ static void __init parse_cmdline_early (
from += 9+4;
clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
disable_pse = 1;
- } else if (!memcmp(from+4, "exactmap", 8)) {
- from += 8+4;
+ } else {
+ /* If the user specifies memory size, we
+ * limit the BIOS-provided memory map to
+ * that size. exactmap can be used to specify
+ * the exact map. mem=number can be used to
+ * trim the existing memory map.
+ */
+ unsigned long long mem_size;
+
+ mem_size = memparse(from+4, &from);
+ limit_regions(mem_size);
+ userdef=1;
+ }
+ }
+
+ if (c == ' ' && !memcmp(from, "memmap=", 7)) {
+ if (to != command_line)
+ to--;
+ if (!memcmp(from+7, "exactmap", 8)) {
+ from += 8+7;
e820.nr_map = 0;
userdef = 1;
} else {
@@ -548,7 +569,7 @@ static void __init parse_cmdline_early (
*/
unsigned long long start_at, mem_size;
- mem_size = memparse(from+4, &from);
+ mem_size = memparse(from+7, &from);
if (*from == '@') {
start_at = memparse(from+1, &from);
add_memory_region(start_at, mem_size, E820_RAM);
diff -puN Documentation/kernel-parameters.txt~fix-mem-equals Documentation/kernel-parameters.txt
--- 25/Documentation/kernel-parameters.txt~fix-mem-equals Mon Mar 10 14:19:02 2003
+++ 25-akpm/Documentation/kernel-parameters.txt Mon Mar 10 14:19:02 2003
@@ -71,6 +71,8 @@ In addition, the following text indicate
Parameters denoted with BOOT are actually interpreted by the boot
loader, and have no meaning to the kernel directly.
+Do not modify the syntax of boot loader parameters without extreme
+need or coordination with <Documentation/i386/boot.txt>.
Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
a trailing = on the name of any parameter states that that parameter will
@@ -502,30 +504,30 @@ running once the system is up.
Format: <first>,<last>
Specifies range of consoles to be captured by the MDA.
- mem=exactmap [KNL,BOOT,IA-32] Enable setting of an exact
- E820 memory map, as specified by the user.
- Such mem=exactmap lines can be constructed based on
- BIOS output or other requirements. See the mem=nn@ss
- option description.
-
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used when the kernel is not able
to see the whole system memory or for test.
- mem=nn[KMG]@ss[KMG]
- [KNL,BOOT] Force usage of a specific region of memory
- Region of memory to be used, from ss to ss+nn.
+ mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
+ memory.
- mem=nn[KMG]#ss[KMG]
- [KNL,BOOT,ACPI] Mark specific memory as ACPI data.
+ memmap=exactmap [KNL,IA-32] Enable setting of an exact
+ E820 memory map, as specified by the user.
+ Such memmap=exactmap lines can be constructed based on
+ BIOS output or other requirements. See the memmap=nn@ss
+ option description.
+
+ memmap=nn[KMG]@ss[KMG]
+ [KNL] Force usage of a specific region of memory
Region of memory to be used, from ss to ss+nn.
- mem=nn[KMG]$ss[KMG]
- [KNL,BOOT,ACPI] Mark specific memory as reserved.
+ memmap=nn[KMG]#ss[KMG]
+ [KNL,ACPI] Mark specific memory as ACPI data.
Region of memory to be used, from ss to ss+nn.
- mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
- memory.
+ memmap=nn[KMG]$ss[KMG]
+ [KNL,ACPI] Mark specific memory as reserved.
+ Region of memory to be used, from ss to ss+nn.
memfrac= [KNL]
_