diff options
| -rw-r--r-- | lib/x86/fwcfg.c | 4 | ||||
| -rw-r--r-- | lib/x86/fwcfg.h | 1 | ||||
| -rw-r--r-- | lib/x86/setup.c | 7 |
3 files changed, 12 insertions, 0 deletions
diff --git a/lib/x86/fwcfg.c b/lib/x86/fwcfg.c index 06ef62c..c2aaf5a 100644 --- a/lib/x86/fwcfg.c +++ b/lib/x86/fwcfg.c @@ -28,6 +28,10 @@ static void read_cfg_override(void) if ((str = getenv("TEST_DEVICE"))) no_test_device = !atol(str); + if ((str = getenv("MEMLIMIT"))) + fw_override[FW_CFG_MAX_RAM] = atol(str) * 1024 * 1024; + + fw_override_done = true; } diff --git a/lib/x86/fwcfg.h b/lib/x86/fwcfg.h index 2f17461..64d4c6e 100644 --- a/lib/x86/fwcfg.h +++ b/lib/x86/fwcfg.h @@ -21,6 +21,7 @@ #define FW_CFG_BOOT_MENU 0x0e #define FW_CFG_MAX_CPUS 0x0f #define FW_CFG_MAX_ENTRY 0x10 +#define FW_CFG_MAX_RAM 0x11 #define FW_CFG_WRITE_CHANNEL 0x4000 #define FW_CFG_ARCH_LOCAL 0x8000 diff --git a/lib/x86/setup.c b/lib/x86/setup.c index b5941cd..7befe09 100644 --- a/lib/x86/setup.c +++ b/lib/x86/setup.c @@ -66,6 +66,9 @@ void find_highmem(void) u64 upper_end = bootinfo->mem_upper * 1024ull; u64 best_start = (uintptr_t) &edata; u64 best_end = upper_end; + u64 max_end = fwcfg_get_u64(FW_CFG_MAX_RAM); + if (max_end == 0) + max_end = -1ull; bool found = false; uintptr_t mmap = bootinfo->mmap_addr; @@ -79,8 +82,12 @@ void find_highmem(void) continue; if (mem->length < best_end - best_start) continue; + if (mem->base_addr >= max_end) + continue; best_start = mem->base_addr; best_end = mem->base_addr + mem->length; + if (best_end > max_end) + best_end = max_end; found = true; } |