Make the device tree available in the rom stage

We thought about two ways to do this change. The way we decided to try
was to
1. drop all ops from devices in romstage
2. constify all devices in romstage (make them read-only) so we can
   compile static.c into romstage
3. the device tree "devices" can be used to read configuration from
   the device tree (and nothing else, really)
4. the device tree devices are accessed through struct device * in
   romstage only. device_t stays the typedef to int in romstage
5. Use the same static.c file in ramstage and romstage

We declare structs as follows:
ROMSTAGE_CONST struct bus dev_root_links[];
ROMSTAGE_CONST is const in romstage and empty in ramstage; This
forces all of the device tree into the text area.

So a struct looks like this:
static ROMSTAGE_CONST struct device _dev21 = {
 #ifndef __PRE_RAM__
        .ops = 0,
 #endif
        .bus = &_dev7_links[0],
        .path = {.type=DEVICE_PATH_PCI,{.pci={ .devfn = PCI_DEVFN(0x1c,3)}}},
        .enabled = 0,
        .on_mainboard = 1,
        .subsystem_vendor = 0x1ae0,
        .subsystem_device = 0xc000,
        .link_list = NULL,
        .sibling = &_dev22,
 #ifndef __PRE_RAM__
        .chip_ops = &southbridge_intel_bd82x6x_ops,
 #endif
        .chip_info = &southbridge_intel_bd82x6x_info_10,
        .next=&_dev22
};

Change-Id: I722454d8d3c40baf7df989f5a6891f6ba7db5727
Signed-off-by: Ronald G. Minnich <rminnich@chromium.org>
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1398
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 20 insertions, 12 deletions

diff --git a/util/sconfig/main.c b/util/sconfig/main.c
index 824bc6c17840..82a7491d8510 100644
--- a/util/sconfig/main.c
+++ b/util/sconfig/main.c
@@ -366,13 +366,15 @@ void add_ioapic_info(struct device *dev, int apicid, const char *_srcpin, int ir
 
 static void pass0(FILE *fil, struct device *ptr) {
 	if (ptr->type == device && ptr->id == 0)
-		fprintf(fil, "struct bus %s_links[];\n", ptr->name);
+		fprintf(fil, "ROMSTAGE_CONST struct bus %s_links[];\n", ptr->name);
+
 	if ((ptr->type == device) && (ptr->id != 0) && (!ptr->used)) {
-		fprintf(fil, "static struct device %s;\n", ptr->name);
+		fprintf(fil, "ROMSTAGE_CONST static struct device %s;\n", ptr->name);
 		if (ptr->rescnt > 0)
-			fprintf(fil, "struct resource %s_res[];\n", ptr->name);
+			fprintf(fil, "ROMSTAGE_CONST struct resource %s_res[];\n", ptr->name);
 		if (ptr->children || ptr->multidev)
-			fprintf(fil, "struct bus %s_links[];\n", ptr->name);
+			fprintf(fil, "ROMSTAGE_CONST struct bus %s_links[];\n",
+					ptr->name);
 	}
 }
 
