Patch SeaBIOS: Add MXM support

Signed-off-by: Riku Viitanen <riku.viitanen@protonmail.com>

2 files changed, 274 insertions, 0 deletions

diff --git a/config/seabios/default/patches/0001-romfile-implement-a-generic-loader.patch b/config/seabios/default/patches/0001-romfile-implement-a-generic-loader.patch
new file mode 100644
index 0000000..f0682c1
--- /dev/null
+++ b/config/seabios/default/patches/0001-romfile-implement-a-generic-loader.patch
@@ -0,0 +1,86 @@
+From 2aff8adc1dcd1315877fdb4ac4ef5e649c5b7d11 Mon Sep 17 00:00:00 2001
+From: Riku Viitanen <riku.viitanen@protonmail.com>
+Date: Sat, 10 Feb 2024 21:23:33 +0200
+Subject: [PATCH 1/2] romfile: implement a generic loader
+
+romfile_loadfile_g:
+Based on romfile_loadfile but more flexible. User has to supply pointer
+to a malloc function and the number of trailing padding bytes. Thus, any
+memory region may be used.
+
+romfile_loadfile:
+It is now a wrapper around romfile_loadfile_g. Functionality is the same.
+
+Signed-off-by: Riku Viitanen <riku.viitanen@protonmail.com>
+---
+ src/romfile.c | 25 ++++++++++++++++++++-----
+ src/romfile.h |  2 ++
+ 2 files changed, 22 insertions(+), 5 deletions(-)
+
+diff --git a/src/romfile.c b/src/romfile.c
+index b598274e..8bf95713 100644
+--- a/src/romfile.c
++++ b/src/romfile.c
+@@ -47,10 +47,12 @@ romfile_find(const char *name)
+     return __romfile_findprefix(name, strlen(name) + 1, NULL);
+ }
+ 
+-// Helper function to find, malloc_tmphigh, and copy a romfile.  This
+-// function adds a trailing zero to the malloc'd copy.
++// Generic function to find romfile, malloc (using provided function
++// pointer), and copy a romfile. add_len specifies how many additional
++// trailing bytes to reserve. The extra bytes will not be initialised.
+ void *
+-romfile_loadfile(const char *name, int *psize)
++romfile_loadfile_g(const char *name, int *psize,
++                   void *(*malloc_fn)(), int add_len)
+ {
+     struct romfile_s *file = romfile_find(name);
+     if (!file)
+@@ -60,7 +62,7 @@ romfile_loadfile(const char *name, int *psize)
+     if (!filesize)
+         return NULL;
+ 
+-    char *data = malloc_tmphigh(filesize+1);
++    char *data = malloc_fn(filesize+add_len);
+     if (!data) {
+         warn_noalloc();
+         return NULL;
+@@ -74,7 +76,20 @@ romfile_loadfile(const char *name, int *psize)
+     }
+     if (psize)
+         *psize = filesize;
+-    data[filesize] = '\0';
++
++    return data;
++}
++
++// Helper function to find, malloc_tmphigh, and copy a romfile.  This
++// function adds a trailing zero to the malloc'd copy.
++void *
++romfile_loadfile(const char *name, int *psize)
++{
++    char *data = romfile_loadfile_g(name, psize, &malloc_tmphigh, 1);
++    if (!data)
++        return NULL;
++
++    data[*psize] = '\0';
+     return data;
+ }
+ 
+diff --git a/src/romfile.h b/src/romfile.h
+index 3e0f8200..a320a5bc 100644
+--- a/src/romfile.h
++++ b/src/romfile.h
+@@ -13,6 +13,8 @@ struct romfile_s {
+ void romfile_add(struct romfile_s *file);
+ struct romfile_s *romfile_findprefix(const char *prefix, struct romfile_s *prev);
+ struct romfile_s *romfile_find(const char *name);
++void *romfile_loadfile_g(const char *name, int *psize,
++                         void *(*malloc_fn)(), int add_len);
+ void *romfile_loadfile(const char *name, int *psize);
+ u64 romfile_loadint(const char *name, u64 defval);
+ 
+-- 
+2.43.0
+
diff --git a/config/seabios/default/patches/0002-vgahooks-optionroms-implement-mxm-3.0-interrupts.patch b/config/seabios/default/patches/0002-vgahooks-optionroms-implement-mxm-3.0-interrupts.patch
new file mode 100644
index 0000000..f05a34c
--- /dev/null
+++ b/config/seabios/default/patches/0002-vgahooks-optionroms-implement-mxm-3.0-interrupts.patch
@@ -0,0 +1,188 @@
+From 1e7c443d069ef817c4e699bd6675efff4ebddb86 Mon Sep 17 00:00:00 2001
+From: Riku Viitanen <riku.viitanen@protonmail.com>
+Date: Sat, 10 Feb 2024 21:38:17 +0200
+Subject: [PATCH 2/2] vgahooks, optionroms: implement mxm 3.0 interrupts
+
+VGAROMs on MXM graphics cards need certain int15h functions present.
+
+Tested on a HP EliteBook 8560w with coreboot and Quadro 2000M. A warning
+is displayed for 30 seconds and performance is nerfed:
+
+	ERROR: Valid MXM Structure not found.
+	POST halted for 30 seconds, P-state limited to P10...
+
+This patch implements the minimum required on this system (and implemented
+by the OEM BIOS): functions 0 and 1.
+
+These functions are specific to the MXM 3.0 Software Specification,
+earlier versions are not implemented due to lack of hardware. Documentation
