diff --git a/Makefile b/Makefile
index 24d4626..ac9edba 100644
--- a/Makefile
+++ b/Makefile
@@ -463,7 +463,7 @@ ovmf: $(OVMF_CODE) $(OVMF_VARS)
 all: $(OVMF_CODE) $(OVMF_VARS)
 
 qemu-uefi: esp $(BUILD)/schfs.img $(OVMF_CODE) $(OVMF_VARS)
-	$(QEMU) -machine pc-i440fx-9.2 	    -drive if=pflash,format=raw,unit=0,readonly=on,file=$(OVMF_CODE) 	    -drive if=pflash,format=raw,unit=1,file=$(OVMF_VARS) 	    -drive file=fat:rw:$(BUILD)/esp,index=0,media=disk 	    -drive file=$(BUILD)/schfs.img,format=raw,index=1,media=disk 	    -m 1G -smp 1 -cpu qemu64,+rdtscp -serial mon:stdio $(QEMU_DISPLAY) $(QEMU_INPUT)
+	$(QEMU) -machine pc-i440fx-9.2 	    -drive if=pflash,format=raw,unit=0,readonly=on,file=$(OVMF_CODE) 	    -drive if=pflash,format=raw,unit=1,file=$(OVMF_VARS) 	    -drive file=fat:rw:$(BUILD)/esp,index=0,media=disk,format=raw 	    -drive file=$(BUILD)/schfs.img,format=raw,index=1,media=disk 	    -m 1G -smp 1 -cpu qemu64,+rdtscp -serial mon:stdio $(QEMU_DISPLAY) $(QEMU_INPUT)
 
 # Build the ramdisk-root variant. This is a target rather than just
 # "make RAMROOT=1" because toggling RAMROOT changes CFLAGS (-DRAMDISK_ROOT),
@@ -898,7 +898,7 @@ schcom-test: esp $(BUILD)/schfs.img
 # ends up with a writable firmware image and nobody notices.
 OVMF_DRIVES = -drive if=pflash,format=raw,unit=0,readonly=on,file=$(OVMF_CODE) \
               -drive if=pflash,format=raw,unit=1,file=$(OVMF_VARS) \
-              -drive file=fat:rw:$(BUILD)/esp,index=0,media=disk \
+              -drive file=fat:rw:$(BUILD)/esp,index=0,media=disk,format=raw \
               -drive file=$(BUILD)/schfs.img,format=raw,index=1,media=disk
 
 qemu-kvm: esp $(BUILD)/schfs.img $(OVMF_CODE) $(OVMF_VARS)
diff --git a/boot/uefi/main.c b/boot/uefi/main.c
index 9307d17..b247709 100644
--- a/boot/uefi/main.c
+++ b/boot/uefi/main.c
@@ -570,6 +570,194 @@ res_choose(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
     }
 }
 
