[Qemu-devel] [RFC/PoC PATCH 1/3] i386: set initrd_max to 4G - 1 to allow up to 4G initrd

[Li Zhijian]

x86/x86_64 has alredy supported 4G initrd.

linux/arch/x86/boot/header.S:
 # (Header version 0x0203 or later) the highest safe address for the contents
 # of an initrd. The current kernel allows up to 4 GB, but leave it at 2 GB to
 # avoid possible bootloader bugs.

CC: Philip Li <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
---
 hw/i386/pc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index cd5029c..e1b910f 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -913,6 +913,12 @@ static void load_linux(PCMachineState *pcms,
     /* highest address for loading the initrd */
     if (protocol >= 0x203) {
         initrd_max = ldl_p(header+0x22c);
+        if (initrd_max == 0x7fffffff) {
+            /* for some reasons, initrd_max is hard code with 0x7fffffff
+             * hard code to 4G - 1 to allow 4G initrd
+             */
+            initrd_max = UINT32_MAX - 1;
+        }
     } else {
         initrd_max = 0x37ffffff;
     }
-- 
2.7.4