diff mbox

[for,2.10] mips/malta: leave space for the bootmap after the initrd

Message ID 20170731225210.7829-1-aurelien@aurel32.net
State New
Headers show

Commit Message

Aurelien Jarno July 31, 2017, 10:52 p.m. UTC 
Since commit 9768e2abf7 the initrd is loaded at the end of the low
memory to avoid clash for the kernel relocation when kaslr is used.

However this in turn conflicts with the bootmap memory that the kernel
tries to place after initrd, but in low memory. The bootmap spans the
whole usable physical address space. The machine can have at most 2GiB
of memory, 256MiB of low memory mapped at 0x00000000, and 1792MiB of
high memory mapped at 0x90000000. The biggest bootmap therefore
corresponds to the adresses 0x00000000 -> 0xffffffff, which at 1 bit
per 4kiB page corresponds to 128kiB in memory.

Therefore reserve 128kiB after the initrd.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 hw/mips/mips_malta.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index 8ecd544baa..9dcec27304 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -843,7 +843,10 @@  static int64_t load_kernel (void)
     if (loaderparams.initrd_filename) {
         initrd_size = get_image_size (loaderparams.initrd_filename);
         if (initrd_size > 0) {
-            initrd_offset = (loaderparams.ram_low_size - initrd_size
+            /* The kernel allocates the bootmap memory in the low memory after
+               the initrd.  It takes at most 128kiB for 2GB RAM and 4kiB
+               pages.  */
+            initrd_offset = (loaderparams.ram_low_size - initrd_size - 131072
                              - ~INITRD_PAGE_MASK) & INITRD_PAGE_MASK;
             if (kernel_high >= initrd_offset) {
                 fprintf(stderr,