lib/bootmem: tightly couple bootmem_init to bootmem_write_memory_table

In https://review.coreboot.org/25383 people were confused about the
ordering of bootmem calls w.r.t. when entries are exposed to the OS. To
alleviate this add a notion of bootmem being initialized. In addition to
that, only mark bootmem initialized when bootmem_write_memory_table() is
called. Any other calls to bootmem before that will report an error on
the console.

Change-Id: I5bc31f555038ccabb82d902c54f95858679b1695
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/25503
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/include/bootmem.h

@@ -20,21 +20,18 @@
 #include <stdint.h>
 #include <boot/coreboot_tables.h>
 
-/*
- * Initialize the memory address space prior to payload loading. The bootmem
- * serves as the source for the lb_mem table.
- */
-void bootmem_init(void);
+/* Write memory coreboot table. Current resource map is serialized into
+ * memtable (LB_MEM_* types). bootmem library is unusable until this function
+ * is called first in the write tables path before payload is loaded. */
+void bootmem_write_memory_table(struct lb_memory *mem);
 
-/* Architecture hook to add bootmem areas the architecture controls. */
+/* Architecture hook to add bootmem areas the architecture controls when
+ * bootmem_write_memory_table() is called. */
 void bootmem_arch_add_ranges(void);
 
 /* Add a range of a given type to the bootmem address space. */
 void bootmem_add_range(uint64_t start, uint64_t size, uint32_t type);
 
-/* Write memory coreboot table. */
-void bootmem_write_memory_table(struct lb_memory *mem);
-
 /* Print current range map of boot memory. */
 void bootmem_dump_ranges(void);