+for versions 2.1 and 3.0 can be found freely online.
+
+Functions aren't specific to mainboards or GPUs (though some mainboards
+could need more functions implemented). The structure is
+mainboard-specific and is read from romfile "mxm-30-sis".
+
+It can be extracted from vendor BIOS by running those same interrupts.
+I wrote a tool to do it on Linux: https://codeberg.org/Riku_V/mxmdump/
+
+Signed-off-by: Riku Viitanen <riku.viitanen@protonmail.com>
+---
+ src/optionroms.c |  9 +++++++
+ src/vgahooks.c   | 69 ++++++++++++++++++++++++++++++++++++++++++++++++
+ src/vgahooks.h   |  9 +++++++
+ 3 files changed, 87 insertions(+)
+ create mode 100644 src/vgahooks.h
+
+diff --git a/src/optionroms.c b/src/optionroms.c
+index e906ab97..fcce7900 100644
+--- a/src/optionroms.c
++++ b/src/optionroms.c
+@@ -22,6 +22,7 @@
+ #include "string.h" // memset
+ #include "util.h" // get_pnp_offset
+ #include "tcgbios.h" // tpm_*
++#include "vgahooks.h" // MXM30SIS
+ 
+ static int EnforceChecksum, S3ResumeVga, RunPCIroms;
+ 
+@@ -463,6 +464,14 @@ vgarom_setup(void)
+     RunPCIroms = romfile_loadint("etc/pci-optionrom-exec", 2);
+     ScreenAndDebug = romfile_loadint("etc/screen-and-debug", 1);
+ 
++    // Load MXM 3.0 System Information Structure
++    void *mxm_sis = romfile_loadfile_g("mxm-30-sis", NULL, &malloc_low, 0);
++    if (mxm_sis) {
++        MXM30SIS = (u32)mxm_sis;
++    } else {
++        MXM30SIS = 0;
++    }
++
+     // Clear option rom memory
+     memset((void*)BUILD_ROM_START, 0, rom_get_max() - BUILD_ROM_START);
+ 
+diff --git a/src/vgahooks.c b/src/vgahooks.c
+index 1f149532..a94840b2 100644
+--- a/src/vgahooks.c
++++ b/src/vgahooks.c
+@@ -18,8 +18,10 @@
+ #define VH_VIA 1
+ #define VH_INTEL 2
+ #define VH_SMI 3
++#define VH_MXM 4
+ 
+ int VGAHookHandlerType VARFSEG;
++u32 MXM30SIS VARFSEG;
+ 
+ static void
+ handle_155fXX(struct bregs *regs)
+@@ -59,6 +61,7 @@ via_155f02(struct bregs *regs)
+     dprintf(1, "Warning: VGA TV/CRT output type is hardcoded\n");
+ }
+ 
++
+ static void
+ via_155f18(struct bregs *regs)
+ {
+@@ -296,6 +299,69 @@ winent_mb6047_setup(struct pci_device *pci)
+     SmiBootDisplay = 0x02;
+ }
+ 
++/****************************************************************
++ * MXM VGA hooks
++ ****************************************************************/
++
++// Function 0: Return Specification Support Level
++static void
++mxm_V30_F00(struct bregs *regs)
++{
++    regs->ax = 0x005f; // Success
++    regs->bl = 0x30; // MXM 3.0
++    regs->cx = 0x0003; // Supported Functions
++    set_success(regs);
++}
++
++// Function 1: Return a Pointer to the MXM Structure
++static void
++mxm_V30_F01(struct bregs *regs)
++{
++    switch (regs->cx) {
++    case 0x0030:
++        regs->ax = 0x005f; // Success
++        regs->es = GET_GLOBAL(MXM30SIS)/16;
++        regs->di = GET_GLOBAL(MXM30SIS)%16;
++        set_success(regs);
++        break;
++    default:
++        handle_155fXX(regs);
++        break;
++    }
++}
++
++static void
++mxm_V30(struct bregs *regs)
++{
++    switch (regs->bx) {
++    case 0xff00: mxm_V30_F00(regs); break;
++    case 0xff01: mxm_V30_F01(regs); break;
++    default:   handle_155fXX(regs); break;
++    }
++}
++
++static void
++mxm_155f80(struct bregs *regs)
++{
++    // TODO: implement other versions, like 2.1
++    mxm_V30(regs);
++}
++
++static void
++mxm_155f(struct bregs *regs)
++{
++    switch (regs->al) {
++    case 0x80: mxm_155f80(regs); break;
++    default:   handle_155fXX(regs); break;
++    }
++}
++
++void
++mxm_setup(void)
++{
++    VGAHookHandlerType = VH_MXM;
++}
++
+ /****************************************************************
+  * Entry and setup
+  ****************************************************************/
+@@ -313,6 +379,7 @@ handle_155f(struct bregs *regs)
+     switch (htype) {
+     case VH_VIA:   via_155f(regs); break;
+     case VH_INTEL: intel_155f(regs); break;
++    case VH_MXM:   mxm_155f(regs); break;
+     default:       handle_155fXX(regs); break;
+     }
+ }
+@@ -352,4 +419,6 @@ vgahook_setup(struct pci_device *pci)
+         via_setup(pci);
+     else if (pci->vendor == PCI_VENDOR_ID_INTEL)
+         intel_setup(pci);
++    else if (GET_GLOBAL(MXM30SIS))
++        mxm_setup();
+ }
+diff --git a/src/vgahooks.h b/src/vgahooks.h
+new file mode 100644
+index 00000000..f0c203af
+--- /dev/null
++++ b/src/vgahooks.h
+@@ -0,0 +1,9 @@
++#ifndef __VGAHOOKS_H
++#define __VGAHOOKS_H
++
++#include "types.h" // u32
++
++extern u32 MXM30SIS;
++
++
++#endif // vgahooks.h
+-- 
+2.43.0
+