+/* Both defined below, next to the hand-off code they belong to. The system
+ * information panel reads the same two facts the kernel will be handed, on
+ * purpose: a panel with its own idea of what counts as usable memory, or its
+ * own ACPI search, would be a second implementation to keep in step. */
+static UINT32 efi_type_to_e820(UINT32 t);
+static UINT64 find_rsdp(void);
+
+/* CPU brand string, from CPUID leaves 0x80000002..4. Forty-eight bytes of
+ * ASCII split across twelve registers, usually with leading spaces on Intel
+ * parts, so it is trimmed on the way out. A CPU that does not implement the
+ * extended leaves reports a maximum below 0x80000004, and there is nothing to
+ * substitute -- saying "unknown" is better than printing whatever registers
+ * happened to hold. */
+static void
+cpu_brand(char *out, int cap)
+{
+    UINT32 eax = 0, ebx = 0, ecx = 0, edx = 0;
+    __asm__ volatile("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
+                             : "a"(0x80000000u));
+    if (eax < 0x80000004u) {
+        int i = 0;
+        for (const char *q = "unknown"; *q && i < cap - 1; q++) out[i++] = *q;
+        out[i] = 0;
+        return;
+    }
+
+    char raw[49];
+    int n = 0;
+    for (UINT32 leaf = 0x80000002u; leaf <= 0x80000004u; leaf++) {
+        __asm__ volatile("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
+                                 : "a"(leaf));
+        UINT32 regs[4] = { eax, ebx, ecx, edx };
+        for (int r = 0; r < 4; r++)
+            for (int b = 0; b < 4; b++)
+                raw[n++] = (char)((regs[r] >> (b * 8)) & 0xFF);
+    }
+    raw[48] = 0;
+
+    const char *src = raw;
+    while (*src == ' ') src++;
+    int i = 0;
+    while (*src && i < cap - 1) out[i++] = *src++;
+    while (i > 0 && out[i - 1] == ' ') i--;
+    out[i] = 0;
+}
+
+/* Total conventional memory, in MB, from the UEFI memory map.
+ *
+ * This is a *look*, not the hand-off: GetMemoryMap is called again at exit
+ * because any allocation between here and there invalidates the map key, and
+ * calling it once for both purposes is how a loader gets EFI_INVALID_PARAMETER
+ * from ExitBootServices long after the mistake. The count is deliberately of
+ * the types the kernel will treat as usable, so it matches what the system
+ * later reports rather than what the firmware owns. */
+static UINT64
+memory_mb(void)
+{
+    UINTN size = 0, mapkey = 0, dsize = 0;
+    UINT32 dver = 0;
+    static char buf[16384];
+
+    size = sizeof buf;
+    if (EFI_ERROR(BS->GetMemoryMap(&size, (EFI_MEMORY_DESCRIPTOR *)buf,
+                                   &mapkey, &dsize, &dver)))
+        return 0;
+
+    UINT64 pages = 0;
+    for (UINTN off = 0; off + dsize <= size; off += dsize) {
+        EFI_MEMORY_DESCRIPTOR *d = (EFI_MEMORY_DESCRIPTOR *)(buf + off);
+        if (efi_type_to_e820(d->Type) == E820_USABLE)
+            pages += d->NumberOfPages;
+    }
+    return (pages * 4096u) / (1024u * 1024u);
+}
+
+/* Narrow a CHAR16 string into ASCII for the panel. The firmware vendor is the
+ * only UTF-16 string on this screen; anything outside ASCII becomes '?' rather
+ * than being silently dropped, so a name that does not fit still looks like a
+ * name. */
+static void
+narrow(const CHAR16 *src, char *out, int cap)
+{
+    int i = 0;
+    if (src)
+        while (src[i] && i < cap - 1) {
+            CHAR16 c = src[i];
+            out[i] = (c >= 0x20 && c < 0x7F) ? (char)c : '?';
+            i++;
+        }
+    out[i] = 0;
+}
+
+/* The system information screen.
+ *
+ * Everything here is read at the moment it is shown rather than captured at
+ * startup: the resolution can have been changed by the row above it, and a
+ * panel that still reports the mode the machine booted with is worse than no
+ * panel. */
+static void
+sys_info(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
+{
+    char vendor[40], cpu[52], mode[32], mem[24], fw[24], spec[24], acpi[24];
+
+    narrow(ST->FirmwareVendor, vendor, sizeof vendor);
+    cpu_brand(cpu, sizeof cpu);
+
+    {
+        char w[16], h[16];
+        u64_to_dec(gop->Mode->Info->HorizontalResolution, w, sizeof w);
+        u64_to_dec(gop->Mode->Info->VerticalResolution, h, sizeof h);
+        int i = 0;
+        for (char *q = w; *q && i < (int)sizeof mode - 1; q++) mode[i++] = *q;
+        if (i < (int)sizeof mode - 1) mode[i++] = 'x';
+        for (char *q = h; *q && i < (int)sizeof mode - 1; q++) mode[i++] = *q;
+        mode[i] = 0;
+    }
+
+    {
+        char n[24];
+        u64_to_dec(memory_mb(), n, sizeof n);
+        int i = 0;
+        for (char *q = n; *q && i < (int)sizeof mem - 1; q++) mem[i++] = *q;
+        for (const char *q = " MB usable"; *q && i < (int)sizeof mem - 1; q++)
+            mem[i++] = *q;
+        mem[i] = 0;
+    }
+
+    /* The firmware's own revision, and the UEFI revision it implements. These
+     * disagree often and the difference matters when reading a bug report:
+     * one names the build, the other names the contract. */
+    {
+        char hi[16], lo[16];
+        u64_to_dec(ST->FirmwareRevision >> 16, hi, sizeof hi);
+        u64_to_dec(ST->FirmwareRevision & 0xFFFF, lo, sizeof lo);
+        int i = 0;
+        for (char *q = hi; *q && i < (int)sizeof fw - 1; q++) fw[i++] = *q;
+        if (i < (int)sizeof fw - 1) fw[i++] = '.';
+        for (char *q = lo; *q && i < (int)sizeof fw - 1; q++) fw[i++] = *q;
+        fw[i] = 0;
+    }
+    {
+        /* EFI_TABLE_HEADER is { UINT64 Signature; UINT32 Revision; ... }, so
+         * Revision is at offset 8. At offset 4 this read the upper half of the
+         * "IBI SYST" signature and displayed it as "21587.2286". */
+        UINT32 rev = *(UINT32 *)(ST->Hdr + 8);
+        char hi[16], lo[16];
+        u64_to_dec(rev >> 16, hi, sizeof hi);
+        u64_to_dec((rev & 0xFFFF) / 10, lo, sizeof lo);
+        int i = 0;
+        for (char *q = hi; *q && i < (int)sizeof spec - 1; q++) spec[i++] = *q;
+        if (i < (int)sizeof spec - 1) spec[i++] = '.';
+        for (char *q = lo; *q && i < (int)sizeof spec - 1; q++) spec[i++] = *q;
+        spec[i] = 0;
+    }
+
+    /* Whether ACPI was found, because its absence is not cosmetic: no RSDP
+     * means no MADT, no IOAPIC and no SMP, and that has already been debugged
+     * once from the far end. */
+    {
+        const char *v = find_rsdp() ? "present" : "NOT FOUND";
+        int i = 0;
+        for (const char *q = v; *q && i < (int)sizeof acpi - 1; q++) acpi[i++] = *q;
+        acpi[i] = 0;
+    }
+
+    static const char *const labels[] = {
+        "Firmware", "Firmware revision", "UEFI revision",
+        "Processor", "Memory", "Display", "ACPI",
+    };
+    const char *values[7];
+    values[0] = vendor;
+    values[1] = fw;
+    values[2] = spec;
+    values[3] = cpu;
+    values[4] = mem;
+    values[5] = mode;
+    values[6] = acpi;
+
+    ui_panel("System Information", labels, values, 7, "Any key to go back");
+
+    EFI_INPUT_KEY key;
+    for (;;) {
+        if (ST->ConIn && !EFI_ERROR(ST->ConIn->ReadKeyStroke(ST->ConIn, &key)))
+            return;
+        BS->Stall(10000);
+    }
+}
+
 static int
 boot_menu(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
 {
@@ -589,14 +777,15 @@ boot_menu(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
 
