Author: bdragon Date: Sun Jan 19 04:13:19 2020 New Revision: 356878 URL: https://svnweb.freebsd.org/changeset/base/356878
Log: [PowerPC] Fix 32-bit ubldr calling convention Due to the way u-boot for 32-bit powerpc is compiled, the interrupt code assumes that the GOT pointer (r30) on u-boot is always intact. When making syscalls to u-boot, ensure that we have restored r30 like we found it before we enable interrupts to prevent u-boot from crashing if a timer interrupt was pending. This fixes ubldr on e500 qemu (assuming you have recompiled qemu's u-boot with API support!) Reviewed by: jhibbits Sponsored by: Tag1 Consulting, Inc. Differential Revision: https://reviews.freebsd.org/D23258 Modified: head/stand/powerpc/uboot/start.S Modified: head/stand/powerpc/uboot/start.S ============================================================================== --- head/stand/powerpc/uboot/start.S Sun Jan 19 02:48:56 2020 (r356877) +++ head/stand/powerpc/uboot/start.S Sun Jan 19 04:13:19 2020 (r356878) @@ -38,10 +38,11 @@ _start: lis %r11, uboot_address@ha addi %r11, %r11, uboot_address@l stw %r1, 0(%r11) - /* Save U-Boot's r14 */ + /* Save U-Boot's r14 and r30 */ lis %r11, saved_regs@ha addi %r11, %r11, saved_regs@l stw %r14, 0(%r11) + stw %r30, 4(%r11) /* Disable interrupts */ mfmsr %r11 andi. %r11, %r11, ~0x8000@l @@ -52,14 +53,16 @@ _start: * syscall() */ ENTRY(syscall) - stwu %r1, -16(%r1) + stwu %r1, -32(%r1) mflr %r0 stw %r14, 8(%r1) - stw %r0, 20(%r1) - /* Restore U-Boot's r14 */ + stw %r30, 12(%r1) + stw %r0, 36(%r1) + /* Restore U-Boot's r14 and r30 */ lis %r11, saved_regs@ha addi %r11, %r11, saved_regs@l lwz %r14, 0(%r11) + lwz %r30, 4(%r11) /* Enable interrupts */ mfmsr %r11 ori %r11, %r11, 0x8000@l @@ -79,6 +82,7 @@ ENTRY(syscall) lwz %r0, 4(%r11) mtlr %r0 lwz %r14, 8(%r1) + lwz %r30, 12(%r1) mr %r1, %r11 blr @@ -90,5 +94,6 @@ GLOBAL(syscall_ptr) .long 0 GLOBAL(saved_regs) .long 0 /* R14 */ + .long 0 /* R30 */ GLOBAL(uboot_address) .long 0 _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
