Add memory map code from u-boot [sq]

src/arch/aarch64/mod.rs

@@ -111,3 +111,47 @@ pub fn write_ttbr_tcr_mair(el: u8, base: u64, tcr: u64, attr: u64) {
         asm!("isb" :::: "volatile");
     }
 }
+
+struct MemMapRegion {
+    virt: usize,
+    phys: usize,
+    size: usize,
+    attr: usize,
+}
+
+impl MemMapRegion {}
+
+// const bcm2837_mem_map: MemMapRegion[] = {
+//     MemMapRegion {
+//         virt: 0x00000000,
+//         phys: 0x00000000,
+//         size: 0x3f000000,
+//         attr: PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE, // mair
+//     },
+//     MemMapRegion {
+//         virt: 0x3f000000,
+//         phys: 0x3f000000,
+//         size: 0x01000000,
+//         attr: PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) | PTE_BLOCK_NON_SHARE | PTE_BLOCK_PXN | PTE_BLOCK_UXN,
+//     }
+// }
+
+pub struct BcmHost;
+
+impl BcmHost {
+    // As per https://www.raspberrypi.org/documentation/hardware/raspberrypi/peripheral_addresses.md
+    /// This returns the ARM-side physical address where peripherals are mapped.
+    pub fn get_peripheral_address() -> usize {
+        0x3f00_0000
+    }
+
+    /// This returns the size of the peripheral's space.
+    pub fn get_peripheral_size() -> usize {
+        0x0100_0000
+    }
+
+    /// This returns the bus address of the SDRAM.
+    pub fn get_sdram_address() -> usize {
+        0xC000_0000 // uncached
+    }
+}