         res_row(gop, resbuf, sizeof resbuf);
 
-        const char *items[4];
+        const char *items[5];
         items[0] = "Boot SchOS";
         items[1] = "Boot SchOS (verbose)";
         items[2] = resbuf;
-        items[3] = "Reboot to firmware";
+        items[3] = "System Information";
+        items[4] = "Reboot to firmware";
 
-        ui_menu("Boot Manager", items, 4, selected,
-                "W/S or 1-4 to choose, Enter to select");
+        ui_menu("Boot Manager", items, 5, selected,
+                "W/S or 1-5 to choose, Enter to select");
 
         EFI_INPUT_KEY key;
         CHAR16 c = 0;
@@ -609,17 +798,18 @@ boot_menu(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
             BS->Stall(10000);
         }
 
-        if (scan == 0x01) { selected = (selected + 3) % 4; continue; }  /* up */
-        if (scan == 0x02) { selected = (selected + 1) % 4; continue; }  /* down */
-        if (c == L'w' || c == L'W') { selected = (selected + 3) % 4; continue; }
-        if (c == L's' || c == L'S') { selected = (selected + 1) % 4; continue; }
-        if (c >= L'1' && c <= L'4') { selected = (int)(c - L'1'); continue; }
+        if (scan == 0x01) { selected = (selected + 4) % 5; continue; }  /* up */
+        if (scan == 0x02) { selected = (selected + 1) % 5; continue; }  /* down */
+        if (c == L'w' || c == L'W') { selected = (selected + 4) % 5; continue; }
+        if (c == L's' || c == L'S') { selected = (selected + 1) % 5; continue; }
+        if (c >= L'1' && c <= L'5') { selected = (int)(c - L'1'); continue; }
 
