diff --git a/CLAUDE.md b/CLAUDE.md
index 9dd5f17b6eb6..23a9004dd6de 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -119,7 +119,10 @@ The memory map is the same in all three generations: system control at
   data to the load address and enters 0x40 bytes into the zImage, which
   hangs. OpenIPC builds entry = load; vendor kernels need repacking with
   `mkimage -e <load>`.
-- `mem=` is the whole DDR (`osmem` 64M/128M), as the vendor passes it. The
+- `mem=` is the whole DDR (`osmem` 64M/128M), as the vendor passes it,
+  except on the EV200: `osmem` is 40M there, and OpenIPC's EV200 kernel
+  gives the ISP and the encoder the DDR above `mem=` (totalmem - osmem),
+  as the vendor firmware gives them 24 of the 64 MiB. The
   MTD name is `spi0.0` (`SFC`): the vendor kernels' `ak_spiflash` takes
   the SPI device's name. The console is `ttySAK0`.
 
diff --git a/include/configs/openipc-common.h b/include/configs/openipc-common.h
index 279b69790541..4f51b6c6bb70 100644
--- a/include/configs/openipc-common.h
+++ b/include/configs/openipc-common.h
@@ -24,10 +24,14 @@
 #define VENDOR			"anyka"
 
 /*
- * Kernel memory (mem=): all of it, as the vendor U-Boot passes. The media
- * drivers take their buffers from the kernel.
+ * Kernel memory (mem=). The EV200 kernel gives the ISP and the encoder the
+ * DRAM above mem= (totalmem - osmem), as the other OpenIPC SoCs do, and the
+ * vendor firmware gives them 24 MiB of the 64. Elsewhere all of it, as the
+ * vendor U-Boot passes: the media drivers take their buffers from the kernel.
  */
-#if PHYS_SDRAM_1_SIZE == 0x08000000
+#if defined(CONFIG_AK39_EV200)
+#define OPENIPC_OSMEM		"40M"
+#elif PHYS_SDRAM_1_SIZE == 0x08000000
 #define OPENIPC_OSMEM		"128M"
 #else
 #define OPENIPC_OSMEM		"64M"