x86: fsp: Make sure HOB list is not overwritten by U-Boot

[people/ms/u-boot.git] / arch / x86 / lib / fsp / fsp_support.c

diff --git a/arch/x86/lib/fsp/fsp_support.c b/arch/x86/lib/fsp/fsp_support.c
index 29fa06098d1afb30f61e38683538ff62ce119b9f..b05dcede0c40d38ae473c18dec34cf27e313cd19 100644 (file)
--- a/arch/x86/lib/fsp/fsp_support.c
+++ b/arch/x86/lib/fsp/fsp_support.c
@@ -225,6 +225,10 @@ u32 fsp_get_usable_lowmem_top(const void *hob_list)
        struct hob_res_desc *res_desc;
        phys_addr_t phys_start;
        u32 top;
+#ifdef CONFIG_FSP_BROKEN_HOB
+       struct hob_mem_alloc *res_mem;
+       phys_addr_t mem_base = 0;
+#endif
 
        /* Get the HOB list for processing */
        hdr = hob_list;
@@ -242,9 +246,38 @@ u32 fsp_get_usable_lowmem_top(const void *hob_list)
                                        top += (u32)(res_desc->len);
                        }
                }
+
+#ifdef CONFIG_FSP_BROKEN_HOB
+               /*
+                * Find out the lowest memory base address allocated by FSP
+                * for the boot service data
+                */
+               if (hdr->type == HOB_TYPE_MEM_ALLOC) {
+                       res_mem = (struct hob_mem_alloc *)hdr;
+                       if (!mem_base)
+                               mem_base = res_mem->mem_base;
+                       if (res_mem->mem_base < mem_base)
+                               mem_base = res_mem->mem_base;
+               }
+#endif
+
                hdr = get_next_hob(hdr);
        }
 
+#ifdef CONFIG_FSP_BROKEN_HOB
+       /*
+        * Check whether the memory top address is below the FSP HOB list.
+        * If not, use the lowest memory base address allocated by FSP as
+        * the memory top address. This is to prevent U-Boot relocation
+        * overwrites the important boot service data which is used by FSP,
+        * otherwise the subsequent call to fsp_notify() will fail.
+        */
+       if (top > (u32)hob_list) {
+               debug("Adjust memory top address due to a buggy FSP\n");
+               top = (u32)mem_base;
+       }
+#endif
+
        return top;
 }