From 7f4e9de6d5ed1963f84bb10300d3ee0cc8121a66 Mon Sep 17 00:00:00 2001
From: Berkus Decker <berkus+github@metta.systems>
Date: Sat, 22 Jan 2022 02:13:41 +0200
Subject: [PATCH] =?UTF-8?q?feat:=20=E2=9C=A8=20Update=20BcmHost=20for=20rp?=
 =?UTF-8?q?i4?=
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---
 machine/src/platform/rpi3/mod.rs | 75 ++++++++++++++++++++++++++++----
 1 file changed, 67 insertions(+), 8 deletions(-)

diff --git a/machine/src/platform/rpi3/mod.rs b/machine/src/platform/rpi3/mod.rs
index 38fab56..aba0b4b 100644
--- a/machine/src/platform/rpi3/mod.rs
+++ b/machine/src/platform/rpi3/mod.rs
@@ -19,11 +19,55 @@ pub mod vc;
 
 pub struct BcmHost;
 
+// Per <https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#peripheral-addresses>:
+//
+// SoC     Peripheral Address	Peripheral Size	SDRAM Address	Source
+// BCM2835 0x20000000           0x01000000      0x40000000      <https://github.com/raspberrypi/linux/blob/7f465f823c2ecbade5877b8bbcb2093a8060cb0e/arch/arm/boot/dts/bcm2835.dtsi#L21>
+// BCM2836 0x3f000000           0x01000000      0xc0000000      <https://github.com/raspberrypi/linux/blob/7f465f823c2ecbade5877b8bbcb2093a8060cb0e/arch/arm/boot/dts/bcm2836.dtsi#L10>
+// BCM2837 0x3f000000           0x01000000      0xc0000000      <https://github.com/raspberrypi/linux/blob/7f465f823c2ecbade5877b8bbcb2093a8060cb0e/arch/arm/boot/dts/bcm2837.dtsi#L9>
+// BCM2711 0xfe000000           0x01800000      0xc0000000      <https://github.com/raspberrypi/linux/blob/7f465f823c2ecbade5877b8bbcb2093a8060cb0e/arch/arm/boot/dts/bcm2711.dtsi#L41>
+
+// <https://www.raspberrypi.com/documentation/computers/processors.html>
+// The BCM2835 is the Broadcom chip used in the Raspberry Pi Model A, B, B+, the Compute Module, and the Raspberry Pi Zero.
+// The BCM2836 is used in the Raspberry Pi 2 Model B.
+// The BCM2837 is used in the Raspberry Pi 3, and in later models of the Raspberry Pi 2.
+// The BCM2837B0 is used in the Raspberry Pi 3B+ and 3A+.
+// The BCM2711 is used in the Raspberry Pi 4 Model B.
+// RP3A0 (BCM2710A1 — which is the die packaged inside the BCM2837 chip - Raspberry Pi 3) used in Raspberry Pi Zero 2 W
+
+// Machine   Board  Chip
+// raspi1    raspi  bcm2835
+// raspi1    raspi  bcm2835
+// raspi3b+  raspi  bcm2837
+// raspi4    raspi  bcm2711
+
 impl BcmHost {
+    /// At which address to load the kernel binary.
+    pub const fn kernel_load_address() -> u64 {
+        0x8_0000
+    }
+
+    /// As per <https://www.raspberrypi.org/forums/viewtopic.php?p=1170522#p1170522>
+    ///
+    pub fn bus2phys(bus: usize) -> usize {
+        bus & !0xc000_0000
+    }
+
+    pub fn phys2bus(phys: usize) -> usize {
+        phys | 0xc000_0000
+    }
+}
+
+// RasPi3B+
+#[cfg(feature = "rpi3")]
+impl BcmHost {
+    /// Name of the hardware device this BcmHost is compiled for.
+    pub const fn board_name() -> &'static str {
+        "Raspberry Pi 3+"
+    }
+
     /// This returns the ARM-side physical address where peripherals are mapped.
     ///
-    /// As per <https://www.raspberrypi.org/documentation/hardware/raspberrypi/peripheral_addresses.md>
-    /// BCM SOC could address only 1Gb of memory, so 0x4000_0000 is the high watermark.
     pub const fn get_peripheral_address() -> usize {
         0x3f00_0000
     }
@@ -37,14 +81,29 @@ impl BcmHost {
     pub const fn get_sdram_address() -> usize {
         0xc000_0000 // uncached
     }
+}
 
-    /// As per <https://www.raspberrypi.org/forums/viewtopic.php?p=1170522#p1170522>
-    ///
-    pub fn bus2phys(bus: usize) -> usize {
-        bus & !0xc000_0000
+// RasPi4
+#[cfg(feature = "rpi4")]
+impl BcmHost {
+    /// Name of the hardware device this BcmHost is compiled for.
+    pub const fn board_name() -> &'static str {
+        "Raspberry Pi 4+"
     }
 
-    pub fn phys2bus(phys: usize) -> usize {
-        phys | 0xc000_0000
+    /// This returns the ARM-side physical address where peripherals are mapped.
+    ///
+    pub const fn get_peripheral_address() -> usize {
+        0xfe00_0000
+    }
+
+    /// This returns the size of the peripherals' space.
+    pub const fn get_peripheral_size() -> usize {
+        0x0180_0000
+    }
+
+    /// This returns the bus address of the SDRAM.
+    pub const fn get_sdram_address() -> usize {
+        0xc000_0000 // uncached
     }
 }