Plug in e820 driver

src/lib/e820.c

@@ -21,10 +21,11 @@ static const char *e820_type(uint32_t type) {
     }
 }
 
-void init_e820(void) {
+int init_e820(void) {
     struct rm_regs r = {0};
 
-    for (size_t i = 0; i < E820_MAX_ENTRIES; i++) {
+    int entry_count;
+    for (int i = 0; i < E820_MAX_ENTRIES; i++) {
         r.eax = 0xe820;
         r.ecx = 24;
         r.edx = 0x534d4150;
@@ -32,24 +33,27 @@ void init_e820(void) {
         rm_int(0x15, &r, &r);
 
         if (r.eflags & EFLAGS_CF) {
-            e820_map[i].type = 0;
+            entry_count = i;
             goto done;
         }
 
         if (!r.ebx) {
-            e820_map[i+1].type = 0;
+            entry_count = ++i;
             goto done;
         }
     }
 
     print("e820: Too many entries!\n");
+    for (;;);
 
 done:
-    for (size_t i = 0; e820_map[i].type; i++) {
+    for (int i = 0; i < entry_count; i++) {
         print("e820: [%X -> %X] : %X  <%s>\n",
               e820_map[i].base,
               e820_map[i].base + e820_map[i].length,
               e820_map[i].length,
               e820_type(e820_map[i].type));
     }
+
+    return entry_count;
 }

src/lib/e820.h

@@ -14,6 +14,6 @@ struct e820_entry_t {
 
 extern struct e820_entry_t e820_map[E820_MAX_ENTRIES];
 
-void init_e820(void);
+int init_e820(void);
 
 #endif

src/protos/stivale.c

@@ -4,6 +4,7 @@
 #include <lib/elf.h>
 #include <lib/blib.h>
 #include <lib/acpi.h>
+#include <lib/e820.h>
 #include <drivers/vbe.h>
 
 struct stivale_header {
@@ -59,6 +60,9 @@ void stivale_load(struct echfs_file_handle *fd) {
 
     elf_load(fd, &entry_point);
 
+    stivale_struct.memory_map_entries = (uint64_t)init_e820();
+    stivale_struct.memory_map_addr    = (uint64_t)(size_t)e820_map;
+
     stivale_struct.rsdp = (uint64_t)(size_t)get_rsdp();
     print("stivale: RSDP at %X\n", stivale_struct.rsdp);
 

test/test.asm

@@ -24,7 +24,8 @@ _start:
     mov rax, 'h e l l '
     mov rbx, 'o   w o '
     mov rcx, 'r l d   '
-    mov [0xb8000], rax
-    mov [0xb8008], rbx
-    mov [0xb8010], rcx
+    mov rdx, [rdi+20]
+    mov [rdx], rax
+    mov [rdx+8], rbx
+    mov [rdx+16], rcx
     jmp $