From a234da8deb739921a779b33ed6655525b68ec2ec Mon Sep 17 00:00:00 2001
From: mintsuki <mintsuki@protonmail.com>
Date: Fri, 27 Mar 2020 05:58:37 +0100
Subject: [PATCH] Add bpp field to stivale header

---
 src/drivers/vbe.c    | 10 ++++++----
 src/drivers/vbe.h    |  2 +-
 src/protos/stivale.c |  7 +++++--
 test/test.asm        |  7 ++++---
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/drivers/vbe.c b/src/drivers/vbe.c
index dddc3bc6..cd24ab9d 100644
--- a/src/drivers/vbe.c
+++ b/src/drivers/vbe.c
@@ -106,7 +106,7 @@ static int get_edid_info(struct edid_info_struct *buf) {
     return 0;
 }
 
-int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uint16_t *target_height) {
+int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uint16_t *target_height, uint16_t *target_bpp) {
     print("vbe: Initialising...\n");
 
     struct vbe_info_struct vbe_info;
@@ -119,7 +119,8 @@ int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uin
     print("vbe: Product revision: %s\n", (char *)rm_desegment(vbe_info.prod_rev_seg, vbe_info.prod_rev_off));
 
     struct edid_info_struct edid_info;
-    if (!*target_width || !*target_height) {
+    if (!*target_width || !*target_height || !*target_bpp) {
+        *target_bpp = 32;
         if (get_edid_info(&edid_info)) {
             print("vbe: EDID unavailable, defaulting to 1024x768\n");
             *target_width  = 1024;
@@ -132,7 +133,8 @@ int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uin
             *target_height += ((int)edid_info.det_timing_desc1[7] & 0xf0) << 4;
         }
     } else {
-        print("vbe: Requested resolution of %ux%u\n", *target_width, *target_height);
+        print("vbe: Requested resolution of %ux%ux%u\n",
+              *target_width, *target_height, *target_bpp);
     }
 
     uint16_t *vid_modes = (uint16_t *)rm_desegment(vbe_info.vid_modes_seg,
@@ -143,7 +145,7 @@ int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uin
         get_vbe_mode_info(&vbe_mode_info, vid_modes[i]);
         if  (vbe_mode_info.res_x == *target_width
           && vbe_mode_info.res_y == *target_height
-          && vbe_mode_info.bpp   == 32) {
+          && vbe_mode_info.bpp   == *target_bpp) {
             print("vbe: Found matching mode %x, attempting to set\n", vid_modes[i]);
             *framebuffer = (uint64_t)vbe_mode_info.framebuffer;
             *pitch       = (int)vbe_mode_info.pitch;
diff --git a/src/drivers/vbe.h b/src/drivers/vbe.h
index d7765595..180deb1a 100644
--- a/src/drivers/vbe.h
+++ b/src/drivers/vbe.h
@@ -1,6 +1,6 @@
 #ifndef __DRIVERS__VBE_H__
 #define __DRIVERS__VBE_H__
 
-int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uint16_t *target_height);
+int init_vbe(uint64_t *framebuffer, uint16_t *pitch, uint16_t *target_width, uint16_t *target_height, uint16_t *target_bpp);
 
 #endif
diff --git a/src/protos/stivale.c b/src/protos/stivale.c
index a6d02400..2d902234 100644
--- a/src/protos/stivale.c
+++ b/src/protos/stivale.c
@@ -9,9 +9,10 @@
 
 struct stivale_header {
     uint64_t stack;
-    uint8_t  video_mode;  // 0 = default at boot (CGA text mode). 1 = graphical VESA
+    uint16_t video_mode;  // 0 = default at boot (CGA text mode). 1 = graphical VESA
     uint16_t framebuffer_width;
     uint16_t framebuffer_height;
+    uint16_t framebuffer_bpp;
 } __attribute__((packed));
 
 struct stivale_module {
@@ -68,12 +69,14 @@ void stivale_load(struct echfs_file_handle *fd) {
 
     stivale_struct.framebuffer_width  = stivale_hdr.framebuffer_width;
     stivale_struct.framebuffer_height = stivale_hdr.framebuffer_height;
+    stivale_struct.framebuffer_bpp    = stivale_hdr.framebuffer_bpp;
 
     if (stivale_hdr.video_mode == 1) {
         init_vbe(&stivale_struct.framebuffer_addr,
                  &stivale_struct.framebuffer_pitch,
                  &stivale_struct.framebuffer_width,
-                 &stivale_struct.framebuffer_height);
+                 &stivale_struct.framebuffer_height,
+                 &stivale_struct.framebuffer_bpp);
     }
 
     volatile struct {
diff --git a/test/test.asm b/test/test.asm
index 69aee3e2..5b65394e 100644
--- a/test/test.asm
+++ b/test/test.asm
@@ -5,9 +5,10 @@ section .stivalehdr
 
 stivale_header:
     dq stack.top    ; rsp
-    db 1            ; video mode
-    dw 0          ; fb_width
-    dw 0          ; fb_height
+    dw 1            ; video mode
+    dw 800          ; fb_width
+    dw 600          ; fb_height
+    dw 16          ; fb_bpp
 
 section .bss