Implement "mach dtb <filename.dtb>" in efiboot(8). This way we can

provide our own FDT if the BIOS doesn't supply one, or even override
the supplied one.

Idea from and ok kettenis@

diff --git a/sys/arch/arm64/stand/efiboot/efiboot.c b/sys/arch/arm64/stand/efiboot/efiboot.c
index df21ad2..fa8fefb 100644 (file)
--- a/sys/arch/arm64/stand/efiboot/efiboot.c
+++ b/sys/arch/arm64/stand/efiboot/efiboot.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: efiboot.c,v 1.18 2018/07/10 13:05:37 kettenis Exp $   */
+/*     $OpenBSD: efiboot.c,v 1.19 2018/08/19 14:09:41 patrick Exp $    */
 
 /*
  * Copyright (c) 2015 YASUOKA Masahiko <yasuoka@yasuoka.net>
@@ -19,6 +19,7 @@
 
 #include <sys/param.h>
 #include <sys/queue.h>
+#include <sys/stat.h>
 #include <dev/cons.h>
 #include <sys/disklabel.h>
 
@@ -359,6 +360,7 @@ efi_framebuffer(void)
 }
 
 int acpi = 0;
+void *fdt = NULL;
 char *bootmac = NULL;
 static EFI_GUID fdt_guid = FDT_TABLE_GUID;
 
@@ -367,7 +369,6 @@ static EFI_GUID fdt_guid = FDT_TABLE_GUID;
 void *
 efi_makebootargs(char *bootargs)
 {
-       void *fdt = NULL;
        u_char bootduid[8];
        u_char zero[8] = { 0 };
        uint64_t uefi_system_table = htobe64((uintptr_t)ST);
@@ -375,10 +376,12 @@ efi_makebootargs(char *bootargs)
        size_t len;
        int i;
 
-       for (i = 0; i < ST->NumberOfTableEntries; i++) {
-               if (efi_guidcmp(&fdt_guid,
-                   &ST->ConfigurationTable[i].VendorGuid) == 0)
-                       fdt = ST->ConfigurationTable[i].VendorTable;
+       if (fdt == NULL) {
+               for (i = 0; i < ST->NumberOfTableEntries; i++) {
+                       if (efi_guidcmp(&fdt_guid,
+                           &ST->ConfigurationTable[i].VendorGuid) == 0)
+                               fdt = ST->ConfigurationTable[i].VendorTable;
+               }
        }
 
        if (fdt == NULL || acpi)
@@ -741,11 +744,13 @@ efi_memprobe_find(UINTN pages, UINTN align, EFI_PHYSICAL_ADDRESS *addr)
  */
 
 int Xacpi_efi(void);
+int Xdtb_efi(void);
 int Xexit_efi(void);
 int Xpoweroff_efi(void);
 
 const struct cmd_table cmd_machine[] = {
        { "acpi",       CMDT_CMD, Xacpi_efi },
+       { "dtb",        CMDT_CMD, Xdtb_efi },
        { "exit",       CMDT_CMD, Xexit_efi },
        { "poweroff",   CMDT_CMD, Xpoweroff_efi },
        { NULL, 0 }
@@ -758,6 +763,40 @@ Xacpi_efi(void)
        return (0);
 }
 
+int
+Xdtb_efi(void)
+{
+       EFI_PHYSICAL_ADDRESS addr;
+       char path[MAXPATHLEN];
+       struct stat sb;
+       int fd;
+
+#define O_RDONLY       0
+
+       if (cmd.argc != 2)
+               return (1);
+
+       snprintf(path, sizeof(path), "%s:%s", cmd.bootdev, cmd.argv[1]);
+
+       fd = open(path, O_RDONLY);
+       if (fd < 0 || fstat(fd, &sb) == -1) {
+               printf("cannot open %s\n", path);
+               return (1);
+       }
+       if (efi_memprobe_find(EFI_SIZE_TO_PAGES(sb.st_size),
+           0x1000, &addr) != EFI_SUCCESS) {
+               printf("cannot allocate memory for %s\n", path);
+               return (1);
+       }
+       if (read(fd, (void *)addr, sb.st_size) != sb.st_size) {
+               printf("cannot read from %s\n", path);
+               return (1);
+       }
+
+       fdt = (void *)addr;
+       return (0);
+}
+
 int
 Xexit_efi(void)
 {