[Minios-devel] [UNIKRAFT PATCHv5 34/46] plat/kvm: Initialize console from device tree for Arm64

[Wei Chen <wei.chen@xxxxxxx>]

We have implemented a console for early debug console. We had
hardcode the PL011 UART base address. But, after device tree
is ready, we can initialize console from device tree.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 plat/common/arm/console.c | 57 +++++++++++++++++++++++++++++++++++++++
 plat/kvm/arm/setup.c      |  3 +++
 2 files changed, 60 insertions(+)

diff --git a/plat/common/arm/console.c b/plat/common/arm/console.c
index 5d1b5d4..c638033 100644
--- a/plat/common/arm/console.c
+++ b/plat/common/arm/console.c
@@ -18,6 +18,7 @@
  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <libfdt.h>
 #include <uk/plat/console.h>
 #include <uk/assert.h>
 #include <arm/cpu.h>
@@ -73,6 +74,62 @@ static uint64_t pl011_uart_bas;
 #define PL011_REG_READ(r)      ioreg_read16(PL011_REG(r))
 #define PL011_REG_WRITE(r, v)  ioreg_write16(PL011_REG(r), v)
 
+extern void *_libkvmplat_dtb;
+
+static void init_pl011(uint64_t bas)
+{
+       pl011_uart_bas = bas;
+
+       /* Mask all interrupts */
+       PL011_REG_WRITE(REG_UARTIMSC_OFFSET, \
+               PL011_REG_READ(REG_UARTIMSC_OFFSET) & 0xf800);
+
+       /* Clear all interrupts */
+       PL011_REG_WRITE(REG_UARTICR_OFFSET, 0x07ff);
+
+       /* Disable UART for configuration */
+       PL011_REG_WRITE(REG_UARTCR_OFFSET, 0);
+
+       /* Select 8-bits data transmit and receive */
+       PL011_REG_WRITE(REG_UARTLCR_H_OFFSET, \
+               (PL011_REG_READ(REG_UARTLCR_H_OFFSET) & 0xff00) | LCR_H_WLEN8);
+
+       /* Just enable UART and data transmit/receive */
+       PL011_REG_WRITE(REG_UARTCR_OFFSET, CR_TXE | CR_UARTEN);
+}
+
+void _libkvmplat_init_console(void)
+{
+       int offset, len, naddr, nsize;
+       const uint64_t *regs;
+       uint64_t reg_uart_bas;
+
+       uk_printd(DLVL_INFO, "Serial initializing\n");
+
+       offset = fdt_node_offset_by_compatible(_libkvmplat_dtb, \
+                                       -1, "arm,pl011");
+       if (offset < 0)
+               UK_CRASH("No console UART found!\n");
+
+       naddr = fdt_address_cells(_libkvmplat_dtb, offset);
+       if (naddr < 0 || naddr >= FDT_MAX_NCELLS)
+               UK_CRASH("Could not find proper address cells!\n");
+
+       nsize = fdt_size_cells(_libkvmplat_dtb, offset);
+       if (nsize < 0 || nsize >= FDT_MAX_NCELLS)
+               UK_CRASH("Could not find proper size cells!\n");
+
+       regs = fdt_getprop(_libkvmplat_dtb, offset, "reg", &len);
+       if (regs == NULL || (len < (int)sizeof(fdt32_t) * (naddr + nsize)))
+               UK_CRASH("Bad 'reg' property: %p %d\n", regs, len);
+
+       reg_uart_bas = fdt64_to_cpu(regs[0]);
+       uk_printd(DLVL_INFO, "Found PL011 UART on: 0x%lx\n", reg_uart_bas);
+
+       init_pl011(reg_uart_bas);
+       uk_printd(DLVL_INFO, "PL011 UART initialized\n");
+}
+
 int ukplat_coutd(const char *str, uint32_t len)
 {
        return ukplat_coutk(str, len);
diff --git a/plat/kvm/arm/setup.c b/plat/kvm/arm/setup.c
index 19a90ae..aca3444 100644
--- a/plat/kvm/arm/setup.c
+++ b/plat/kvm/arm/setup.c
@@ -19,6 +19,7 @@
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 #include <libfdt.h>
+#include <kvm/console.h>
 #include <uk/assert.h>
 
 void *_libkvmplat_dtb;
@@ -37,5 +38,7 @@ static void _init_dtb(void *dtb_pointer)
 void _libkvmplat_start(void *dtb_pointer)
 {
        _init_dtb(dtb_pointer);
+       _libkvmplat_init_console();
+
        uk_printd(DLVL_INFO, "Entering from KVM (arm64)...\n");
 }
-- 
2.17.1


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