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| author | Jan-Peter Larsson <jan-peter.larsson@arm.com> | 2018-12-20 15:55:56 +0000 |
|---|---|---|
| committer | Giacomo Travaglini <giacomo.travaglini@arm.com> | 2019-01-04 13:24:40 +0000 |
| commit | 1a4a617c7e0728508d63a91a8534fbb4583f630c (patch) | |
| tree | c8f05c9f521bec9880b6db5e796f500cae4799c5 | |
| parent | 272e4aa26d8c99ea2043a12e49ac25b2e81fc7ac (diff) | |
| download | gem5-1a4a617c7e0728508d63a91a8534fbb4583f630c.tar.xz | |
dev, arm: Warn on PL011 DMA disable
The PL011 spec specifies a DMACR register at offset 0x48, which isn't
implemented in the model. Currently any attempt to access the register
results in a panic.
This change swaps the panic for a warning only when software writes into
DMACR to disable DMA, keeping the panic otherwise.
Change-Id: I04586b52df8d5d174536276fd7ae19e77ff4681a
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15279
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
| -rwxr-xr-x[-rw-r--r--] | src/dev/arm/pl011.cc | 12 | ||||
| -rwxr-xr-x[-rw-r--r--] | src/dev/arm/pl011.hh | 1 |
2 files changed, 13 insertions, 0 deletions
diff --git a/src/dev/arm/pl011.cc b/src/dev/arm/pl011.cc index fe73d9674..2e80045e4 100644..100755 --- a/src/dev/arm/pl011.cc +++ b/src/dev/arm/pl011.cc @@ -133,6 +133,10 @@ Pl011::read(PacketPtr pkt) DPRINTF(Uart, "Reading Masked Int status as 0x%x\n", maskInt()); data = maskInt(); break; + case UART_DMACR: + warn("PL011: DMA not supported\n"); + data = 0x0; // DMA never enabled + break; default: if (readId(pkt, AMBA_ID, pioAddr)) { // Hack for variable size accesses @@ -239,6 +243,14 @@ Pl011::write(PacketPtr pkt) dataAvailable(); } break; + case UART_DMACR: + // DMA is not supported, so panic if anyome tries to enable it. + // Bits 0, 1, 2 enables DMA on RX, TX, ERR respectively, others res0. + if (data & 0x7) { + panic("Tried to enable DMA on PL011\n"); + } + warn("PL011: DMA not supported\n"); + break; default: panic("Tried to write PL011 at offset %#x that doesn't exist\n", daddr); break; diff --git a/src/dev/arm/pl011.hh b/src/dev/arm/pl011.hh index 5a92d8890..dac2f6837 100644..100755 --- a/src/dev/arm/pl011.hh +++ b/src/dev/arm/pl011.hh @@ -135,6 +135,7 @@ class Pl011 : public Uart, public AmbaDevice static const int UART_RIS = 0x03C; static const int UART_MIS = 0x040; static const int UART_ICR = 0x044; + static const int UART_DMACR = 0x048; static const uint16_t UART_RIINTR = 1 << 0; static const uint16_t UART_CTSINTR = 1 << 1; |