@@ -382,8 +384,10 @@ static void pass1(FILE *fil, struct device *ptr)
 	if (!ptr->used && (ptr->type == device)) {
 		if (ptr->id != 0)
 			fprintf(fil, "static ");
-		fprintf(fil, "struct device %s = {\n", ptr->name);
+		fprintf(fil, "ROMSTAGE_CONST struct device %s = {\n", ptr->name);
+		fprintf(fil, "#ifndef __PRE_RAM__\n");
 		fprintf(fil, "\t.ops = %s,\n", (ptr->ops)?(ptr->ops):"0");
+		fprintf(fil, "#endif\n");
 		fprintf(fil, "\t.bus = &%s_links[%d],\n", ptr->bus->name, ptr->bus->link);
 		fprintf(fil, "\t.path = {");
 		fprintf(fil, ptr->path, ptr->path_a, ptr->path_b);
@@ -415,7 +419,9 @@ static void pass1(FILE *fil, struct device *ptr)
 		if (ptr->sibling)
 			fprintf(fil, "\t.sibling = &%s,\n", ptr->sibling->name);
 		if (ptr->chip->chiph_exists) {
+			fprintf(fil, "#ifndef __PRE_RAM__\n");
 			fprintf(fil, "\t.chip_ops = &%s_ops,\n", ptr->chip->name_underscore);
+			fprintf(fil, "#endif\n");
 			fprintf(fil, "\t.chip_info = &%s_info_%d,\n", ptr->chip->name_underscore, ptr->chip->id);
 		}
 		if (ptr->nextdev)
@@ -424,7 +430,8 @@ static void pass1(FILE *fil, struct device *ptr)
 	}
 	if (ptr->rescnt > 0) {
 		int i=1;
-		fprintf(fil, "struct resource %s_res[] = {\n", ptr->name);
+		fprintf(fil, "ROMSTAGE_CONST struct resource %s_res[] = {\n",
+				ptr->name);
 		struct resource *r = ptr->res;
 		while (r) {
 			fprintf(fil, "\t\t{ .flags=IORESOURCE_FIXED | IORESOURCE_ASSIGNED | IORESOURCE_");
@@ -441,7 +448,7 @@ static void pass1(FILE *fil, struct device *ptr)
 		fprintf(fil, "\t };\n");
 	}
 	if (!ptr->used && ptr->type == device && (ptr->children || ptr->multidev)) {
-		fprintf(fil, "struct bus %s_links[] = {\n", ptr->name);
+		fprintf(fil, "ROMSTAGE_CONST struct bus %s_links[] = {\n", ptr->name);
 		if (ptr->multidev) {
 			struct device *d = ptr;
 			while (d) {
@@ -473,8 +480,9 @@ static void pass1(FILE *fil, struct device *ptr)
 	}
 	if ((ptr->type == chip) && (ptr->chiph_exists)) {
 		if (ptr->reg) {
-			fprintf(fil, "struct %s_config %s_info_%d\t= {\n",
-				ptr->name_underscore, ptr->name_underscore, ptr->id);
+			fprintf(fil, "ROMSTAGE_CONST struct %s_config ROMSTAGE_CONST %s_info_%d = {\n",
+				ptr->name_underscore, ptr->name_underscore,
+				ptr->id);
 			struct reg *r = ptr->reg;
 			while (r) {
 				fprintf(fil, "\t.%s = %s,\n", r->key, r->value);
@@ -482,7 +490,7 @@ static void pass1(FILE *fil, struct device *ptr)
 			}
 			fprintf(fil, "};\n\n");
 		} else {
-			fprintf(fil, "struct %s_config %s_info_%d;\n",
+			fprintf(fil, "ROMSTAGE_CONST struct %s_config ROMSTAGE_CONST %s_info_%d = { };\n",
 				ptr->name_underscore, ptr->name_underscore, ptr->id);
 		}
 	}
@@ -617,9 +625,9 @@ int main(int argc, char** argv) {
 		fprintf(autogen, "\n/* pass 0 */\n");
 		walk_device_tree(autogen, &root, pass0, NULL);
 		fprintf(autogen, "\n/* pass 1 */\n"
-			    "struct device *last_dev = &%s;\n", lastdev->name);
+			    "ROMSTAGE_CONST struct device * ROMSTAGE_CONST last_dev = &%s;\n", lastdev->name);
 #ifdef MAINBOARDS_HAVE_CHIP_H
-		fprintf(autogen, "struct mainboard_config mainboard_info_0;\n");
+		fprintf(autogen, "static ROMSTAGE_CONST struct mainboard_config ROMSTAGE_CONST mainboard_info_0;\n");
 #endif
 		walk_device_tree(autogen, &root, pass1, NULL);