From 7360362e24431c0bde7044bd2e282c5c53bed69a Mon Sep 17 00:00:00 2001
From: acevest <zhaoyanbai@126.com>
Date: Thu, 12 Oct 2023 18:58:22 +0800
Subject: [PATCH] =?utf8?q?VBE=E7=9B=B8=E5=85=B3=E9=80=BB=E8=BE=91=E4=BF=AE?=
 =?utf8?q?=E6=94=B9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

---
 .gitignore       |  1 +
 boot/boot.c      | 11 +++----
 boot/multiboot.S | 15 +++++++--
 boot/vbe.c       | 84 +++++++++++++++++++++++++++++++++++++++++++++++-
 gdbscript        |  4 ++-
 5 files changed, 105 insertions(+), 10 deletions(-)

diff --git a/.gitignore b/.gitignore
index cba73dc..603e279 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,4 @@ bochsout.txt
 *.DS_Store
 .vscode/settings.json
 *.iso
+**/serial_monitor/serial_monitor
diff --git a/boot/boot.c b/boot/boot.c
index 339d744..a29fab4 100644
--- a/boot/boot.c
+++ b/boot/boot.c
@@ -100,6 +100,7 @@ void check_kernel(unsigned long addr, unsigned long magic) {
     boot_params.e820map.map_cnt = 0;
 
     while (tag->type != MULTIBOOT_TAG_TYPE_END) {
+        bool support = true;
         switch (tag->type) {
         case MULTIBOOT_TAG_TYPE_CMDLINE:
             strlcpy(boot_params.cmdline, ((struct multiboot_tag_string *)tag)->string, sizeof(boot_params.cmdline));
@@ -137,19 +138,17 @@ void check_kernel(unsigned long addr, unsigned long magic) {
             vbe = (struct multiboot_tag_vbe *)tag;
             void *vci = (void *)vbe->vbe_control_info.external_specification;
             void *vmi = (void *)vbe->vbe_mode_info.external_specification;
-            // vbe->vbe_control_info;
-            // asm volatile("xchg %%bx, %%bx;nop;nop;" ::"a"(vci), "b"(vmi));
-            // asm volatile("xchg %%bx, %%bx;nop;nop;" ::"a"(vbe->vbe_interface_seg), "b"(vbe->vbe_interface_off),
-            //              "c"(vbe->vbe_interface_len));
+            printk("VBE MODE %04x\n", vbe->vbe_mode);
             init_vbe(vci, vmi);
             break;
         case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
-            // asm volatile("xchg %bx, %bx;nop;nop;nop;nop;");
+            printk("frame buffer\n");
             break;
         default:
-            printk("tag %x size %x\n", tag->type, tag->size);
+            support = false;
             break;
         }
+        printk("tag %x size %x\t[%ssupport]\n", tag->type, tag->size, support ? "" : "un");
         // next tag
         unsigned long size = (tag->size + 7) & (~7UL);
         tag = (struct multiboot_tag *)(((unsigned long)tag) + size);
diff --git a/boot/multiboot.S b/boot/multiboot.S
index aad20a0..3791f26 100644
--- a/boot/multiboot.S
+++ b/boot/multiboot.S
@@ -172,8 +172,19 @@ multiboot2_header_bgn:
     // .short MULTIBOOT_HEADER_TAG_FRAMEBUFFER
     // .short MULTIBOOT_HEADER_TAG_OPTIONAL
     // .long .framebuffer_tag_end - .framebuffer_tag_bgn
-    // .long 800
-    // .long 600
+    // # width
+    // # Contains the number of the columns. This is specified in pixels in a graphics mode,
+    // # and in characters in a text mode.
+    // # The value zero indicates that the OS image has no preference.
+    // .long 1024
+    // # height
+    // # Contains the number of the lines. This is specified in pixels in a graphics mode,
+    // # and in characters in a text mode.
+    // # The value zero indicates that the OS image has no preference.
+    // .long 768
+    // # depth
+    // # Contains the number of bits per pixel in a graphics mode, and zero in a text mode.
+    // # The value zero indicates that the OS image has no preference.
     // .long 32
     // .framebuffer_tag_end:
 
diff --git a/boot/vbe.c b/boot/vbe.c
index d6a6ac4..598905d 100644
--- a/boot/vbe.c
+++ b/boot/vbe.c
@@ -12,6 +12,58 @@
 #include <system.h>
 #include <types.h>
 