         if (c == L'\r' || c == L'\n') {
             if (selected == 0) return 0;
             if (selected == 1) return 1;
             if (selected == 2) { res_choose(gop); continue; }
-            if (selected == 3) {
+            if (selected == 3) { sys_info(gop); continue; }
+            if (selected == 4) {
                 ui_clear();
                 ui_text_centered((int)ui_height() / 2, "Halted -- reset to reach firmware setup",
                                  0xB9BEC7u);
diff --git a/run.ps1 b/run.ps1
index 628dbd4..eb15873 100644
--- a/run.ps1
+++ b/run.ps1
@@ -121,7 +121,7 @@ if ($buf[0] -ne 0x46 -or $buf[1] -ne 0x68 -or $buf[2] -ne 0x63 -or $buf[3] -ne 0
 $qemuArgs = @(
     '-drive', "if=pflash,format=raw,unit=0,readonly=on,file=$code"
     '-drive', "if=pflash,format=raw,unit=1,file=$runVars"
-    '-drive', "file=fat:rw:$esp,index=0,media=disk"
+    '-drive', "file=fat:rw:$esp,index=0,media=disk,format=raw"
     '-drive', "file=$hdb,format=raw,index=1,media=disk"
     '-m', '1G'
     '-smp', '2'
diff --git a/tools/posix/schcom_test.sh b/tools/posix/schcom_test.sh
index 551fa48..7b994b1 100644
--- a/tools/posix/schcom_test.sh
+++ b/tools/posix/schcom_test.sh
@@ -46,7 +46,7 @@ EOF
       -machine pc-i440fx-9.2 -cpu qemu64,+rdtscp \
       -drive if=pflash,format=raw,unit=0,readonly=on,file=build/OVMF_CODE.fd \
       -drive if=pflash,format=raw,unit=1,file=build/schcom-OVMF_VARS.fd \
-      -drive file=fat:rw:build/esp,index=0,media=disk \
+      -drive file=fat:rw:build/esp,index=0,media=disk,format=raw \
       -drive file=build/schfs.img,format=raw,index=1,media=disk \
       -m 1G -smp 1 \
       -display none -vga std \
diff --git a/tools/windows/bootcheck.ps1 b/tools/windows/bootcheck.ps1
index 1f9c38b..5a396d2 100644
--- a/tools/windows/bootcheck.ps1
+++ b/tools/windows/bootcheck.ps1
@@ -272,7 +272,7 @@ $drives = if ($Iso) {
     if (-not (Test-Path (Join-Path $esp 'EFI/BOOT/BOOTX64.EFI'))) {
         throw "no staged ESP at $esp -- run 'make esp' first"
     }
-    $firmware + @("-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    $firmware + @("-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
                   "-drive file=`"$hdb`",format=raw,index=1,media=disk")
 }
 
diff --git a/tools/windows/crashshot.ps1 b/tools/windows/crashshot.ps1
index cee2edc..ee8c6ab 100644
--- a/tools/windows/crashshot.ps1
+++ b/tools/windows/crashshot.ps1
@@ -80,7 +80,7 @@ $psi.FileName = $Qemu
 $psi.Arguments = @(
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk"
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
     '-display none'
diff --git a/tools/windows/dispshot.ps1 b/tools/windows/dispshot.ps1
index e38a62e..62e2f60 100644
--- a/tools/windows/dispshot.ps1
+++ b/tools/windows/dispshot.ps1
@@ -85,7 +85,7 @@ $psi.FileName = $Qemu
 $psi.Arguments = @(
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk"
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
     '-display none'
diff --git a/tools/windows/fbshot.ps1 b/tools/windows/fbshot.ps1
index a6445c4..34f5840 100644
--- a/tools/windows/fbshot.ps1
+++ b/tools/windows/fbshot.ps1
@@ -75,7 +75,7 @@ $psi.FileName = $Qemu
 $psi.Arguments = @(
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk"
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
     '-display none'
diff --git a/tools/windows/splashshot.ps1 b/tools/windows/splashshot.ps1
index 8dfd71a..6587451 100644
--- a/tools/windows/splashshot.ps1
+++ b/tools/windows/splashshot.ps1
@@ -90,7 +90,7 @@ $psi.Arguments = @(
     # are untouched either way.
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk,file.locking=off"
     '-snapshot'
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
diff --git a/tools/windows/textshot.ps1 b/tools/windows/textshot.ps1
index be2b97d..669ee76 100644
--- a/tools/windows/textshot.ps1
+++ b/tools/windows/textshot.ps1
@@ -85,7 +85,7 @@ $psi.FileName = $Qemu
 $psi.Arguments = @(
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk"
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
     '-display none'
diff --git a/tools/windows/ttyshot.ps1 b/tools/windows/ttyshot.ps1
index 54b53db..c426df3 100644
--- a/tools/windows/ttyshot.ps1
+++ b/tools/windows/ttyshot.ps1
@@ -88,7 +88,7 @@ $psi.FileName = $Qemu
 $psi.Arguments = @(
     "-drive if=pflash,format=raw,unit=0,readonly=on,file=`"$code`""
     "-drive if=pflash,format=raw,unit=1,file=`"$runVars`""
-    "-drive file=fat:rw:`"$esp`",index=0,media=disk"
+    "-drive file=fat:rw:`"$esp`",index=0,media=disk,format=raw"
     "-drive file=`"$hdb`",format=raw,index=1,media=disk"
     '-m 1G -smp 1 -cpu qemu64,+rdtscp -machine pc-i440fx-9.2'
     '-display none'