+// VESA BIOS Extensions
+
+// VGA
+// VGA（Video Graphics Array）即视频图形阵列，是IBM在1987年随PS/2机推出的。
+// VGA主要由七大块组成：图形控制器、显示存储器、定序器、CRT控制器、数据串行发生器、属性控制器和数模转换器DAC。
+
+// VBE
+// IBM的VGA标准是显示卡发展史上的一块丰碑。但后来无法满足人们的需要，于是市场上出现了TVGA、S3系列、Cirrus
+// Logic、ET等为首的一批显示卡，提供了比VGA分辨率更高，颜色更丰富的显示模式，又兼容VGA显示卡，它们被统称为Super
+// VGA（SVGA）。 各种不同的SVGA之间的显示控制各不相同，带来软件兼容性问题，为此视频电子学标准协会VESA（Video Electronics
+// Standards Association）提出了一组附加的BIOS功能调用接口——VBE（VESA BIOS EXTENSION）标准，
+// 从而在软件接口层次上实现了各种SVGA显示卡之间的兼容性。时至今日，所有的显示卡OEM厂商都提供了符合VESA
+// SUPER标准的扩展BIOS 通过一组INT 10H中断调用（AH=4FH），可以方便地使用VESA
+// SVGA的扩展功能而不必了解各种显示卡的硬件细节。 Super VGA 的扩充显示能力关键取决于对较大显示存储器的寻址能力。 各Super
+// VGA 卡提供的分辨率远高于VGA，VESA VBE均赋予一个标准的16位模式号（实际上是9位，其他各位为标志位或留给以后扩充）。
+
+// typedef uint8_t BCD;
+// typedef struct vg_vbe_contr_info {
+//     char VBESignature[4];
+//     BCD VBEVersion[2];
+//     char *OEMString;
+//     uint16_t *VideoModeList;
+//     uint32_t TotalMemory;
+//     char *OEMVendorNamePtr;
+//     char *OEMProductNamePtr;
+//     char *OEMProductRevPtr;
+// } vg_vbe_contr_info_t;
+
+#define VBE_MODE_END 0xFFFF
+typedef struct segoff {
+    uint16_t offset;
+    uint16_t segment;
+} __attribute__((packed)) segoff_t;
+
+// typedef uint32_t segoff_t;
+typedef struct vbe_controller_info {
+    uint8_t signature[4];  // 'VESA'
+    uint16_t version;      // BCD
+    // uint8_t major_version;  // BCD
+    // uint8_t minor_version;  // BCD
+    segoff_t oem_string_ptr;
+    uint8_t capabilities[4];
+    segoff_t video_mode_ptr;
+    uint16_t total_memory;  // Number of 64kB memory blocks.
+    // ... 更多 VBE 3.0+ 字段
+    uint16_t oem_software_rev;
+    segoff_t oem_vendor_name_ptr;
+    segoff_t oem_product_name_ptr;
+    segoff_t oem_product_rev_ptr;
+    uint8_t reserved[222];
+} __attribute__((packed)) vbe_controller_info_t;
+
 typedef struct vbe_mode_info {
     u16 mode_attributes;
     u8 wina_attributes;
@@ -62,11 +114,41 @@ typedef struct vbe_mode_info {
 
 // pte_t vbe_pte[PTECNT_PER_PAGE] __attribute__((__aligned__(PAGE_SIZE)));
 
+uint32_t segoff_to_addr(segoff_t sg) { return 0xC0000000 + (sg.segment << 4) + sg.offset; }
+
+vbe_mode_info_t *get_vbe_mode_info(uint16_t) {
+    // 设置并执行实模式代码以调用 VBE 函数 0x4F01
+    // 返回指向 VBE 模式信息的指针
+    return NULL;
+}
 // extern pde_t init_pgd[];
 void init_vbe(void *vciptr, void *vmiptr) {
+    vbe_controller_info_t *vci = vciptr;
     vbe_mode_info_t *vmi = (vbe_mode_info_t *)vmiptr;
 
+    printk("VBE:\n");
+    printk("Signature %c%c%c%c\n", vci->signature[0], vci->signature[1], vci->signature[2], vci->signature[3]);
+    printk("version %04x\n", vci->version);
+    printk("total memory %u x 64K\n", vci->total_memory);
+    printk("OEM software rev: %04X\n", vci->oem_software_rev);
+    printk("OEM vendor: %s\n", segoff_to_addr(vci->oem_vendor_name_ptr));
+    printk("OEM product name: %s\n", segoff_to_addr(vci->oem_product_name_ptr));
+    printk("OEM product rev: %s\n", segoff_to_addr(vci->oem_product_rev_ptr));
+
+    printk("SEG %04X OFFSET %04X\n", vci->video_mode_ptr.segment, vci->video_mode_ptr.offset);
+    uint16_t *modes = (uint16_t *)segoff_to_addr(vci->video_mode_ptr);
+    while (*modes != VBE_MODE_END) {
+        printk("mode: %04x\n", *modes);
+        // vbe_mode_info_t *mi = get_vbe_mode_info(*modes);
+        // if (mi->mode_attributes & 0x01) {
+        //     printk("R %u x %u\n", mi->x_resolution, mi->y_resolution);
+        // }
+        modes++;
+    }
+
     system.vbe_phys_addr = vmi->phys_base_ptr;
     system.x_resolution = vmi->x_resolution;
     system.y_resolution = vmi->y_resolution;
-}
\ No newline at end of file
+
+    printk(" phys addr %08x resolution %u x %u\n", system.vbe_phys_addr, system.x_resolution, system.y_resolution);
+}
diff --git a/gdbscript b/gdbscript
index 9dd6925..3af0e80 100644
--- a/gdbscript
+++ b/gdbscript
@@ -8,8 +8,10 @@
 # watch point
 #wa *0x7c00
 
-target remote localhost:1234
+break *0x100000
+# break *0xC0100000
 
+target remote localhost:1234
 
 set pagination off
 
-- 
2.44.0